Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length.

[John W E]

FREDERICK SPASHETT – THE DRIFTER TRAWLER BUILD

Have you ever thought what makes us contemplate building a certain model?   Those who are new to the hobby will be drawn into the pastime for one reason or another albeit for pure relaxation or whatever reason.

We will find, once we are established in this hobby, that we have a preference – some prefer modelling Warships, some prefer tugs, some prefer liners etc.

I would personally consider myself, as, what they say a Military Naval builder – as the majority of my models consist of some form of Military vessel.  Every now and then; we as modellers see either a photograph or a plan/actual model of a particular vessel which is not in our chosen field and it triggers something off inside of us – which either brings back memories or we say ‘Oh that is a nice boat’.   This is how the plan for this trawler triggered me – it brought back memories of standing on the quayside of the River Tyne watching the activities on the North side of the River – at the Fish Quay – in my younger days there were lots of boats there, and it was a hive of activity – the sounds and certain smells never go away from the memory  so this is why I have chosen this plan as a build plan.   Because, it holds very special fondness for the past-times and happy memories….

For those who have some experience in building from plans; I suggest you may skip this next part – as this section is dedicated to those who are new to the plan building, but, not new to the field of modelling.

We are going to have a look at the Plans and we are going to have a little insight of the Person who drew the plans.

We will begin with the draftsman, James Pottinger Esquire; James was the draftsman for this particular model plan.  To date James must have drawn approximately 150 plans and he has been doing so for over 30 + years.  Amongst his plans, he has plans for cargo ships, tugs, fishing boats, yachts and other various types.  So, from his selection of plans there is a wide variety to choose from.     There is not a complete list of all of James’ plans – you have to be a bit of a Sherlock Holmes. Do a little bit of digging in the Marine Modelling Magazine and also plans published via the Model Boats Plans Services, there are also several plans published in the Model Shipwright magazine.   So, if you are unable to find what you are actually seeking from the above list; you can contact James Pottinger via email or post details nearer the end of this build thread.

James Pottinger is an engineer by trade and has worked in several fields of the offshore industry and also, sea-going industry – and this shines through in the plans he prepares for us.

So, we know we are going to build from a good accurate set of plans here – at this stage then let us take a look at the plans, to which I have included a scan of a set of plans which can be obtained from the Model Boats Magazine.    This scan, along with the article, comes from the Model Boats Magazine – September 1977 – to which James Pottinger presented an article for the magazine.

[John W E]

There are three main views on the plans of the vessel; the main one is the side profile or elevation as it is named on the plan.

Below it there is what is called the deck plan; and, to the left hand side, is the body plan.   Scattered around there are other small sketches of the Captain, bridge, wheelhouse top and there is also a view of the front of the wheel house & scattered around the rest of the plan are various other items such as the typical deck section and also a suggested method for gaining access to the hull for modelling purposes.

We will concentrate firstly on the 3 main items which concern us on the plan.

The Body Plan

This shows us the shapes of the frames, at certain sections on the elevation plan.  You will see they are numbered; they go from zero to 9½, and, if we look along the side elevation of the plan, you will see the numbers repeated there.   These numbers show the positions of the frames on the side plan.   You will also notice that the deck plan is also in line with the elevation plan.  The numbers can be transposed straight across to the deck plan, giving us the desired total widths of the frames.

If we revert back and have a look at our body plan, you can notice that there are horizontal lines drawn through the frames; and these go from number 1-17 and these horizontal lines are what are known as the water lines.

These lines are of some use to some modellers – to help check the trueness of profiles of the frames.   However, you will notice that these lines have not been repeated on the elevation plan so they won’t be of as much interest to us in this build.

[John W E]

We need to know now what frames and what positions we are going to trace off.   So, first of all, you will see the baseline – Number 1 on the body plan, does not actually start at the very base of the keel.   It actually starts at the plating rebate line, which is where the actual plating on the life-size vessel meets the keel.  So, we take all our vertical measurements from this rebate line.   

We draw in/draw over the centre line of the frames, this is the line which divides the forward looking frames which is on your right-hand side/starboard side as you look at them, and, on your left-hand side/port side are the rear facing frames as though you are standing in the dock looking at the rear of the life-sized vessel.

We have therefore drawn over our centre-line which will go beyond the height of the total frames; to this we then draw a horizontal line 90° to our centre-line.   This will become our building board line.
On my particular model, I drew this line ½ inch above waterline number 17.   

Now have a look at Scan A and this is of the body lines.   I have marked on various items; which we will be concerned with.

We will start off with the very base line; at the bottom of the frames.   This will be called the plate rebate line.   This is where we take all of our sizes from for vertical heights (this particular line).  Then, when we look at the centre of the frames, we will see that there is a centre line drawn vertically and at 90° to the plate rebate line.    Either side of this centre line there are six frames drawn – on the right hand side – numbered from 9 ½ to 6   and on the left hand side of the centre line there are eight frames drawn numbered 0 all the way through to number 5.   

Don’t forget left hand side – PORTSIDE – as though we are standing in the dry dock looking at the vessel from the stern – these would be the frames we would see.

On the right hand side – STARBOARD – side – if we were standing in the dry dock we would be looking at the front of the vessel and we would see the starboard/front frames of the vessel.

Also on scan A you will see we have marked on the building board line, which is – as I have mentioned before – on my particular build is approx ½ inch above waterline 17.   This building board line is parallel to the plate rebate line.

Next we have marked on the bulwark top edge and this is the line which represents the very top edge of the bulwark.   Below that, we will see a deck edge line; which is ‘arrowed’ in – this line represents the level of the deck but only at the edge of the frame.   So, where this line intersects the frame line, this is the height the deck is at that particular frame.   This line takes in no account of the level of the deck at the centre line of the hull; this is only the level at the edge where the line intersects the frame.

Now, if we look at Scan B you will see the same body plan but, only with 2 arrows drawn parallel to the centre line.   This is to aid – determining the height of the deck and also it aids us for when we come to trace.

You will see at the outer edge of the frames, there is a vertical arrow marked as A – now, I have taken frame 7 as an example.   You will see there is a line drawn parallel to the base line through to the centre line.  Where the deck edge intercepts frame 7 that height is transferred to the centre line.   This gives us the height of the deck; however, it doesn’t take into account for camber.

This is as far as we will talk about this particular scan for the time being.

[John W E]

I think at this stage now, we will begin to look into the actual build of the model and we will start with some requirements – such as:
What shall we make the vessel out of?
What motor shall we put in it?
What electrics do we require to go along with the motor?
Are there any special hardware/fittings which we need to purchase?

Materials we are going to construct the model from:    Plywood; some GRP (glass reinforced plastic); some Obechi strips; and, also, for the planking we are going to use Lime strip – plus some maple for the deck planking.

Some side notes about plywood – there are various types of plywood on the market – for home DIY use and also there is marine ply which is used in ‘real’ boat construction:  Modelling ply; as in light-ply and all these ply’s do have some uses.   Some of the plywoods have limited use to us modellers – such as – DIY plywood which is sold in a lot of stores.  This tends to be of little use to us, because, the inner material of the plywood tends to be of a poorer quality then the exterior veneers of the ply – they tend to peel off and split (when it is cut into narrow strips/profiles).

The marine ply as used in the life sized boat building – tends to be on the heavy side for modelling use.  Therefore, this leaves us with the plywood which we purchase from modelling shops/shops which will order in multi-veneer plywood.    I use a birch ply which is made up of 5 veneers – it is a lot more expensive than normal ply – but, this extra price does pay dividends – and the quality stands out when you are actually working with it. 

Now, what about the material we are going to plank the hull in, if we are making the frames from plywood; normally, my preference is to use Obechi planking.   This can be bought in a variety of widths and thicknesses.   I normally use 1.5 mm thick planks, but the width of the planks depend solely on
a) Size of the hull we are building as in length and

b) Shape and the width of the hull

If we are building a hull with very few radius’ in the width of it; as in a vessel with a hard chine construction; we can use relatively broad/wide planks; going up to something like 1 inch in width.   But, if we are building a ‘round’ sectioned hull or in correct terms a displacement hull  where we encounter radius’ on the sides.   This is where we need to reduce the width of the plank to fit the average radius of the hull.  If we try to plank a ‘rounded sectioned’ hull with broad planks – we would tend to end up with a hexagonal affect or a 50 pence piece affect.   So, what we must do is reduce the width of our planks – and we can then faithfully follow the radius in the framework of the hull.

On this particular build I decided to move away from Obechi and try using a relatively new material to me – I am going to use LIME strip planking this time. And the thickness of this Lime strip is on average 1mm to 0.8 mm thickness; and is of 0.8 mm width.    Before I actually used this, I cut a short section off to experiment with it.   To some extent it is slightly better than Obechi to work with – I found when I had put it in boiling water to soak – it actually became more flexible – hey a lot more flexible than Obechi – and it didn’t split either – sometimes Obechi splits across the grain.     Another plus point for the Lime strip is that the majority of the material I had, the grain runs true to the length of the plank – when I have been working with Obechi sometimes, I have had one or two strips of Obechi where the grain has ran diagonally through the width of the plank; rendering it almost useless to use.

