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[Nick-R]

Since returning to the hobby in my dotage, I have built a few kits - Aeronaut Queen was a relatively easy start followed by a Billings Nordkap then a SLEC Perkasa and I have recently completed a Billings Smit Rotterdam.  I found all of these to be high quality kits with excellent laser cutting and good quality materials.


My latest project is a Bruma motor sailor from Mantua models.  I bought this from a supplier in Italy via EBay at a substantial discount on UK prices even after paying the import duty.  I have confess to being a little disappointed with the kit because:

• The fit of laser cut parts is a bit too slack.  Slotting frames to the keel, for example, allowed frames to rattle about to maybe 10/15 degrees out of true.  To be fair, longitudinal stiffeners help pull everything square but it would be easy to end up with a banana shaped keel!  I have a Mantua keel clamp which I normally use for tapering planks but have used it in this case to ensure the keel stays straight.  You need to use a glue with decent gap filling qualities and in my case, I have also used epoxy putty for additional stiffening.   I have not had this issue with the other kits mentioned above and indeed am more used easing joints to get a good fit.
• The false deck is not a great fit on to the assembled keel/frames and sanding the frames enough to get zero gap between the deck and hull planking leaves the stanchions formed by the top of the frames perilously thin,  to the extent that I have left a bit of a gap in some places which I will fill with insert pieces.
• Apropos the problem above, the instructions call for the false deck to be planked before planking the hull.  The boat has scuppers formed by a gap between the planking at the top of the hull and planking on the frame stanchions.  This means that it is important that the planked deck to be flush with the plank at the top of the hull.  I have therefore taken the approach of fitting the top hull plank, taking care to ensure it is flush after deck planking as required.  It also highlights the gaps between false deck and planking that require to be filled.
• Some of the materials are not great.  Sanding the frames to accommodate planking, for example, has exposed voids in the intermediate layers within the ply.   Some of the planks have what appears to be knots or maybe crush marks which fracture when you attempt to bend it.  To be fair, the good planks respond well to soaking and bending with my trusty 1960s soldering iron.
• Instructions are not great, even the downloaded version.  The model is double planked but instead of having a rabbit at bow and stern, the outer planks butt up to the corresponding plank on the other side of the hull.  The planking pattern also is different from previous plank on frame models I have built and I have learned more about how to approach it from a build log I found online.  I am not at that stage yet but envisage some effort to get a good straight finish on the bow rake and stern!

I am sure the model will end up fine, but it is not for beginners!

[harrin]

Thanks for sharing this. I've considered this for my next build    Please post photos of your progress, I'm interested.

[Martin (Admin)]

 
Seen the Mantua Models Bruma at several shows over the years.... Can be made into a beautiful model !

[Nick-R]

I will take some photos and attempt upload.  I have say, I have recently had difficulty with that but it might have been down to the issue in a thread below?.


The model is twin prop but is set up for a single motor driving both shafts via a gearbox.  Mantua supply the motor and gearbox but I have heard it is noisy in operation and anyway, I prefer independent control of both props in a twin shaft boat. 


This gives another problem as the Mantua setup has the motor positioned aft of the gearbox i.e. with the drive shaft facing forwards and the body of the motor between the prop shafts.  Fitting two 385 motors plus couplings takes up much of the tray intended for batteries/ radio gear as well as covering up the intended Mantua site for the steering servo.  Sorting all this takes a bit of imagination and I am currently looking at mounting the servo between the shafts and locating the motor escs in shelves fixed to frames at hull sides.  RX can be similarly accommodated.  That will leave enough room for a couple of 2s 5ah lipos..


The supplied props are plastic two blade items of very coarse looking pitch. They are both right handed whereas ideally they should contra rotate. To be honest, they do not look of great quality and I will replace them with a pair of handed brass 3 blades probably 35mm.

[Nick-R]

So here are a few photos showing:

• Gap deliberately left as stanchions becoming too thin!
• Poor quality plywood
• Knot or crush mark on plank which simply breaks if you try to bend it
• Epoxy putty strengthening and starting gap infil from below
• My trusty plank bending kit and bent plank ready to install

[Nick-R]

So not getting photo upload!  Tried as attachments and also add image to post with no joy.  I have optimised all photos and they are all less than 60k!  Hmm?


Ignore!  Success!

[Big Ada]

 


  Photos are showing now.


  Len.

