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Author Topic: Ketch Build  (Read 6470 times)

Jack D

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Ketch Build
« on: August 24, 2015, 10:28:05 PM »

So, not satisfied by having a fleet of models in need of finishing or refit, I've decided to get another hull. Over the last couple of years sailing with the Portsmouth Model Boat Display Team I've caught the tall ships bug. Ships from the age of sail do look fantastic both in and out of the water so I decided I was going to have a go. The club has a fort with a (horizontally, if not vertically!) static ketch moored alongside. At just 31" long, I thought that it was a perfect size to dip my toes into the world of scale sailing ships. Also, being a ketch, it should be fairly straightforwards to have her sailing under wind alone with the sails operational, something which would be much more difficult for the novice builder with a fully square rigged galleon.

The hull is commercially available, the West Country Trading Ketch by Orion Mouldings. It's a very sturdy little hull and looks very nice, especially the 'copper bottom' detailing. The one gripe I have is that it appears there's a gel coat on the inside of the hull, which although looking very nice does need a lot of attacking with a grinder if you want anything to stick to it.

Without further ado, here's what the hull looks like when you get it.


The piece of wood next to it is going to be a drop keel which will hopefully stop the boat crabbing sideways or going belly up when she's sailing. It will have lead fibreglassed in on the bottom edge as the models' ballast.

The hull comes with a good plan in 1:1 scale, although I'm not following it, I'm more or less winging it at the moment and we'll see what we end up with (the current plan is something that can be rapidly converted from a trading ship to a bomb ketch and visa versa). While everything will likely end in tears somewhere down the line, not working to any particular plan does feel quite freeing and allows me to think creatively.



I'm using the club's built up hull as a reference, as seen below.

The masts will be in the same place, as will the deck and mine will also be a topsail schooner with any luck. the stand I built also takes a lot of inspiration from here.

I built my stand out of some old scrapped wood which turned out to be lovely multi-ply which is hard as nails along with some thick wooden dowels for handles. The cut of the stand allows for a drop keep and for some padding to be added to the stand once painting is finished.



Also quite conveniently, the large pieces cut from the main frames are big enough to act as mast crossbeams in the hull, so two were cut to size and positioned as they are on the reference model.

They're only dry fitted at the moment- those along with the other deck supports will be going on after the motor, steerage and keel are in place.

At this point the model starts to move along different lines to the static reference model. A section was cut from the bottom of the hull to fit a propeller and a gap for a propshaft was drilled out. I've fitted a plastic 35mm prop which has been painted to look like brass. when I remember my camera again and don't have to rely on my phone, I will take a better photo.


To go with this prop and shaft is the motor. I've decided to go brushless, my reasoning being that it should be more efficient, so longer run times when the wind is unfavourable (and hopefully allowing it to do the Chichester Canal run on one battery under favourable conditions) and the ability to fight the considerable amount of sail to get into and hold position in a display. I've gone with a Turnigy 750Kv motor which I will be running at 7.5V which will hopefully give not too much of a silly top speed. Unless the keel does its' job very well I can see disasters if the ship gets into fast electric speeds. The original plan for mounting the motor was to have a baseplate siliconed to the bottom of the ship with a wooden block screwed to it which in turn has the supplied aircraft mounting screwed in place. As it turned out, the shaft was too short and the hull hadn't widened out enough to fit this kind of assembly. However, after a bit of rooting around a 380 sized motor mount turned up which fits like a glove. Still with not enough room, the plan was hatched to mount the motor upside down. As you can see below there are the two oak crossbeams bolted to the motor mount, which allows the whole lot to be removed if the motor needs to be looked at or replaced, etc.


The Assembly was dry fitted along with the propshaft and the motor and shaft were subsequently bonded in at the same time. Note the bare patches of hull which have been rubbed down to provide a rougher contact point. These initial areas were far too small and a much larger area was ground down.