I am using 1/8 square Obechi for the stringers.    I have used a /¼square of Obechi for planking support either side of the keel.

The other piece of material I am going to use a lot later on in the build, this is maple and this is going to be used for deck planking it is 0.5 mm thick x 6mm wide – and this material will be discussed later on in the build.

This then, takes care of the wood materials.   Glue – I am going to use a ‘new to the building’ – it is TITEBOND II – basically it has the same characteristics as Evostik Resin W which is what is classed as ‘weatherproof’ and, the only difference between it – I can see – is it is yellow coloured and not white.    It actually does dry yellow too.

We now move on from the glue to the materials we are using for the fibreglass work; the resin was purchased from an Auto shop – in the case of UK – Halfords store.    The manufacturers of the resin are DAVIDSON’S and this is just a standard ‘lay up’ polyester resin and along with this resin is the appropriate hardener, which is a ‘pinky’ coloured paste which comes in a foil tube.

Tissue matting – I have is what is called a ‘Finish tissue matting’ which resembles toilet paper to look at  .

The above listed materials are basically what are required to manufacture the hull.   We now need to move on to the hardware materials.   :-

The propeller shaft propeller shaft I decided to use this time was a standard one I purchased – 4mm shaft diameter x 200 mm long.

The rudder will be built from the plan and made up of 1/8 brass rod; 2 lengths of 1/8 ID (internal diameter) brass tubing.      Also, 2 small pieces of 1/8 ply the same size as the rudder.

The motors; when we discuss motors for particular models we could end up having a long discussion of to’s and fro’s of the size you require for the model; some people do have preferences as in they like to use motors which come from automobile seats from the scrap yard; also there is to take into consideration the power which is required and whether it should in fact be direct drive or through a gearbox.    Bearing this in mind, what I have done in this build is built in a provision, for those who wish to use direct drive – they may with their choice of motor.   This is my choice of motor which I am now going to describe.

The motor I have chosen is a Graupner Speed 500 – along with this, there is an MFA Olympic belt drive gearbox and which has a ratio of 2 to 1 – meaning for every 2 revolutions the small cog on the motor makes  -  it turns the large cog (which is connected to the propeller shaft) once.  Giving us that 2 – 1 ratio.  The reason I have chosen to include a gearbox is that the brushed electric motors of DC current have their best efficiency at the top end of the RPM and operating voltage.    In other words it is most efficient when it is running at 6 volts and approx 17,000 RPM. 

We will be driving a 45mm three bladed propeller; and if we were to direct drive this propeller at 17,000 RPM we would be looking at astronomical amperage.   Somewhere in the region of about 15 – 18 amps; 

This is not very good when one considers using this set up for a 6 volt 4.5 amp battery – it isn’t going to last very long and the battery etc., is going to get very hot.   However if we are going to use the same motor and put the drive through a gearbox of 2-1 ratio – it means the motor may still run at 17,000 RPM, but the prop shaft will only turn at 8,500 RPM which is acceptable for the propeller that we propose to drive.  Doing this will also bring our amperage down and therefore making our duration on the water a lot longer.

We will go into greater detail of choosing speed controllers later on in the build – so – we have now outlined some of our requirements; and the next thing is to commence and actually start the build.

We have spread the plan out and familiarised ourselves with it and we are quite happy – so first of all what we need to do is somehow transfer the outline of the frames; from the body plan to our building material.   This can be done in several ways; we can trace each individual frame off using tracing paper – we can photocopy the body plan, cut out the individual frames from photocopied images and stick them onto our building material – we can use an old method which is still used quite regularly by some builders and it is called the pin and prick method.  This is where you use a dressmaker’s pin to pinprick the image through the plan onto the building material.   You then remove the plan and you go over the pinpricks with a pencil.   I suppose it does have some advantages, but, as yet I cannot find one.  But, let’s not knock it – it is still a method.      The other method is a carbon copy method similar to what typists sometimes use; where you place carbon paper on top of the building material – place your body plan over the top of the carbon paper and you draw around your frames with a pencil and this in turn reproduces the image from the carbon paper onto the building material – and – as they say – THE CHOICE IS YOURS.   

My preferred method is the tracing method – and what I do is photocopy the body plan; pin the photocopy to a piece of plywood ½ inch thick – approx A4 in size for dimensions and this gives me a drawing board type of affair – and I pin the tracing paper over the top.   

The first thing I draw in is the centre line of the frames; followed by the building board line which is in my case ½ inch above the waterline number 17.   If you have a look at the body plan you will notice that there are horizontal lines drawn through the frames and they go from 1 to 17 – now these lines are parallel.

You will notice that waterline number 1 does not begin right at the base of the keel; it actually begins at the plate rebate line.   This is where, on the life sized vessel, the outside steel plating is joined to the keel.   This rebate line, on this particular build, is used throughout the plan as the base line.   So, when you look at the side elevation do not become confused with the line which is drawn underneath the vessel with the numbers on.   It is the 2nd line up from the base of the keel where all of our measurements are taken from.

We get back to what we are doing – we are going to trace our first frame.   We have traced the centre line and we are going to trace the building board line above water line number 17 – DO NOT FORGET the building board line is parallel to all of the waterlines.

So, the next thing is to do – to determine the height of our first frame, which is going to be frame 9 ½ - now as we look at the body plan and I have put 2 scans on to show this – we have running round the top edge of the frames our bulwark line.   This line represents the very top edge of the bulwark which runs right around the vessel.   Below this line we will see another line which runs basically parallel to the bulwark line and this is the deck edge line.   This is the line which represents the very edge of the deck and also represents the height of the deck, where it actually crosses the frame – so if we take frame 9 ½ first to trace – we trace our frame up to the deck edge line.  We then take this height where the frame reaches the deck edge line and transfer this total height from the rebate line over to our centre line.  This gives us our height of the first frame – bear in mind it doesn’t take into account for the camber of the deck.   This gives us a flat deck.     We will come back to the camber later on in the build – I am not going to include cambers onto the frames because it has caused certain confusion and problems in the past – so all of the frames are going to be ‘flat decked’.   We have traced frame 9 off and what I personally do is take the tracing paper off turn it over – reposition it back onto the body plan – realigning the centre line and the building board line along with the body plan line.   I then redraw the frame and in this case it would be frame 9 ½.   So, when you look at the tracing, which you have done, you have traced a full image of the frame albeit that one part of the tracing is on the opposite side of the tracing paper.   I then draw in my support legs which are going to support the frames on the building board.  These normally represent 2 parallel lines, approximately 1 inch apart; which go from the deck of the frame to the building board line.

Now, I have learnt in the past through experience to draw each frame individually on a separate piece of tracing paper, which I did do in this build.  All 14 frames – so at the end of the day I had 14 pieces of tracing paper with full frames drawn on them along with building support legs.

The next stage is, to go to your side elevation plan.  What we require to do is to trace a section of the keel from say….frame 8 all the way up to the full height of the bow.   Don’t forget, we trace the rebate line.   We then need to trace a stern section from say frame 1 ½ all the way around – and all the way up the stern of the vessel the full height – and even tracing the propeller opening.   You may, if you wish, even trace the rudder.   However, on this tracing also trace the centre line of the propeller shaft and also the centre line of the rudder shaft.

[John W E]

We now move on and we require our building material now – which we are going to cut our frames and keel from. As I have already stated, I am using 6mm 5 ply.   

First procedure – pick the long side of the plywood ensure that it is true with a straight edge – the very edge of this plywood.   Then say, 6 inches from one edge of the plywood that is the short edge, put a pencil mark and draw a line half way across the plywood at 90° to the long edge.   What we are actually going to do is draw the frame positions out along the edge of the plywood. 

So, we start off at the mark we have already put and we call that Zero.    We take the distance from our plan for the first frame which is frame ½ and from position 0 we mark this frame position – with a line going at right angles to the long edge.

We carry on until we have marked all of the positions of our frames along the edge of the plywood.  The next stage we do is we take the tracing we have made for the bow of the vessel – we align this tracing up with the frame markings along the edge of the plywood.   So, if you have marked off on your bow from frame 8 – you should align frame 8 on your tracing with frame 8 which you have marked on the plywood and then transfer the bow shape onto the plywood – through the tracing paper.   Repeat this procedure for the stern and don’t forget to mark in the propeller aperture and also the propeller shaft and rudder centre line.  Tip here – when we have finished doing our tracings in pencil on the plywood – go over them with a biro – this prevents the pencil marks fading into the plywood.