[Nick-R]

A wee update on progress:

• Twin motors have been installed instead of the Bruma single motor driving the props via a gearbox.  The Bruma motor is mounted aft of the gearbox so that its drive shaft faces forward.  My installation requires the motors forward of the shafts and uses a good bit of the room Mantua show being used for batteries and radio gear.  I have mounted the steering servo between the motors and will put the escs between the motors and hull side with RX somewhere yet to be determined.
• I have completed the decking.  As mentioned in my post above the top hull plank should be flush with the planked deck and so I fitted the top plank before deck planking and definitely think it is the way to go.  It also identified the gaps between false deck and hull to be dealt with.
• Fitting the planks involves putting the first plank flush with the stanchions sticking up from the frames but with those planks meeting the hull just forward of frame two at the bow and butting up to the forward facing side of frame 11 at the stern. The port and starboard planks should meet the hull at exactly the same distance from the stem.  Taking care to get this millimetre correct means that these set the pattern and getting the rest placed symmetrically is much easier.
• The completed decking has now been protected by two coats of sanding sealer and two coats of clear satin varnish, rubbing down between coats.
• Hull planking has started.  It is a somewhat tricky planking pattern and I am debating whether to fix the shafts and plank round them or remove them, plank and the drill through?  Hmm?  I notice that the supplied planks are different wood from those on some build logs I have viewed - different reddish colour.  They are quite brittle and will break rather than bend quite easily.  I have found the trick is to soak the apply heat to bend a little bit, soak again the bend a wee bit more.  Repeat until required bend is achieved.  Bending does get easier after a couple of soak/heat/bend cycles

[Nick-R]

So first planking is almost complete and ready for second planking.  I made extensive use of my bulldog clip clamps which worked well but the second layer will need to be pinned/nailed.  The supplied planks have to be handled carefully and require a good soak and application of heat to get them to bend without breaking.  It is important to bend them sufficiently that they fit easily without strain.


A lot of tapering is required also and I debated whether to remove the prop shafts or leave them in situ and plank around them.  In the end, I planked around them.  The area around the shafts is quite tricky and needs a bit of patience.


I have sanded the hull and applied some filler just to smooth the surface for second planking.  I use B & Q?s own brand filler which I have found quite good over a few models and it is relatively porous so that yellow wood glue adheres to it easily.  For final surfaces, it accepts epoxy and hardens well - I generally use several coats of EzeKote, rubbing down between coats.

[Martin (Admin)]

 
Great idea installing two motors!   

[Nick-R]

So planking complete and rubbing down started.  This was my first double planked build and it does make for a strong hull.  The trick as always with a planked build is to ensure that the planks are bent to shape so that fitting/gluing them requires the minimum of pinning in place.  The supplied planks are a little on the brittle side so care is required when bending them but, to be fair, there are plenty in the kit.


When I started the second layer of planking, I used brass nails but now wish I had not as extracting them just increases the need for filler.  Better to just pin planks in place until the glue goes off.


The instructions suggests fairing in the prop shafts using scraps of planking but I have used Milliput epoxy putty to create a fairing instead.  Once mixed this product gives plenty of working time before it goes off and can be sanded/filed once setk.  Wet fingers/tools helps working it into a smooth finish.  It has the dual advantage of sealing gaps where the shafts pass through the hull.


Just on the prop shafts, I chose to leave them in place and fit planks around them which I thought would be easier than drilling holes after planking!


On to my clumsy fingers friend, the tin of filler next!

[roycv]

All good stuff and I am following with interest.  My Bruma kit is still in its box, although I have been gathering additional parts, I agree 2 motors is best.  I have a commercial dual esc with mixer incorporated which I bought on ebay.

  The seller said he did not understand how to use it, but that is now solved.  I do not think the unit is currently on sale any more.  New props and shafts and I use the brass part of Hugo couplings with a thick walled tubing to connect, nice and silent and gives constant velocity.
Is the heat from the plastic part of the soldering iron enough to form curves on planking wood, or do you use the hot tip?
Cheers
Roy

[Nick-R]

Re bending planks, I use my venerable 1960s soldering iron (I have a modern soldering station courtesy of Lidl for actual soldering!) as shown in an earlier post to this thread above.  I do not use the tip part of the iron but the chrome body between the handle and the tip.  This is not quite as hot as the tip and generally does not harm the soaked planks.  It can though scorch the wood if you are trying to get an actual bend at a point on the plank rather than a gentle curve along its length.


Some parts do require such a bend notably on the bottom of the hull around the prop tube support where the hull slopes up towards the canoe stern. I see from other build logs that others have tackled this by cutting short the plank at the frame with the prop tube support and using a separate short plank from there to the stern.  Also on second planking the final approx 1.5?cm fit towards the bow needs a fairly acute angle.  I found that leaving a bit of length on the plank when bending it and then trimming to size after it is bent easiest.