The whole lot was bonded in using Fibre putty of the kind used to make structural repairs to anything fibreglass. It is green and very strong, so hopefully it's going nowhere. The somewhat large superfluous hole in the stern was plugged with this stuff at the same time as trying to hold the propshaft in place. After the green goop had gone off, some epoxy resin was layered over in the shaft area and heated to run into any gaps and help make everything watertight. After this even more epoxy was added, mixed with sawdust, to try and help.



Next up the ESC will be installed, most likely on the topside of the beams holding the motor if there will be sufficient clearance with the deck etc. The keel fin will also be installed, using copper pipes running up almost to deck level running threading up from the keel through the boat which will then be secured with bolts to hold it on while in use. That, alongside the rudder tube will the the only through-hull penetrations which will need waterproofing. Once all the holes have been made and sealed it will be the time for the first in tank test to make sure nothing leaks. It will be far easier to solve now rather than when the deck is on.
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tigertiger

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Re: Ketch Build
« Reply #1 on: August 25, 2015, 01:26:22 AM »

Its nice to see a ketch :-)) , I have only seen one model ketch before.
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Jack D

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Re: Ketch Build
« Reply #2 on: September 04, 2015, 09:37:03 PM »

A little more work I managed to get in last night.

First off, a much better photo of the prop. This just needs a coat of Matt varnish to make it look natural- hopefully the shine of the metallic particles in the paint (trapped under the hard gloss varnish) will still give a dull shine.



Next up is the keel. I have 200mm * 8mm studding with the end bolts sawn off fitted to the keel with fibre paste. These were placed into slots cut into the keel and held in place with superglue. To ensure a good contact area, sawdust was sprinkled on the bolts in situ then a lot of liquid glue was added. The sawdust helps bridge the gaps in the parts and it works really well (just remember the activator before the glue runs too much and you have a horrendous mess!). Obviously superglue is entirely unsuitable for the final join, but is more than adequate for holding it all in place while the fibre paste goes off- the last thing you want is wonky keel bolts! In a similar vein, the brass tubes which will take the threading into the ship will only be fixed in place after the keel is constructed, to make sure it all fits really nicely. You can see here that the holes have already been made for them.

I'm hoping that the keel at this size will prevent crabbing- the surface area of the keel is similar to that of my Comtesse and this ketch will have a similar or even smaller sail area, so it should be fine (fingers crossed!). There will be ply layered on each side of this keel with grain running perpendicular to the centre board. This should prevent the possibility of the keel breaking along the grain if it takes a big hit (say from a submerged rock), which would take most of the ship's ballast with it (to be added later). The ketch would probably go belly up within seconds if this were to happen so it does need to be addressed.
In addition to the two bolts here, there will also be one small locator and reinforcing stainless steel 'pin' at the stern to spread any stresses out.

Here's the hole for the rudder shaft, which should be the last through-hull hole at or below the waterline. Unfortunately it's a little large, as are the holes for the keel. This is likely due to a mixture of inexperience of working with hulls on my part and over enthusiasm with the new reamer.


Finally, we have a photo of the battery tray. Measured to take a 8.4v 3.8Ah NiMh stick. In all likelyhood this is far too powerful and will likely be dropped down to 7.5v or even 6v if I can get away with it. The tray is an odd shape so it can fit into the hull at a slant. This means that the amount of room taken up along the length of the ship is reduced, allowing the keel bolts to have access via the same hatch and not interfere with the masts. The battery will sit between the two bolts. Also, the esc for the brushless motor has got a bec so there will only need to be one battery. Hopefully while idle the esc and motor won't draw much power at all, so I can get a very healthy amount of time out under sail.



That's all for today, hopefully I'll be able to spend some decent time in the workshop again soon!
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dreadnought72

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Re: Ketch Build
« Reply #3 on: September 05, 2015, 12:10:50 AM »

Thanks for clear explanations! Good luck with the build!