Now the next stage I do is to take all the tracings of the frames which I have made and I lay them around and on the plywood so I can achieve the best positions for all of the frames on the plywood., making sure that I don’t overlap the images – when we are happy we have achieved the best positions for all of the frames, we then transfer the images from the tracing paper onto the plywood/building material ensuring that we trace the full image – and not leaving anything off.

This is the advantage of tracing the full frames onto the tracing paper, in the beginning. 

[John W E]

The next stage we move onto is to mark in the centre line of the propeller shaft on our keel drawing which we had drawn previously on our building material.   Along with the centre line we need to draw in the length of the propeller shaft and also the width.   This will give an indication of how much material has to be moved from the keel when we actually fit the propeller shaft.

We need to add a height to our keel; normally I make the keel/s for the majority of my models about ¾ inches high for its length.   As I come towards the bow, starting at say frame 8 ½ I begin to increase in steps – so at frame 8 it will be ¾ inch high at 8½ it will go up to say 1½ high and when it reaches frame 9 it will be 2 inches.

As it reaches frame 9½ it will have gone up say 2½ inches and then as the keel goes beyond frame 9 the height is solid to the deck level.   The same approach is done at the stern of the vessel, beginning roughly at say frame 2 gradually increasing in step; to give continuous increase in heights to the keel.

If you have a look at the photographs, where I have laid the frames and keel out, this will give a better explanation.   We need to move on now then to find out what frames need the centres removing and how much of the centres to remove.    On average, if I have made the keel ¾ inch thick, I must leave the base of the frame of the equivalent thickness, which I did do on all of them.  The only one I left solid was frame 9½ - frames 0 and ½ I cut small ovals in – for to allow access for the steering mechanism of the rudder.   Frames 1 and 1½ need to have the centre line of the propeller shaft also marked in, because the propeller shaft will pass through the base of these frames.   The size of hole that we produce in these frames should be slightly larger than the propeller shaft – to allow for movement when we are in the process of alignment when we are assembling the frames.     Once we have marked out the centres of all the frames, we need then to mark all the notches out in the keel and also in the base of the frames where they locate onto the keel.

The way I did this was I took half the height of the keel which is ⅜ and made the notches ⅜ of an inch deep from the top of the keel.   On the corresponding frames, the notches were ⅜ deep up over from the baseline.   Obviously, certain frames such 8½, 9 and 9½ the depth of the notches correspond with the height of that position on the keel.   Once we are happy and have drawn in all of the notches for the assembly to the keel, we need to draw in the notches for the deck stringer.   On this particular build I manufactured the deck stringers from 2 pieces of Obechi ¼ x ⅛ laminated together to produce a ¼ inch square stringer.  Therefore the notches in the frames have to be drawn out at ¼ inch square at the edge of the deck level.

The next stage in our building is to go and ensure that we have copied onto our building material all of the parts, checked they are correct to our plan & once we are happy we can actually move on to cutting the parts out.    How you cut these out is entirely up to you, there are many ways of cutting materials which have been discussed many a time.  My particular chosen method is to use a fretsaw and this is how I cut all of the frames out and all of the keel, and I cut the frames out in manageable sections first - not cutting to the lines of the frames, then I proceeded to cut the frames out to the lines – leaving about 1/16 clear of the lines.    I do not cut out any notches or the middles out at this stage – I do not cut out the opening for the propeller shaft at the stage.

Once I have all the frames cut out; I move on then to sanding the edges square of the frames, using a flat sanding block.   Happy with sanding the frames, I then move on to sand the keel.   Then, I remove the centres of the frames – and once I have removed the centres I sand the inside of the frames.

I move on now to remove the notches in the frame which locates in the keel.   The first procedure is to remove the notch in the frame and then remove the corresponding notch in the keel – to ensure that it is a neat, but not tight, fit.

When I have completed the sequence of cutting out the notches I move on to removing the material out of the keel which the prop shaft locates in along with the propeller aperture.   

The next stage in the build is to actually fit the propeller shaft in the keel; which is epoxied into the correct position in the keel, ensuring you have approximately ⅛ inch of the end of the propeller shaft sticking into the propeller aperture.

You will also see from the photographs that I have added two small side cheeks which help support the propeller shaft and keep it in line with the keel.    Once the epoxy has set, we can now move on to assembling the frames onto a building board.    The material I normally use for the building board is either ½ - ¾ inch thick stable chip board, which has been checked to ensure it is reasonably level and flat.   The size of the baseboard I try to make 2-3 inches longer than the overall length of the model and 2-3 inches wider than the actual model.

On one side of the building board, I will secure 2 strips of wood roughly 2 inch square soft timber, just to strengthen the building board – and these 2 lengths of timber will be set approximately 2 inches in - down the long side of the building board.   One each side. 

Now before we move on to the actual assembly of the frames there are one or two things we must point out, if you have a look at the photograph of the keel; you will see there is a notch which has been cut out just in front of the propeller shaft – this is marked with 2 arrows.  The reason for this cut out is to facilitate, if needs be, a direct drive motor.   It just gives a bit more clearance and what I did was reduced the overall height of the frame in that area by ¼ of an inch.

The next photograph you will see are the frames which have been ‘arrowed’ and this is where I have added a ‘flat area’ inside of the frame.  This is to accommodate the batteries and it gives them a flat area to lie on.   Now that clears that bit up and we will move on to the assembly.

[John W E]

ASSEMBLY OF THE KEEL AND FRAMES

The first stage is to draw a centre line down the full length down the centre of the building board.  This line is then divided up into equal spaces which each space is equal to the spacings of the frames.  What I normally do, is, lay the keel along the centre line of the building board and transfer off the positions of the frames onto the centre line.  Bearing in mind, from frame 5 going forward the frames face forwards and as from frame 5 facing aft the frames face aft.    (Frame 5 is roughly the centre frame).

Once we have marked off the positions of our frames, we can begin to assemble them onto the building board.   The first thing to do is level the support legs of the frames off – using a flat board with sandpaper stuck to it and this ensures that the centre line of the frame is vertical – best check this with a set-square.   Once I am happy that the frame and the legs are square and vertical, I attach a piece of soft-square timber to the support legs of the frame.  This supporting piece of square timber is roughly the width of the building board and it has 2 holes drilled into it, to which I can secure this timber on the correct position on the building board after I have secured the frame to it.

As I say, I start at frame 5 roughly at the centre and work out to the ends – going one forward/one aft.   With this build you will also notice that frame 0 and frame 2 have to be mounted to the keel first of all, rather than to the building board.  This is because frame 2 has a hole in it to accommodate the prop shaft and also frame 0 slots into the deck beam, which is part of the keel.

So, when we have all of our frames set square and vertical on the building board from frames 0 and 2; which are located on to the keel, we fit the keel.  First of all we do a dry run to test and make sure that the keel fits into the notches of all of the frames; and also that we do not have any frames which are misaligned.   When we are happy with our setup we apply the glue to the notches and then fit the keel permanently.   Whist the glue is drying we secure frames 0 and 2 to the building board.

When the glue has dried on the keel, the next stage is to fair the frames in with a block of wood and sandpaper.    You will see the photograph where I have placed a steel ruler against the edge of the frames to show the angle which is created whilst fairing in and sanding of the frames – towards the bow.

Once we have faired the frames in, the next stage is to fit our deck edge stringers.   Now then, to ease the build of this model, I have incorporated what I like to call ‘false decks’ at the bow and stern.   These are blocks of plywood which have been cut to the correct shape of the deck from frame 0 to the stern.   This is a very tight radius to try and bend timber round, and, this is why we fit these pieces in.    The same procedure is repeated from frame 9½ to the bow.

[John W E]

So, we fit our deck stringers.    These are laminated, on this particular model, out of 2 pieces of Obechi ¼ x ⅛ and this gives us a total ¼ inch thick stringer.   After we have fitted these; we then move on to fitting ¼ inch square Obechi either side of the keel between the frames and this increases the width of the keel so that when we begin to plank it gives the plank more gluing area.  This is sometimes referred to as the garboard strake & when we have finished fitting these either side of the keel, we then move on and fit the side stringers.   On the size of model I am building, the stringers only need to be ¼ inch square.

If you have chosen to double the size of the original plan, giving a model of some 42 inches long, you will find, that you will have to increase the size of stringer from ⅛ to approx ¼ inch and also, the amount of stringers per side you will need to increase from 5 to say approx 7.

How I determined the position of the stringers per side is I took frame 5 again and from the keel to the deck edge I measured this length on the outside of the frame 5.   This length I divided into half; then I went to frame 9 took the overall length of frame 9 from keel to deck stringer and divided that into half.   I did exactly the same at frame 0 at the stern.    I then placed a stringer on all 3 marks; that is the centre mark on 0, frame 5 and frame 9.   I clamped the stringer into position temporarily and with a very sharp pencil marked either side of the stringer where it came into contact with every frame edge.