[roycv]

Hi Nick thanks for you explanatory notes, will file the info and use later.
Regards
Roy

[Nick-R]

Bruma


So started work on the cabin structure as a little break from rubbing down and filling.  Also started looking at finishing and what needs to be done once the hull is complete by way of forward planning.  So here?s a few more comments:


1) I opened some of the fittings packs for the first time and I was not best impressed with the quality of the supplied castings - see pictures below.  Most of the items are easily identifiable but there are what looks like bottle screws for tensioning rigging but where these are to be used is not obvious either in the plan or written instructions.  Most of them are bent and have a lot of flash needing to be cleaned up.  I will need to think about these later in the build.


2) There are little posts that sit on top of the bollards formed by the top of the frames which support a teak railing.  These need to be drilled to accept a bit of 1mm steel rod to fix them to the top of the frame bollards.  I got the little drilling jig pictured from Temu for ?11 (having see it advertised by another vendor on Facebook for ?40+).  Not sure how I would have tackled this without out it!


3) The cabin structure fits into the aperture on the deck and the bottom of the cabin sides parts are not curved to follow the sheer of the deck.  This leaves a small visible gap between the deck and the cabin which I will tackle by glueing a strip of left over 1mm square mahogany strip from the decking around the bottom perimeter of the cabin.
Re this structure, I prefer to have a coaming round the aperture that the cabin fits over as that makes for a more watertight structure.  Also, coming back to the quality of materials, the ply used for these parts were stained using the supplied walnut stain.  This has resulted in what looks like water marks due to variations in the veneers used in the plywood.  Fortunately, in my case, the parts pictured are the roofs and will be painted white anyway and where it has happened on the cabin sides that will be varnished I have been able to make sure they were mostly on the inside and not the exterior.
In fairness , the fit of the cabin parts is far better than the keel/frames with all joints being tight and well aligned.


4) finally, I need to drill a 3mm hole into the 4.5mm thick rudder to accept the rudder post in exactly the right spot made a bit more complicated because the edge to be drill is sloping to accommodate the shape of the hull.  I do not have a drill press and I scratching my head a bit on how to do this - maybe starting with a small pilot hole and gradually enlarging to the 3mm required?

[Nick-R]

So just out of paint shop! 

• B & Q?s own brand filler, lots of rubbing down and re-filling
• Five coats of Eze-Kote rubbed down between each
• Five or six passes of Halfords rattle can white primer
• Five or six passes of Halfords rattle can gloss white
• Five or six passes of Halfords rattle can red metal primer which gives a good representation of red antifouling.

I also obtained a selection of different width masking tape from Temu which seemed like a very good (cheap) deal. It looks very similar to Tamiya masking tape but unfortunately does not perform nearly as well.  I guess you get what you pay for and I had to resort to my Tamiya tape to get the required reliable adhesion!

So it?s onwards to cabin and deck fittings followed by masts and rigging

[Nick-R]

Update on progress!  Since my last post the following has happened:


1) I have completed the cabin structure with just detail to add.  This was relatively straightforward with die cut parts being a good fit giving square assembly.  The roofs are quite thick ply and decent clamps are required to hold them bent to the required curvature while glue sets.  For me the wheelhouse roof, having been glued with yellow wood glue popped at one side on releasing clamps after over 12 hours.  Some two part epoxy carefully worked into the gap and re-clamped did the business.


2) I have added the gunnel caps which required pinning to the tops of the frames and trimming to fit at bow and stern.  These were varnished before final assembly and I used a rattle can of clear varnish currently ?3.99 from Lidl.  Works well and relatively quick drying.


3) Lots of little detail parts assembled/varnished or painted.  The windlass assembly holes are too large for the supplied white metal windlass drums and needed bits of wood shaped to fit the inside of the assembly with the correct hole size drilled in them.  I might look at some commercial fittings for things like cabin vents, nav lights, etc as these will probably look better than making them from scraps of wood per the instructions.


4) the rubbing strakes have been prepared including drilling holes for pins.  Bearing in mind that these are varnished to be stuck to the painted hull, I and using some pins and two part epoxy - carefully!