Andy, nearly finished with another ketch.
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Jack D

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Re: Ketch Build
« Reply #4 on: September 12, 2015, 05:24:30 PM »

Thanks for clear explanations! Good luck with the build!

Andy, nearly finished with another ketch.

I personally like making clear explanations because I'm a beginner into this really and I figure if I point out all the little things I learn or take note of it might help another beginner who stumbles on the thread. If I make a mistake that one person avoids after reading my write ups, I'll consider it a success.


Only a little more done on the ketch this week- I've bonded in the battery tray, the brass tubing for the keel and the rudder tube. I've also cut some bracers to go over the keel runs which will be bonded in at the same level as the deck supports, so they'll be able to pull double duty. Unfortunately it takes too long for the green fibre paste to cure in order for me to do it all in one day. Again, I attacked the inner layer of gel coat on the mould with an angle grinder before bonding anything.

Note here the difference between the fibre paste around the brass and battery tray compared to the motor mount. The more smoothed effect on the motor mount is achieved by smoothing the fibre paste with a finger. Wearing gloves for it though won't work because they get stuck and snagged on the paste. It's also worth noting that the paste and its' hardening agent are irritants so if you have sensitive skin I wouldn't reccommend it. However, it does make a nicer finish and seriously cuts down the amount of sanding needed after it sets.



Here is the rudder tube being bonded in, with the rudder in place and clamped to act as a guide. Also note the clamps on the keel holding it in line- there is another keel clamp at the bow end of the keel and a jack of conveniently sized wood supporting the middle. this holds everything in place nicely, so in the unlikely event that the brass tubes start to 'wander' while the paste sets, the keel will keep them in place well enough.

There are a couple of things to note here- first is that the rudder shown is not the finished product, there will be a large amount of wood or plastic cladding this brass construction to form a nice (and useable for a sailing ship) rudder. This brass here is just silver soldered together to provide a very sturdy attachment point (thanks to Unbuiltnautilus). The second point of note is the length of the brass tubing installed. They are all far too ling and will be cut back. The keel runs will end at deck level (with a cargo hatch/gun pit stuff raised above deck level to cover the nuts) and the rudder tube will be at a suitable point above the waterline (tbc). It's my opinion that it is relatively straightforward to cut down the tubing once it has been installed, especially using a small rotary cutter, whereas adding length to tubing which was made to short when bonded in is much more difficult.
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roycv

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Re: Ketch Build
« Reply #5 on: September 12, 2015, 06:42:21 PM »

Hi enjoying the build.
As far as props go I have several sailing boats with 'lunch time assistance' (props) I usually go for as coarse a pitch as possible and 2 bladed, this has the lesser resistance to travelling through the water when stationary.  You also do not need much power either just a few watts.
A prop is always useful when you need a little extra when tacking.
regards Roy
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Jack D

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Re: Ketch Build
« Reply #6 on: September 13, 2015, 05:51:02 PM »

Hi enjoying the build.
As far as props go I have several sailing boats with 'lunch time assistance' (props) I usually go for as coarse a pitch as possible and 2 bladed, this has the lesser resistance to travelling through the water when stationary.  You also do not need much power either just a few watts.
A prop is always useful when you need a little extra when tacking.
regards Roy


That would normally be my 'go to' for a primarily wind powered ship too. However, in this case, I have to think about maneuvering in displays, like the one seen here: https://youtu.be/QwFs5NVKVWo?t=4m49s
In this case I would potentially have to ignore wind conditions entirely and force the boat to sail unnaturally. We've also had a lot of issues with the larger galleons not having enough power to fight the wind at all and being blown ashore or into floating obstacles and getting stuck- something I wish to avoid at all costs so more power than is needed I don't mind.