Once I had marked the stringer position on all of the frames, I removed the stringer and commencing at the centre frame again number 5 – with a      saw I cut the inside of the marks down to a depth of ⅛ and then with the aid of a small file I removed the centre of the notch.   I repeated this procedure on all of the frames; and once I had all the notches cut out, I glued the centre stringer in place.    I did one side first and then I moved over and did the opposite side exactly the same.

I repeated this procedure – total of 10 times.    This gave me 5 stringers per side.

If you have a look at the photographs, you will see how the stringers are set in.

Once all the stringers have been attached to the frame work it is set aside and then allowed to dry.    When the whole frame assembly has dried, we lightly sand down the exterior of the framework and the stringers.

[John W E]

......... pictures of the keel and frame assembly on the building board 

[John W E]

and more pictures of planking support either side of the keel and also fairing the frames in with a sanding block:- 

[John W E]

and .... this is the marking off of positioning of the position of the stringers and actually fitting them....

[John W E]

Now we move on to the planking stage.   For this particular model we are going to diagonally plank – in one piece planks – where the plank runs from the keel all the way around at approximately 45° until it meets the deck stringer.  The material I used is (as I have mentioned before) Lime Strip material 1mm thick and 8mm wide.

Commencing to mark out the location of the first plank – and every boat builder has his own preferred way of planking hulls – some prefer to commence at the bow/stern and then    you get me – I prefer to start in the middle  the reason I commence in the middle is, as we work towards the ends, we try to achieve a full width plank on our last set of planks.  By commencing in the middle then, as we work towards the ends, we can alter the widths of the planks to accommodate our desired finish with a full-width plank.

My procedure …. I roughly pick out the centre of the hull – in this case it is roughly frame numbered 5.

I mark the centre on the keel and with a 45° setsquare I mark off with a pencil on the stringers, this angle.   I then use a scrap piece of planking material bent over the framework the same way as the first plank is going to be placed and I then mark the length of the first plank onto the scrap piece of planking and this is a reference – I cut my first plank to the approximate length leaving approx 10 mm overall length.

I then lay it in the approximate position over the stringers, gently bending it and making sure it is lying flat across the stringers and frames.  Sometimes the plank will not follow the 45° reference marks which you have put on …. This is due to the fact of the radius of the hull.   As long as it is not too far away from your reference marks – it should be okay – i.e. within ½ inch of your reference marks.

When happy with this first plank’s position, we lightly clamp it in place and either side of the plank we mark the stringers with a pencil.   This gives us a reference of where to put the glue – so – once we have removed the plank we apply the glue to the areas between the marks on the stringers.  The first clamp goes on at the keel – followed by the next clamp on the next stringer down.   Making sure that the plank is lying flat on all of the stringers as you proceed down towards the deck stringers clamping.  Wipe off excess glue either side of the plank – because – if the glue hardens, it will prevent you from putting your next plank’s edge up against the edge of your first plank and so on.

Whilst the first plank is drying – turn the hull around and apply the first plank on the opposite side using the same procedure as you did for the first plank on the other side.   Remember that the plank goes in the opposite direction to the plank on the other side – so when you view the two planks from above, they create a V shape.

Allow these two planks to dry thoroughly and when they have, remove the clamps and move on to fit your next plank.   Same procedure but there is no need to mark the plank; you know where the glue goes on the stringers and don’t forget to put glue on the edge of the plank which is going to mate with the plank which is already on the framework.

As this plank is drying and if you have sufficient clamps to allow; you may clamp the next plank on the opposite side of the plank that you glued on first – so in actual fact you have 3 planks on one side and 1 plank on the opposite side – on the hull.  This is a slow process take your time and do not try and rush this job  on average I have only applied 5 planks per side, per day  Rome wasn’t built in a day.

[John W E]

We work towards the bow and stern planking – and about 3-4 days down the line.

We may find that the planks become difficult to bend around the radiuses especially at the stern.  We have several options here; we can place the plank into boiling water and allow the plank to soften.

Or, you could do this which I found worked quite well pull the plank over a piece of 1¼ inch plastic tubing. Gently bending it around the tube.   Be careful now, if you are too rough you will snap the plank says he who had 3 scrap bits of planks.   

If you choose to wet the planks – DON’T FORGET – you must clamp them first without glue, and allow them to dry.   When the plank has dried out sufficiently – apply the glue and then refit the plank.

As we are planking towards the bow and stern planking, we will notice that the planks which we are fitting tend to try and lift off the stringers, even though we are clamping them.   One reason for this is, the radius on the hull, as in from keel to deck radius is changing.   The other thing to consider is that the hull is actually beginning to narrow.   To overcome this problem, we fit, was as known as a spiller plank.  This plank is a tapered plank which corrects the un-evenness of the planking from this plank onwards.  How do we achieve this tapered plank?  The first stage is to cut a normal length plank – and approximately one plank’s width away from your next glued plank on the model, we dry fit this plank – so that it sits level on all of its stringers.   It will not be at the same angle as the rest of the planks – it will be either slightly more/slightly less.   We move this plank towards our last plank which we have glued and then applied to the model & the glue has set, so that one edge of the plank touches, whether it is the top edge or the bottom edge.  Ensuring that the plank we are going to mark our reference marks on is still sitting squarely and flush on all of the stringers, we clamp it to the stringers.

We than get a scrap piece of planking, which is the same width as the planking we are using and place it against the edge of our glued plank.  So that it overlaps our clamped plank.  We mark a reference mark on our clamped plank.   This reference mark is equal to the width of our scrap piece of plank.   We carry on moving down from the keel to our deck edge transferring and marking the width of our plank – until we have a reasonable set of marks – thereupon which we remove our plank which was marked with the marks on and then join these marks up.   This will produce either a tapered/slightly curved line.

We then, with a sharp scalpel, on the waste side of the line that we have drawn on the plank, remove the waste material.    Now, when we offer this plank back onto the model next to our last glued plank, you will see that it sits snuggly on all of the stringers.   When we are happy with the fit, we then glue this plank into place.

As luck would have it, I didn’t take any photographs when I was doing this procedure – on this model – but I do have photographs taken of this procedure during the building of another model which I will include.  We carry on planking as per normal but we will find that this may happen to us once or twice where the planks will not fit snuggly onto the stringers and we may have to repeat the procedure 2-3 times.   This is quite common, also depending on the hull which we are building.    So, as we worked towards the bow, & we are about 8 planks off finishing the hull we want to determine whether the last plank we fit is going to be a full width plank.  The reason being, to fit a little triangle in the corner, which would easily be knocked off is not really acceptable – WE NEED A FULL PLANK TO FINISH WITH – so we do what is known as a good guestimate  we lay sufficient scrap pieces of planking along the hull to find out if we are going to need to thin one or two planks down.

If we do need to thin planks down, it is best to do it now (by thin down I mean reduce the width).   So, we finish planking, we allow the glue on the planking to dry for at least 12 hours.   

When the glue is dry, we then have to sand the hull.  We also have to fill any indentations etc., any gaps with car body filler.   Once we are quite happy we can move on to the next procedure.  However, a warning here and especially a warning for Bluebird – these planks are thin and sanding planks with very coarse sandpaper takes no time to sand through  - have a look at the photographs and you may see a large area towards the stern of filler, this is evidence of heavy-handed sanding.

So take heed  ….. Now for decision time:

[John W E]

............... more pics - you will see in the last pics that the planking does not run all the way to the stern - there is a balsa block glued in place; and when you have finished planking - you sand this balsa block to the shape of the planking and the stern 

[John W E]

We have (in this particular build) a few options with regard to planking.  For those who wish to have a plain hull e.g. with no plating; if you have built a hull the same size as mine 31 inches i.e. to the scale of ⅜ to the foot.  I would recommend giving the hull at least 2 coats of polyester resin with hardener added; with a layer of tissue matt followed by 2 top coats of polyester resin and then sanded to the desired finish for the painting process.  If you have enlarged the original plans to ½ inch to the foot; I would recommend putting another laying of planking on using the same method as described previously, only planking to go 45° in the opposite direction to the first layer of planking.   This new outer layer of planking could then be sanded smooth, filled & may just require a layer of epoxy resin.   The reason for the double diagonal is that it gives the hull added strength for its overall size.   
However, if you are following this build; this is the next procedure are we have sanded the planks, filled them and we now come to fibreglassing the hull on the outside.

I do realise that this topic may be read by anyone at any place around the world, so, any products/items I mention are readily available products in the UK and no doubt, with a bit of web search, you will be able to find equivalent product/s in whichever country you are based.

Polyester resin which I am going to use on the hull is manufactured by a Company by the name of David’s.  This resin comes in small tins approx 500 mls and along with this, you purchase a paste hardener which comes in a foil based tube and the hardener is actually pink in colour.  The tissue matt comes in a plastic pack and it is known as a finishing tissue – it is very lightweight and when you look at it – it does resemble toilet paper.  So, these are the three items we are going to use on our next stage.