5) I have used my Heath Robinson method to taper the masts and spars which involves clamping a drill to my desk, inserting each dowel into the chuck then using strips of sandpaper - many strips of sandpaper and several hours to get the acceptable taper.   The main masts as supplied are pretty well the correct length but the bottom part is below decks so any chuck marks are hidden.  The dowels for the spars are large enough to allow any chuck marks to be trimmed off.  I have then used a couple of coats of Ronseal antique pine satin.


6) the kit supplies two gauges of brass wire 1mm and 1.5mm.  Both are tightly rolled and getting them pulled straight may be problematic for many people.  With previous models, have managed that by stretching the wire between two sets of pliers but that technique does not even look at it, at least not with my elderly strength.   I eventually achieved a result by clamping one end with a mole wrench , standing on it then stretching it upwards with both hands on a pair large pliers. 

[Nick-R]

So a lot of work. for what does not seem like a lot of progress.


1) the teak capping to the plank tops has been installed. The four laser cut pieces to do this were pretty accurate with just a bit of careful trimming to ensure they butt up to each other at bow and stern.  The whole laser cut sheet these were attached to was stained at the outset of the build with the supplied stain. - a powder you mix with water.  It was then given a few cots of clear varnish. To be honest, if starting again I would have opted for a different, lighter stain.


2) the stern rail, again teak capped and mounted on supplied wooden balustrades.  Each balustrade had to be drilled top and bottom to accommodate a short length of 1mm brass rod at the bottom and 0.8mm top for brass nails.  A bit fiddly but not as difficult as I first imagined.


3) the forward brass railing was created from the coiled brass rod supplied with the kit.  Straightening that was a bit of a challenge involving locking one end in a mole wrench, standing on the wrench and pulling up as hard as my elderly bones will allow the other end caught in a pair of pliers.   With a suitable length straightened the pulpit was formed by finding a suitably radiused shape - in my case a screwdriver handle to form the forward pulpit then roughly curving the long lengths to fit the hull shape.


4) the supplied propellers are 35mm two blade with a very coarse pitch and both the same hand and therefore not contra rotating.  I decided to replace these with brass three blades.  I also found that I had mounted the prop tubes too far into the hull and so did not have clearance for 35mm props so sourced a pair of 30mm three blades, one right handed and one left handed.


5) I started to seriously address the radio installation.  I have opted for the same system I have used before on a Smit Rotterdam to get full independent motor control.  Each motor has its own esc and battery with the red (power supply) cable to the receiver connector disconnected on one esc as only one esc should power the receiver.  This gives forward/stop/reverse on vertical movement on right and left sticks.  I have opted for a couple of cheap 20amp Chinese escs (?6 a throw) but these seem to work ok.  I will mount these and the receiver in my normal way via Velcro.   I will wait until any ballast is sorted out first before mounting them.


I centrally mounted the steering servo but found that the rudder tube is quite close to the aft bulkhead and so the tiller has to be mounted about 45 degrees from parallel to the bulkhead.  The supplied tiller I found was too short and came close to being at 90 degrees to the bulkhead and in danger of locking up at hard over.  I therefore made a larger tiller from hard plastic which copes with the servo movement easily.


Finally, I have gone for 2x 2s 3ah Li-ion batteries on offer from Amazon complete with charger for 14 quid!  I anticipate that the 385 motors will not draw much more than 2 amps so these should give a comfortable hour sailing time.


Next step is a bath test to check for leaks and also what ballast is required.


6 I have started preparing for mounting the masts, yards and rigging.  Cast metal jack screws are supplied and these are attached to the deck by brass eyelets.  The quality of the castings is poor and the was a lot of flash which required trimming off.  Also, all of the holes required to be drilled out to accept the .8mm eyelets.  As I write, I will have to enlarge the holes at the other end to accept 1mm diameter rope.


On a related topic, the mainmast boom is very close to the removable cabin.   Once the running rigging is in place removing the cabin for access to machinery might be difficult so some thought will be required.  Maybe raising the position of the booms is required?


7 Finally, I have spent quite a lot of time building and painting small parts.


Onwards and upwards!

[Nick-R]

A wee adjunct!  First flotation test - about an hour in the bath and boat is bone dry!  She has a very slight list to starboard and needs some ballast, especially towards the stern.  I use sheet lead offcuts as these can be cut easily to shape and bent to follow the hull curvature.  One wee advantage of having taken the stern tubes about 1cm too far into the hull is that the inside end appears to be just above the waterline so hopefully no leakage from there!


Photos do highlight some touching up needed on white paint job!