Additionally, my local water is home to pedal boats and when I sail there without lots of other modellers they can become a problem. In one notable incident a group of yobs tried to run over one of my Comtesses and due to the wind conditions I could either tack under the paddles of the rogue boat or smash into the concrete side at great speed. I haven't fully repaired the damage to the prow yet. In that case the ability to suddenly put out five knots or more and put myself on the other side of the lake would be very useful.
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roycv

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Re: Ketch Build
« Reply #7 on: September 13, 2015, 06:23:12 PM »

Hi Jack, good points, I do not have to fight the paddle boats or manoevre with the 'navy'.
regards Roy
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Z750Jay

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Re: Ketch Build
« Reply #8 on: December 22, 2015, 03:22:35 PM »

Jack is right in having that ability to stop being a graceful sailing boat and go full Clarkson to get out of trouble coming in handy. With the general public normally pedeling the pedeows why chatting on there mobiles blissfully unaware where they are heading plus the in ability of some of our fellow club mates to navigate on the pond without hitting something it can make for an interesting time.
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Ianlind

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Re: Ketch Build
« Reply #9 on: January 01, 2016, 05:18:13 AM »

G'day Jack,


I was just killing a bit of time and found your thread, and it's interesting that you have chosen the same motor that I have reluctantly fitted in my tug, Albert. I'm a brushed motor fan from way back, and have used them successfully for over 30 years, but this time around I was coerced into going brushless, and just happened to choose the 2836/11 750kv as you have.
This motor screams, and I mean noisy, as are all brushless, but at 6volts it's percolating at 4500rpm, so your little ketch will be on the plane in seconds! Make sure the prop is locked on tight!
Albert hasn't hit the water yet, but I'm thinking we might be going back to brushed, as they are quiet and I've got boxes of them in stock. I use 12V fan motors and also 12v electric aerial motors depending on the size required. And they are/were cheap years back when I collected them from wrecked cars. Generally I belt drive to keep the motor revs up and prop speed down.


Check out Alberts build log under Working Vessels. He's about 24" long and over 12" wide, and I'm thinking this motor will still be a bit of overkill, spinning a 50mm x 4 blade Tug prop, direct drive!
Regards,
Ian
 
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davidm1945

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Re: Ketch Build
« Reply #10 on: January 01, 2016, 04:34:57 PM »


This motor screams, and I mean noisy, as are all brushless,
Regards,
Ian

If it screams as badly as that I suggest that you check the ballraces. I bought a Turnigy brushless, brand new, and it sounded like a soul in torment. I stripped it down, bought new quality bearings from ebay, fitted them and now it is quieter than any of my brushed motors. Folks at the pond side comment on how quiet the boat is. Worth a check!

Dave.
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triumphjon

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Re: Ketch Build
« Reply #11 on: January 18, 2016, 08:13:03 AM »

id increase the area of your rudder if i were you , scale sail dont respond very well with a true scale rudder . are you planing just the single battery ? the coastal barge i use on on the canal has two sail servos , wired direct to a 6v 4ah battery before the rx is powered , its motor is fed from a 12v 7 ah battery , with the red rx wire disconnected from the esc .
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Jack D

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Re: Ketch Build
« Reply #12 on: March 20, 2016, 01:05:20 PM »

I'm planning on having the motor control on the right hand stick and I might mechanically lock the stick to prevent it from ever going too fast, if I can't program the TX. Hopefully it should still run relatively efficiently, I wanted to get decent sailing times out of it (which has taken a major blow, more on that later). It didn't seem too screamy when I fired it up but we'll see when it gets tested properly, I might have to change the ballraces as suggested (not looking forwards to extracting the motor any more!).

The rudder will be absolutely enormous, I'm looking at plans in the scale sailing models book for semi hidden points to put a rudder extension on. It will be at least as deep as the keel when finished and fairly long at the bottom too. I'll probably be running one battery, there isn't room for two. It will likely be a 7.5v 3500Ma racing pack. Not too lumpy so I should be able to carry a couple of spares for the canal if needed. I'm also tempted to buy a cheap radio with telemetry for this model which will tell me about the state of the on board power- I've had a go with the FlySky models which are very good and very reasonably priced, especially compared to my planet T7.
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Jack D

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Re: Ketch Build
« Reply #13 on: March 21, 2016, 12:16:38 AM »

OK, time for a build update. While I haven't posted on any of my other build threads due to lack of progression, I have actually been putting a large number of hours into this ketch. The reason I haven't been posting is because these build posts take quite a while to compile and I don't have much time, working six days a week and building the ketch and everything else on the seventh...