The tools we require, if you have them, are, a couple of old paint brushes – say about 1 inch and if you have the privilege to own a small ring roller/washer roller this can become very useful.  The other thing which is useful – but not necessary – is Acetone.  There are substitutes for Acetone which you can purchase or, if you are like me and a bit allergic to the stuff and tend not to use it remember it can affect your skin and chest/breathing severely I don’t bother – I throw my brushes away after using them – purchase the cheaper sort of brushes  .

So, let us commence; first of all we require a nice dry, warm area to work in with a temperature of say 15-20 degrees Celsius – well ventilated remember – and make sure you have adequate room to move around – covering all areas which may be splashed/or if you are like Bluebird promise the Mrs you will fit a new  kitchen 3 years ago – if you are allowed to fibreglass in the kitchen…….still not done – I must remember to make time for that one day………

Anyway, one of the things we have to do is get the hardener to resin ratio pretty right – for the resin to cure and harden correctly.   One of the small aids I do is get a scrap piece of wood and draw out various lengths in centimeters for equivalent mixes.  Now you will see in the photograph what I am referring to – bit of wood with various sizes drawn on and you can see the small plastic tumbler I used - it is marked in mls – I don’t mix resin in this small tumbler – but I do measure the quantity of resin required and I then pour it into a plastic cap from a spray can i.e. polish or something like that.    I then measure out the required hardener and with the brush I am going to use; I scoop this hardener off the bit of wood and mix it thoroughly into the resin.   In normal working conditions, you roughly should get approx 20 mins working time, with this particular resin and hardener mix.

The first procedural stage with the resin is coat the bare hull first off with just pure resin and hardener mix.   This you work well into the planking all of your joints to give a good seal to the planking.  You will note that you will need a less quantity of resin for the basic coating of the hull.

Once we have ensured that the hull is completely covered with an even coating of resin, working the resin all the way down to the deck edge and ensuring that we don’t have too many runs in the resin – we set it aside to harden off.    As a side note – if you find that during working with the resin it begins to ‘go off’ or cure, it is no good now – it must be disregarded.

So the resin on the hull has now been allowed to harden.   We now need to apply the tissue matting – first of all we have to cut the matting to size and on this particular model I cut it into four sections approximately – and the first section was a triangular shape which was for the bow – the second two shapes were from the bow into the centre and then the last was from the centre to the stern.   Now, if you have a look at photographs you will see I have show the overlap of matting I have allowed.  The trick with working with any type of matting is, do not try and fold it upon itself, but always cut the fold and overlap it.   Matting does not like to be folded upon itself – so you need to cut and overlap it.

Now we have cut enough matting – for both sides of the hull – and there should be approximately 8 pieces (4 per side).

Just for reference the overlap I leave on the keel is roughly ¼ inch.   Under normal circumstances, if we had been working with heavy duty chopped strand matting, to calculate the amount of resin we require for the matting is relatively easy to calculate there is normally 2.5 times the weight of the matting.   So if we have 1lb of matting to use, we require 2.5 lb in weight of resin to saturate this matt.

With tissue matt; it is a different scale.   Normally it is about ¾ of the weight to ½ the weight in tissue matting.   However, tissue matting is that light in weight – we very rarely weigh it – unless we are using large quantities – so we use a bit of the old guestimate – and, to give you an idea, I used about 60 ml per side but I didn’t mix the 60 ml all in one go.  I did about 30 ml mix first – and began at the middle and painted the resin onto the hull first – and, working towards the bow, when I had sufficient resin on – I laid the first 2 sections of matting on one side.   I then stippled the resin through the matting; this has the advantage of removing unwanted air bubbles.   If we also have the facility of a small roller, this will aid the removal of air bubbles from the resin and matting mix.

Now we have completed laying the matting on the first half of one side, we move on and do the rear end of the matting.  Same thing, mix your resin with the hardener, apply it to the hull first and then lay your matting on – then stipple the resin through the matting.   Whilst one side is drying, we can move on and do the other side, exactly the same procedure – starting at the front or the back.

Once we have completed the above stage, we must allow the full drying time.  When it is completely dry, and the resin isn’t tacky to touch, we can apply several top coatings of Just Pure resin nothing added /apart from hardener to the resin.   I normally give this 2 coats of resin and then allow it to dry for a good 24 hours to harden off.

[John W E]

These next set of pictures show the tools and materials we require for fibre glassing the hull; also, shows the positions of the over-lap joints in the tissue matt.

[John W E]

Now the resin on the hull has hardened, we come to the next stage which is to sand the hull.   I normally start off with a very coarse wet ‘n dry paper.   For our friends abroad, the wet ‘n dry paper is a sandpaper which can be immersed in water and, as you use it, you wash the area you are working on – with water – and you also wash your sandpaper out in water.   As I say, along with the wet ‘n dry I normally use a nice flat and curved couple of sanding blocks.   I work on the hull until the majority of unevenness and lumps have been removed from the resin.   TAKE CARE – DO NOT RUB TOO HARD – and go all the way through to the wood!!!!!   Once we are happy we move on to a finer grade of wet ‘n dry – I normally work down from a medium grit of 60 to a fine grit of 80.   This is the final stage of the fibreglassing and for those who wish to leave the hull there and move on to actually painting the hull, this is the stage I would normally take it off the building board and fit it onto the building stand.   I haven’t done that for this particular hull, it is remaining on the building board just that little bit longer.   A good tip here is if you have being doing this outside – before you bring it indoors and upset the better half – VACUUM ALL THE DUST OFF  .

So, the next stage is to fit the keel – this is made up from 2mm thick x 5mm Plasticard strips laminated together to a 4 mm x 5mm piece keel.  The first stage is starting at the stern of the vessel where the rudder is, lay the first strip along the length of the keel, glue this into position with Super glue and then take your 2nd length of Plastic strip butt it up to the edge of the first strip that you put on and glue that to the keel but that piece doesn’t go all the way up to the bow – it stops about 4 inches short – so, we need the 2nd layer of Plasticard, but, before we glue this 2nd layer on top we pin with brass pins the first layer in place.  We then glue the 2nd layer over the top.   This 2nd layer stops approx 1-1½ inches at the bow to form a step in the keel.   The rest of the keel section at the bow will be finished off at a later stage. 

Next stage then – we are going to plate this particular hull – well I am doing this.   This assimilates the steel plating.   The plating I am going to use is 10 thou thick Plasticard, glued to the hull – in approximately scale sized plates.

On some plans the draftsman supplies what is known as a Plating Plan  this plan actually gives you the shapes and sizes of particular plates which were on this particular vessel.   We don’t have that facility on this plan, so what we have to do, is, look for photographs of similar vessels.  The photographs will show how the plates run/are applied on the vessel and believe it not finding photographs of this particular vessel was extremely difficult.  Two or three photographs yes when she was out at sea – but on land – very difficult to locate no doubt someone will say they have loads of pictures of this vessel – sod’s law  .   I have found 1-2 photographs of a vessel – much similar to this particular build.

The one thing that we also had to find out was, was this a riveted hull or was it an ‘all-welded hull’ what we have to consider was that the original vessel was built roughly in 1949 by Richards Ironworks Limited in Lowestoft – 1949 – at that time certain practices were being expanded upon and improved upon as in welding.  Also there were a lot of practices which some particular manufacturers wished to hang on to – for certain reasons – and one of those reasons was riveting.   This particular hull could have either been riveted or welded.   But, for this particular scale of model you wouldn’t see much riveting detail on the hull; the other thing was, the way the plates were put on the hull – we have 4 types of plating; obviously we aren’t going to discuss each individual plate system but the system which was used on this particular vessel was called ‘Joggled Plate’.  Basically a joggled plate is 1 plate overlaps the next one but there is a rolled seam in the plate joint, where it overlaps.  So, where do we start and how do we start.

Like everything else in the modelling world – there are more than one way of doing plating.  This is the way I proceeded to do this particular hull.   Out of Plasticard ¼ inch x 1/16 x 7 inches long I made a marker stick which was flexible and would bend round the shape of the hull.   From one edge of the marker stick, I measured out the width of the plates that I was going to use.   I then used this marker to transfer the width of the plate onto the hull from the keel down over to the deck – at 3 or 4 positions along the length of the hull – one both sides of the hull.   With these marks on the hull, I then joined them up using a flexible baton – the flexible baton was a straight piece of planking material which I had left over.   This gave me the width and position of the first row of plates; now, for the width – I worked it out that the plates were roughly between 3 and 4 foot wide x about 9 – 12 foot long.  So, I made my scale plates 4 inches x 1 inch.   I cut the first plates from Plasticard – I glued them to the hull using Superglue – some people cannot use Superglue because of the vapors – I use 2 fans to blow the fumes away – there are new impact glues coming on the market – and I do have one which I have yet to fully try.   There is also a product Evostik impact glue which is said to have good results, but, I have yet to try this.   So, that is the glue we are using – so where do we commence.