[Nick-R]

Cautionary tale!  Next flotation test with some added ballast.  The ballast took the ends of the propshafts from being slightly above the waterline to slightly below and given qualifying for a rookie mistake award and not greasing the propshafts, flooding ensued.  Fortunately I had not left the boat and was experimenting with some additional ballast here and there when I noticed the leak and ended the session.
Despite coating the interior planking with EzeKote I noticed that some wood appeared to have soaked up the water so further treatment is required - Mrs Robinson's hairdryer has its uses!  Anyone got any tips for getting epoxy resin into awkward spots under fore and aft decks not conducive to brushing?

[JimG]

If you use a surfacing resin like Aeropoxy this is thin enough that it can be poured into the space and by moving the hull around it will run into the places you want. Adding a little bit of isopropanol will thin it down even further and it should soak into any joins or splits.
Jim

[Nick-R]

I poured some EzeKote into a small container then sucked it into a syringe and used that to squirt it into the tricky places.  Appears to have worked OK!

[roycv]

Hi all I agree, I have just worked on a decorative model to get it seaworthy.  It is the 3rd. I have worked on and they always leak.  So best to work on the inside first then the outside.  This allows for any water leaks penetrating dry wood.
Roy

[Nick-R]

So getting to final stages:


1) the radio installation has been finalised.  Same as my Smit Rotterdam, two Escs controlling each motor independently with forward/stop/reverse on the vertical plane of the left and right sticks on my tx.  Tested and working well in the bath and looks like my choice of 385 motors and two 3000mah Li-ion batteries, one on each motor will produce ample power and a decent scale speed.


The batteries came from Amazon with a dinky wee charger which worked via the balance charge leads on the batteries.  Toyed with installing the usb powered charger in the boat hooked to a usb socket under the stern gear hatch but ultimately decided against that due to safety concerns re leaving batteries in the boat.  I considered that as removing the cabin structure once the rigging is installed might be tricky, especially at pond side!


2) The stern rigging brace seemed to me to be somewhat fragile with mast rigging attaching to it, braced only by a thread attached to an eyelet in the stern.  I have opted to attach the brace to the stern by a length of 1mm brass rod which adds considerable extra strength.


3) Various small sub assemblies have been fixed to their place on the deck.  Re fittings, the supplied anchors do not fit due to the bracing 4mm ply which is part of the skeleton of the boat.  I may end up cutting the stock off to get the to fit flush.  Likewise, the hawse pipe holes supplied - brass collets - do not fit the supplied chain.  Fortunately, I had some smaller diameter chain from another model on hand.


4) I do not have a vertical drill press and thought carefully about drilling the holes to fit the mast cross trees at right angles to the mast.  My Heath Robinson solution was to clamp the mast in my Mantua planking clamp and then use a right angled container lid with a vertical line drawn on it to guide my drill.   Once the shorter cross tree was fitted, the same technique was used for the larger cross tree, using the shorter one to ensure the the mast was clamped so that the second cross tree was parallel to the first.


Because of anticipated difficulties in removing the cabin once fully rigged, I mounted the mainmast spar slightly higher than shown on the plan.


Stepping the masts was relatively straightforward.  They were epoxied to the slots in the keel and where they pass through the deck.  Once the epoxy had set, the joint to the keel was reinforced with Milliput epoxy putty.


5). The bottle screws securing the mast brace lines are of pretty poor quality soft metal casting.  There was a fair amount of flash that required removing.  Most were bent and all of the holes required to be drilled out to accommodate the brass fixing eyelets and standing rigging thread.


6) the supplied tiny pulleys are wood and required the holes to be drilled out to 1mm to accommodate the supplied running rigging thread


I am now about to start rigging which is the last lap and my least confident.  The deck has been drilled for rigging fittings. Further flotation tests in the bath showed about 1 kilo of sheet lead was required. 


Onwards and upwards!

[Nick-R]

So pretty well complete and ready for sea (pond) trials.  There are a few details to add - anchors, flagstaff, masthead lights, etc.


I hate rigging.  I have what the doc calls a benign tremble - basically shaky hands - and so find threading tiny holes in pulleys and eyelets tricky and time consuming.  I have no idea how guys do projects like sailing ships and admire their skill.


Overall I found this quite a challenging build and the quality of materials in the kit a little disappointing but, in fairness, there is plenty of everything - I have nearly enough planks left over to build another boat!  It does also build to quite an attractive model - nice enough that Mrs Robinson (the boss!) has deigned to having it on display in our front hall!  I will be handling dusting though!  Need to invest in one these dust blowers!


Off to an important appointment with the Scotland national in the colonies - Boston - now for a couple of weeks so maiden voyage will have to wait!