Well, that's only a half truth. The main reason I haven't posted anything is because I'm slightly very ashamed of how badly everything went after the last post. Pretty much everything I put in went in crooked and it looks fairly horrendous. For experienced builders with low tolerance to really wonky angles, this is your warning to look away now. For everyone else, feel free to point and laugh.


Here's a picture of the first set of beams going into the hull. They're being fixed with the now ubiquitous green fibre paste. The multi ply pieces are going to be the beds for the masts, while the other two pieces support the drop keel run. All of the beams are at deck level so will all pull double duty. It's worth noting that the drop keel bolts will be beneath the raised main hatch. To keep everything level I've clamped every beam to straight lengths of wood to set.



Here are the first set of crossbeams in. Note the holes in the mast supports for the mast pins to fit in. If I were to build another I would only drill those holes once in the boat. Both beams went in at a bad angle so neither of those holes were in the right place and needed to be later filled and re bored. The photo was also taken at an unusual angle intentionally to hide just how messed up the angles of everything is in there- none of the beams are straight and are off by up to twenty degrees or more...



Putting more beams in, using the existing ones as a guide for the correct height, all clamped on wood again. These new beams are oak- the forward beams are to outline the bow hatch and provide some strength up front and the stern is to mount the rudder servo (the aft deck will be raised somewhat as was common on trading ketches of the late nineteenth century). These new beams actually went in straight, by some miracle. But they draw the eye uncomfortably to everything else *not* being put in properly.



This photo contains the new beams emplaced. Also, the hull has got wet for the first time (other than cleaning release agent and dust from the hull when it first arrived). I only realised afterwards that I hadn't done any waterproofing to the keel at this stage so immersion in water was probably a terrible idea which may have contributed to the later minor warping along its' length (luckily correctable by a couple of stainless steel guide pins). I was a little surprised that the keel without ballast was heavy enough to force the wood down and not try to roll the boat.

The main reason for putting in the tank was to check for leaks around the propshaft, rudder and keel runs. Everything stayed dry inside so this was a resounding success. Also, it was found that it will take a few pounds of weight from this stage to get a correct waterline. I would like most of that weight to be in the form of ballast at the bottom of the keel though so all construction is to be kept as light as reasonably possible from here on out.



The aft oak beam has a slot cut out of it and holes for screws to fix the rudder servo in place. Although at the time of the photo there was no second beam in place, one was fitted as detailed later. Without the notch in this beam the servo would be impossible to remove- given the strain this poor thing will have to put up with replacing at some point is a near certainty.



Here the servo is installed. There will be a different arm put on the servo, but I just kept the old aircraft fitting on. I have a great many of these servos which I inherited from my grandad and his large scale aircraft building. As you can see one end is just hanging in the air at the moment, which will be fixed very shortly.


As you can see, another oak beam has been screwed into the servo. This beam will now be bonded to the hull with fibreglass paste using the servo itself as a guide to hold it in place. I find this is a very simple way to install two beams to support a servo like this. Later you will see the sail winch installed in a similar manner, affixed initially to a single beam. The mounting of the winch and rudder are slightly different. The winch is closer to the bottom of the hull, which enables two lengths of studding to be fixed with bolts through the fixing points on the servo and run to the bottom of the hull where they are bonded in. In the case of the rudder the drop was too large and could seriously interfere with (major) propshaft issues if they arise in the future.
You can also see the gel coat has been sanded away where I intend to put down the fibreglass paste.