I commenced at the middle of the hull for the middle plate butted against the keel long ways on for my first plate.

The 2nd plate to glue on butted up against the keel as well and also butted up against the short edge of the first plate and this 2nd plate was put on, going towards the bow.   The 3rd plate was exactly the same but instead of going towards the bow, I went towards the stern.  So the way the procedure is, one plate going forward towards the bow and one plate going towards the stern.   I plated all the way up to the bow, and when I came to the radius, I used the writing point of an old biro that had ran dry – to indent the radius of the bow into the Plasticard.   This radius which was transferred onto Plasticard was then cut with a craft knife.   It was then dry fitted to ensure that it fitted snuggly into the keel at the bow.  When I was happy I then glued it into position.   The same procedure was done at the stern where the plates meet the propeller aperture.   Once I had one run of plates along one side of the hull, I turned the hull around and repeated the procedure on the opposite side of the hull.

Now for the 2nd row of plates – with my plastic marking stick, I marked off the 2nd row of plates – but, instead of marking them off 2 plates widths, I reduced it by the width of the overlap of the plates – in my case this was about 1/8 of an inch.    I then marked the hull, as before, in several positions at the bow, middle and stern of the vessel and then joined these marks up again and this gave me my 2nd line for the 2nd run of plates.

The first plate I put on – on the 2nd run – one edge must be in approximately the middle of the first plate that I put on- on the first run (I do hope you can understand that).   See the photographs.

[John W E]

................ these photographs show, first of all, the fitting and securing of the plastic keel on the outside of the hull, the 2nd set of photographs show the marking of the position of the first run of plates on either side of the hull

[John W E]

Same procedure for laying the 2nd row of plates as the 1st – we carry on this procedure until we have actually plated the full hull.  We will also notice when we are plating that the plates do in fact taper, as the plates approach the bow and stern.   When I say ‘taper’ I mean the width of the plate will gradually decrease along the length of the plate.   This is normal and may be seen in life size plated vessels.  The last thing is, we must ensure that our last run of plates, overhang our planking.   Once we have finished plate, go over all the seams with poly liquid glue.

The next thing I did was actually construct bilge keels.   Although there are none of these on the drawing, of all the photographs I have seen of fishing vessels they have all had them – so I decided this particular vessel would have bilge keels as well.   They were constructed out of 1mm thick Plasticard and 2mm right angled Evergreen strut.   As you can see on the photographs you will see how and where I positioned them and I glued them onto the hull using liquid poly glue, I didn’t pin them – I am just relying purely on the glue.   I then gave the hull a sanding with very, very fine sand paper.  Just removed the bits of ragged edges off the Plasticard plating – so this should be the finishing stage for the bottom plating and there is a little more plating to do a little later on in the build.

[John W E]

The next stage IS THE GOOD STAGE – REMOVING FROM THE BUILDING BOARD    )and this can be done by either unscrewing the screws which hold the building blocks onto the building board or carefully cutting through the building legs which are mounted on the frames.   Either way, you choose.

We can now build a stand for the model to sit in – whilst we commence the next stages.   This I made from ¾ inch thick plywood.  Just a little side note here – what I normally do is call into my local DIY shop for an off-cut /scrap piece of plywood – which I manage to obtain a lot cheaper than having a piece cut from a full sheet.   

From this plywood we make a decent stand for the model.   For the profile of the stand which the hull sits in, I use the tracings I did for the frames and for this particular one I used the tracings for frames 3 and 7 to do this.   I then lined the inner edges of the supporting frame with sponge rubber.   This gives the hull a nice and secure seating – without any worries of the exterior being damaged.

The next stage in our build is to remove the supporting legs which we have attached onto our frames.  This I normally do with a small razor saw or a broken piece of junior hacksaw blade.    I try to leave on approximately 1/16 inch of the building legs left on top of the frames, so that I may sand off with a sanding block – that is the next procedure.   It is to level all the frames and the sides of the hull – if you look at the photographs; you will see that I am sanding from the outside of the hull in towards the centre of the hull.  Be very careful – don’t forget we have Plasticard plating on the outside (perhaps).   So, we now level the frames plus the outside of the hull; and, at this stage we have to consider do we want to add camber to this deck?   All life size vessels have camber i.e. there is a radius on the deck from side to side.

The way I achieve the camber on this particular hull, is to add Obechi strip of the required thickness to the very tops of the frames.  When the glue has dried, holding these strips to the frames, I then sand them to the correct radius for the profile of the camber.

The next stage of the build is back to mixing polyester resin with hardener of the correct quantity – to coat the entire INSIDE of the hull.  This serves the purpose of sealing the inner planks.

When doing this, make sure you work the resin into all the nooks and crannies – i.e. sides, at the keel, around the stringers, and so forth – anywhere you feel water may lie/lodge make sure you coat that part with a good coating of resin.

Once the resin has dried, we can move on to a new stage of our build.

[John W E]

We now fit a bit of hardware.   There are several schools of thought here:

As far as I can tell, each school has its own correct merits.   Some people prefer to leave fitting of the electric motor for the propulsion of the vessel and also the servos and speed controllers – until later on or the very last thing in the build.   The reason for this (which is a valid reason) you want to know and you can get the motor and associate electrical equipment out without having to dismantle half of the model to achieve this. 

I prefer to fit the motor and certain items beforehand.  The reason being – we can get in and ensure that things are lined up and are working perfectly and if we have to do any major alternations – e.g. to alter the inner framework to take a different set up/ motor etc., and it is far easier to do it at this stage.

So, the first thing I do –

I fit the propeller shaft into the propeller tube  and I hope you remembered to take it out before you did the fibreglassing on the inside.   But, before I fit the propeller shaft I add a little bit of grease and light machine oil (mixed together) and force this with the aid of a syringe into the tube of the propeller shaft.   As for quantity it is a very small amount – I don’t try and pack the prop tube solid with oil or grease.   If the tube is 8½ inches long I only force about 1½ inches of grease mix into the propeller tube.    The thing I do is place the index finger over the exterior hole of the prop tube – then begin to replace the propeller shaft into the tube.    You will find that this will force the grease through the tube, as long as you keep your finger over the end – to seal the hole.

Once the prop shaft emerges from the outside – I put the small brass washer and then the lock nut, onto the prop shaft, and, then return to the inside of the hull where the prop shaft sticks out from the tube and there should be a threaded end of your propeller shaft.   On this end I place the other brass washer and the nut, but, I don’t lock the nut right up – I leave it a few turns slack – enabling me to be able to freely turn the prop shaft.   I then locate and screw on the brass insert, which locates into the plastic universal joint of the coupling – onto the prop shaft.    I screw this all the way on until it butts up to the lock nut on the propeller shaft.   I then lock the small lock nut against the brass insert tightly with the aid of two spanners, ensuring that I have movement both rotary and back and forth of the propeller shaft.   The back and forth movement should be no more than 1/16 of an inch and no less than 1/32 of an inch.

[John W E]

Now for the next stage; this side of modelling sometimes scares a lot of people off the magical mystery of electronics - How many times have we heard – ‘Oh I know nothing about electronics – too complicated’.   Well electronics are as complicated as you wish to make them.

We have now come to the stage where we are going to fit the motor in/propulsion unit.   I suppose we could stick the motor straight into the model, connect it to the propeller shaft and off we go.

Hang on a minute though, we need to do something first  .  We need to fit suppressers.   What are suppressers you may ask and what are they used for.

Let us think - …..  If we go back in time and think of Marconi – Marconi was the guy who gave us all the joy and all the grief – when he sent his first radio signals.  What were they – a spark/flash of electricity and this flash radiates a signal.  To those in the electronics field this is a dirty signal which interferes with any electrical receiving appliances.  These are the basics of all of our communications, radio control model and so forth.

If we wired up our motor to the battery directly and as the motor was running we look through the slots at the back of the motor, we would see there would be arcs and flashes.  (Sparks generating arcs) (Arcs of sparks)  .  This is actually sending ‘dirty’ radio signals out and will interfere electronically with any receiving appliances within the vicinity of it.   You turn the television on and run your electric motor – try watching the picture.  You will see there will be lines etc. and a lot of interference – same with a radio – the interference is coming from your electric motor.

If we have this interference in the model, what is going to be within the same vicinity of the model – our radio control receiver?

So, somehow, we have to get rid of these unwanted signals.   One method is to fit small devices known as capacitors.   They are normally a small round disc with two wire legs sticking out of them.   But, where do we fit them then?   Where do we get them from in the first place and what size do we need.

Well, you can purchase these from the same people who supply the radio speed controllers, switchers, you know there is a guy called Dave – he is the ACTion man – if there is a shop such as Maplins (electronics components shop) do a web search and source out where you wish to purchase your electronic components.

What do we ask for? Polyester Capacitors – 100n – this n after the 100 is pronounced nan or 100 nannies as I once asked for.

Where do we fit these capacitors?    The terminals on the back of the motor that we connect the wires from our battery to; the capacitors are connected there and to the casing of the electric motor.   How do we go about this and what do we require?

Solder
Hefty 25 watt or larger watt soldering iron
Flux
Emery paper/sand paper/fine file

First stage with this :

If we look at the back of the motor where the terminals are and have the terminals so one is at 3 o’clock and one at 9 o’clock at 12 o’clock on the motor casing we want to clean a small area there – with either the emery paper or the file.

Next we smear a tiny little bit of flux over the area we have just cleaned with a file; and make sure we don’t stick our fingers back over this cleaned area.   We then mount the motor securely in either a vice or some sort of support on the work bench – to prevent the motor from rolling all over the place.

With the aid of the electric soldering iron (remember to switch it on)    we heat the area that we have cleaned and applied the flux too on the electric motor casing – with the soldering iron.  We then apply solder to the heated area.   The solder should melt and run freely.  If it doesn’t then it means that there is not enough heat there yet.   When we have a small area covered with solder approx 1/8 of an inch, we remove the solder and the iron and allow it to cool slightly.    The next stage is to take one of our 3 capacitors; these are not polarized they can be fitted anywhere around.    In fact it doesn’t matter which leg is soldered to the motor casing or which leg is soldered to the motor terminal.   What I like to do now is use some small insulation off either telephone or bell wire – to cover the legs of the capacitor.  We only apply enough insulation so that there is at least ¼ inch of free leg endings of the wires sticking out of the end of the insulation.

We take one leg of the capacitor; and, we attach this to the area that we have applied the solder too on the casing – by re-heating the solder and allowing the leg to become attached to the fluid solder.

The other end of the capacitor / opposite leg is now soldered to the motor terminal – either the positive one or the negative one (sometimes the positive connection on the motor is marked with a red dot beside it).  Now we repeat this and the only difference is – we have already tinned the place on the top of the motor where the last connection was made and, so, therefore we just solder the leg of the new capacitor over the top of the previous soldered leg.

We then solder the opposite leg of the capacitor, as we said, to the negative terminal of the motor and don’t forget PUT YOUR INSULATION ON.

Now for the 3rd capacitor, which is of the same capacitance value as the 2 already soldered to the motor.  This 3rd capacitor is soldered between the 2 motor terminals; the terminals which we have already soldered the other capacitors too.  Now this capacitor is the one which must have insulation covering its legs, we don’t want a short between the motor terminal and the body.  Whilst we have the soldering iron out, we may as well solder the 2 power wires to the motor.  What size wire? We will be asking, well, the most we can expect (on a bad day  ) is for this motor to require 15-20 amps in what they call a surge and anything above that we are going to have a fuse to take care of it.   

So, if we say, we will use 15 amp wiring; it would be well on the safe side. 

As for the actual wire or cable, I tend to use the flexible household stuff, the 3 core mains cable which we can purchase from the DIY shop.   What I normally do, is the outer plastic sheathing – I strip that off.  This reveals the 3 individual cables and this is the cable which I use.

So, first of all, what I normally do is cut the cable to the desired length – roughly twice as long as we are going to require – say some nine inches for this particular model.  Then I remove the insulation from the first ¼ inch of one end of the wire; and tin this, with a soldering iron and solder.

I then solder the wire to the motor terminals; so we have done the little bit of electrics now and we go on to fitting the motor into the actual model.

Now, this motor is going to drive through an Olympic belt drive Gear Box so we must assemble this part first.  One tip with these gear boxes, if you look you will see the 2 slots for allowing the bolts to pass through and secure the motor to the gear box framework.  I open these 2 slots up with a file so that the screw/bolt will pass through really freely.   The next thing I do, is, disregard the 3mm Philips head screw which is supplied with the gear box, and replace these screws with 3mm diameter Allenhead bolts.

The next thing I do is place a larger washer over the 3mm bolts when I am securing the motor to the gearbox.  The reason for the larger diameter washer is it prevents the head being drawn into the soft plastic of the gearbox.

The first procedure then is to assemble the small cog on the end of the motor first – followed by placing the belt over the larger cog and then mounting the motor into place ensuring that the drive belt isn’t over tight.   It is always wise to connect the motor up to the battery; and give the motor a spin under power to ensure that the belt doesn’t run off the small pulley.   If it does, you may have to have a slight adjustment by adding very small pieces of packing between the gearbox frame and the motor mating face.

So that takes care of the motor gearbox assembly and the next thing we must do is actually make the base plate which actually holds the motor gear box assembly into the model.  (Motor bed plate).    This is made from ¼ plywood and if you have a look at the photograph, you can see it has a slot in the middle – this is to facilitate the main drive shaft of the gearbox, as this is slightly proud.

The next thing is the rear support which is a V shape and which locates onto the keel and also underneath the bed plate and helps support.   So, we have these 3 bits of assembly – we secure the motor gear box to the bed plate and we must align it with the propeller shaft.

To do this, we get the mating brass bush; which fits the end of the gear box drive shaft and I do believe this is a ¼ unf thread or possibly metric.   So, we locate the brass insert on the end of the shaft, locking it up to the lock nut.   The next stage is to align the propeller and gearbox up, now I have a piece of brass tubing which actually fits over neatly, the splines of the brass inserts.  It is the same length as the plastic coupling; so, I push this brass aligner onto the coupling on the propeller shaft and also mate the gearbox coupling bush to it.  This brings the gearbox and propeller shaft in line with each other.

So, the next stage then, is to ensure that the plywood motor bed sits correctly on the frames and also on the V support block.  What we do to ensure is – if the frame in the model are a little too high – we can sand a little bit off or if there is a little gap we can put a little piece of plywood as a packing piece in.

Before we secure everything down, the propeller shaft and the motor must turn freely.    One of the tips which I learned many years ago was, if you connect a 1 ½ volt pencil-sized battery up to the motor and this turns the motor and propeller shaft freely, the alignment is near enough spot on.  So, this is what I did, when I was really happy with it, I epoxied the plywood bed plate to the framework and the V support, I also epoxied the V support to the keel.   I used the 5 minute epoxy.   Whilst the epoxy was setting, I kept the motor running using the 1 ½ volt battery.   

I then removed the brass alignment piece from between the 2 brass inserts and then replaced it with the plastic universal coupling.   Then I connected the motor up to the 6 volt battery and allowed the motor and gearbox run for about quarter of an hour to bed-in – checking that there were no ‘HOT’ areas on the motor, gearbox or prop shaft.

Also, during this RUNNING IN period – I clipped in an Amp meter – just to check the amps.   Started off at 2 amps and rapidly dropped down to 1 ½ - 1 amp.   As everything bedding in. 

[John W E]

and these 2 pics show the capacitors fitted to the rear of the main motor;

[John W E]

Now for the next stage – We have to have something to steer our model with.   We have her moving along, but – now to turn her left and right (port and starboard)

We now come to one of those times – where we need to make a decision – on this particular plan, on close inspection, you will see that the rudder post comes all the way through the main deck.   Whereupon there is a doubled armed tiller; connected to the end of each tiller arm there is a chain which runs alongside the superstructure up to the bridge to where it connects up to the steering wheel.   The really clever ones amongst us – could actually connect a servo to the ends of the chain – so the actual servo operates the chains which operate the rudder – just like on the real vessel.   I have seen some really lovely models built this way and perform really well.   

For this particular model though, I am going to try and keep it – SIMPLE AND BASIC – so, I am going to assimilate the chains and tiller later on in the build and actually put the true tiller linkage below the decks.  So, this is the procedure which I have adopted.

First of all, go back to the plans, and, scrutinize the area of the rudder.   We will see that the rudder post – this is the bit which goes through the hull – actually enters the hull a fraction aft of frame zero.   So, this is where our rudder tube has got to be placed.   From the plan & on our model then, we can locate frame zero - & - we will see that just aft of frame zero we have fitted 2 plywood false decks or cheek pieces to aid us with our build.  We must remove part of this structure along with the top half of frame zero.

What I did was I got a pair of compasses and I marked a semi-circle which was slightly larger in radius than the total length of a servo operating arm.   This semi-circle don’t forget – its centre is in the centre of frame zero.

The next stage then is to remove this semi-circle along with some of the balsa wood material underneath.   To do this we use a process called ‘chain drilling’ – it is roughly that you drill a series of holes inside the semi-circle to a set depth & then cut between the drilled holes with a scalpel and then remove the inner area.

To prevent us from drilling down and right through the bottom of your hull; make a very expensive jig up  very complicated  piece of wood with a hole drilled through it the same size as I was going to drill.  What I did was drill through the scrap bit of wood first, place it over the drill so it is hard up against the drill chuck jaws; then measured the distance between the end of the drill and piece of wood – this distance (in my case) was just under ¾ of an inch – and this gave me an adequate safety margin between the outside of the hull and the depth I was working at.

So, I proceeded to chain-drill the set of holes inside the semi-circle, using a ¼ drill and my Dremel drill – I joined the holes up with the aid of a scalpel and removed some of the plywood and the balsa wood underneath.  I then cleaned this area up, using a small sanding drum attachment, which Dremel do.

The next stage now is to drill a hole through the bottom of the hull in the correct place to take the rudder tube.  Now, I normally drill through first, with a small pilot drill and using a watchmaker’s drill.  The reason I prefer using a hand drill is that you have more control of it – i.e. you can ensure that it is vertical in all directions.  Because, if you do make a mistake drilling the hole true, it is a difficult job to put it right.

So, when we have drilled through with a pilot drill, I normally slide a piece of brass rod (the same diameter as the drill I have used to drill the pilot hole) through the hole to ensure that it is running ‘true’ with the rudder post.

When I am happy with the above; I drill through with the same size drill as I am going to use for my rudder tube.

Now we come to the next stage in the building of the rudder.

We require is the following for the first stage of the rudder build:-

Some plywood to make the rudder blade with

An adequate length of 1/8 brass rod

Some 1/8 brass tubing

Some more brass tubing of the diameter which slips over the outside of the 1/8 brass tube, neatly, to form a sleeve

We also need some 1/16 brass rod


The Tools we require:

Dremel/equivalent drill machine

1/16 drill bit; small round jeweller’s file

Small centre pop

Small hammer

25 watt electric soldering iron

Some solder; flux; epoxy resin & hardener;

Small file and rule; also, if we can get our hands on one – a Modeller’s pipe cutter; if not, we will have to do this with a small razor saw.

The first stage:   We measure through the hole we have drilled through our hull, to get the measurement from the outside of the hull to the top of the frame or keel on the inside of the hull.   To this measurement we must add approximately ¼ inch – in my case, on this particular model, it worked out at about 1 ⅛ of an inch; so, the largest diameter tube is the one we use first.   We cut this to 1 ⅛ of an inch in length; then we remove the burrs from the inside.   We do this with the aid of a round file.

We then take the smaller diameter brass tube and we cut 2 lengths off – roughly about ⅜ of an inch long.  We remove the burrs from the inside and the outside of these pieces.   Clean the outside of the small tubes and apply a small amount of flux.  Try to avoid handling the outside of these tubes from now on.

So…we place one piece of small tube inside the larger diameter tube, so there is roughly about 1/16 of an inch sticking out.   Then, with the soldering iron, which has been connected and switched on, we heat this area of the tube.  We then apply solder to the end, to allow it to run right around the tube – therefore soldering the inner tube to the outer tube.

When it has cooled; we turn it around and repeat the procedure on the opposite end, soldering the last piece of small tube in place – inside the larger tube.

Now – when you think about it – there is now a gap inside the larger tube – where the 2 smaller tubes don’t meet – the reason for this is – it will become a grease trap to prevent water from entering the hull.   

We clean it all up, removing all of the flux and set it to one side.

That is our rudder tube made.

We now move on to produce our rudder and rudder post.  We require our drawing here to either trace from or copy from – the shape of the rudder – onto a suitable piece of plywood.   I used 1/8 thick plywood – some of you may prefer to use a thicker plywood and sand it down later on – it is entirely up to you.

So I have the shape of the rudder plate and now I must make the post.

If we drop the rudder post through the hole we have drilled in the hull; so that the post hangs below the keel of the model by about 1/8 of an inch.   Then, on the inside, mark off the length – just below where the deck is – then remove the post from the hull and cut this length – remembering to remove the burrs – and now if we offer the rudder post to the long flat edge of the rudder plate, so that there is 1/8 inch sticking below the bottom of the rudder – then – proceed to mark onto the brass post the centre of the length of the rudder plate.  Either side of this centre mark which you have marked on the rudder post – about ¾ inch – put 2 more marks.  These marks are where there are going to be 3 pins fastened to the rudder post.  What I normally do here, is hold the rudder post in a vice, flat with the jaws of the vice and file 3 small flats – where the marks are. (The ones I have put on the rudder post).   In this flattened area I centre pop the centre – so I now have 3 centre pops perfectly in line down the centre of the rudder post.

The next stage is to very carefully drill through the rudder post, using a 1/16 drill and the Dremel electric drill.   Make sure that these holes are true.

The next stage is then to cut 3 lengths of 1/16 brass bar; roughly the length of the brass bar must be half the width of the rudder plate.   Once we have cut the brass bar to the right lengths – we place the 3 pieces into the holes we have drilled in the rudder post – so that they are all sticking out in the same direction flush with the back of the rudder post.

To the area which the 1/16 brass rod goes through the 1/8 brass post; we apply some flux – and solder it in place.  We do this with all three pins.

When it has cooled, we clean up the back end of the rudder post, the opposite end to where the 1/16 brass pins stick through.

What we must do now is; place our rudder plate in a vice so that the long edge is sticking vertical and is level with the vice jaws.   We slide our rudder post level with the edge of the rudder plate, ensuring that there is 1/8 of the rudder post sticking below the rudder plate.   We mark off the pin locations on the edge of the rudder plate; where we marked on the edge, we now drill with a 1/16 drill to the same depth as the length as our brass pins – ensure that the drill doesn’t come through the side of the rudder plate.   So, we have drilled 3 holes to the correct depth – we give a trial fit of the rudder plate to the rudder post – by locating the 1/16 brass pins into the holes which we have just drilled.

When we are happy with this fit, and, the rudder plate is in line with the rudder post, vertically – we can now epoxy the rudder post in place.   The way we do this, we mix a small amount of epoxy and, with a toothpick, force the epoxy into the 1/16 holes which we have drilled in the edge of the rudder plate and smear a bit of epoxy along the longer edge.   We then fit/locate the pins into the holes and push truly home so that the rudder plate is truly home against the rudder post.

What we may have to do (as I did) is temporarily clamp the rudder post into position – because of forcing the pins into the holes we are forcing the epoxy out  and it has a piston effect – i.e. it tries to force the pins back out – so, we must hold it in place whilst the epoxy sets.

When the epoxy has set, we dress the rudder up, using sand paper and file – and what I did was  - I gently tapered the rudder plate, to an aerofoil section, but I didn’t take the trailing edge of the rudder to a fine point – I left it blunted by about 1/16.

So, that is the rudder and rudder post both made. 

The next stage is to epoxy the rudder tube into the hull; a tip here – when epoxying tubes/rudder tube into the hull – after we have cleaned the outside of the tube and roughed it up a little – very carefully apply a small amount of grease inside the tube – without getting any grease whatsoever on the outside.  Then, mix our quantity of epoxy required with a cocktail stick – apply the epoxy on the inside of the hole in the hull.  Very carefully then making sure that it is the end with the grease in, goes through the hole first, push our rudder tube into position.   Making sure there is at least 1/8 of an inch sticking out of the bottom of the hull.    We may have to hold this into position, by applying a small amount of cellotape to the outside of the hull; this prevents the rudder tube falling all the way through.   The grease on the inside of the tube prevents any epoxy entering the tube and therefore bunging it up.  So, that is the rudder tube fixed into the hull.   

Now, there is one last thing which we need to do, before this part of the rudder is complete and that is to make the bottom bearing into which the bottom part of the rudder post locates.   I made this from some 1/8 x ¼ strip flat brass.  The total length of the bottom bearing was approximately 1 ¼ inches long.   

So, to proceed making the bottom bearing, first off, lay the piece of flat brass on a secure surface, so that the broad edge face of the brass is facing upwards.   Divide the width which is ¼ inch into two equal parts and draw a centre line parallel with one of the edges of the brass.  Take one edge (doesn’t matter which edge you take) and put a mark ¼ inch from that edge on the centre line.  Then centre pop the mark you have made.    Another ¼ inch on the centre line put another pop mark, and, then approximately ½ inch from your last centre pop mark put another mark on the centre line; and centre pop that.  So, in actual fact we have 3 centre pops all in a line, down the centre line.   

The first centre pop mark which is ¼ inch from the edge – we drill a hole here of 1/8 diameter.  The next two marks we mark with the drill 1/32 of inch holes.  We need a flat file now; and, the edge we have drilled the 1/8 inch hole nearest too, we radius it, with the file.   This is basically the set up for the bottom bearing.  We remove all of the burrs and the best way I have found of removing the burrs, is, to take a drill larger than the 1/8 hole – and by hand twist the drill into the hole and this will remove the burrs – then do the same again on the smaller hole.

[John W E]

and these pics show the assembly of the rudder fittings....