You can see the keel bolts protruding out of this clamped monstrosity, which goes some way to explaining what this is. The keel has had a thin length of wood bonded to each side with the grain running perpendicular to the main keel beam, which should stop any catastrophic splitting which would lose the craft all of its' buoyancy in one fell swoop. In essence I'm making a very primitive plywood. The skinning pieces are being bonded with epoxy and are held to the table between two blocks of wood and a lot of clamps. There is paper between the keel 'sandwich' and the blocks keeping it all straight, to prevent epoxy 'ooze' from gluing the whole lot together and causing a real nightmare.


Here's the almost finished product of the keel. You can see where epoxy has been squeezed out and was caught by the paper. This was all cleaned off fairly easily with a blade. Also note the stainless guiding pin for the stern in place.



Here's the bottom of the two masts. They're 12mm dowel which will taper towards the top. They have the stainless pins in to locate into the deck. The holes in the deck are sleeved with brass tubes to prevent wear and tear on the wood beneath.


Here you can see the start of the rest of the deck guides go in in. They are simple balsa rods spotted in with superglue and fixed with epoxy to the hull. They're going to provide an attachment area for the deck and should make it easier to waterproof once the deck is on. Here you can see ANOTHER pretty major mistake that led to a fairly major redesign. If you look at the lines at the bow you can see that the guide follows a straight line instead of the lines of the hull like an actual deck should (the one time I actually manage to fit a straight line...).


Here you can see my solution to the previous photo's issue. Instead of rip out the original stuff and start again, which could well involve removing most if not all of the deck lines, I instead elected to make a raised fore deck. Unusual perhaps for small traders, even moreso to have the mainmast on said foredeck, but it will make for a striking model when complete I think. I'm also somewhat glad that I'm not actually following a plan here. The crossbeam the sail support will run through is balsa with a block of hardwood filling the gap between the main support underneath. There is also a brass rod running all of the way through all three pieces of wood, so most of the strain should in theory be taken up by the more solid wood (that which isn't taken by the rigging stays). It's worth noting that all of the wood in the ship was doped with two layers at this stage to make them waterproof. The last thing I'll want is salt water or sea air intrusion causing the whole lot to rot inside out over a few years' time. I'm hoping this will last a while before needing a rebuild.


Firstly, note the now redundant balsa guides for the hatch between the oak beams- where the deck ended up being raised these serve no function and will be cut out of the ship later. Also, note the pile of dust collecting in the bows. That was at least half an inch deep. It was all thoroughly cleaned with a combination of brush and hoover before the deck goes on.
Finally, perhaps most obviously in the middle of the picture is the sail winch. The end not fixed here was secured by brass threading and bolts bonded to the bottom of the hull.
 This is a Graupner Regatta Evolution.

This winch is complete and utter overkill in every sense of the word (it was only used because industrial action in the Phillipines is causing the preferred winch to have severe supply issues). This winch is intended for models twice the size and as such I will be more than happy to put every scrap of sail that I can on the ketch to get it moving at a decent clip (and pray that I don't overdo it and cause it to roll over in too high wind). There should be no issues with stalling trying to pull the sails in against the wind whatsoever.
This power does however come at a price. This winch IDLES at half an amp and draws three and a half to four amps in operation. This is likely going to be the single biggest power drain on the boat- the brushless motor pulls very little when idle and should be rarely used. As a result sailing times will be restricted to only a couple of hours, something of a far cry to my Comtesses which will literally sail for days on a single set of four AA batteries.



Finally fitting the deck, made of 1/16th ply with the main hatches already cut in it. The batteries are holding the ply level. In reality I did this one section at a time and this is just an artistic set up of what it would have looked like had I been insane enough to do at once. With five minute epoxy the bonding only took one afternoon. Shaping the decks however took significantly longer. With ply this size is is easiest to shape with a craft knife and a metal ruler rather than trying to put it though something like a bandsaw. Note the overhanging stern deck. The overhang was filed back with permagrit after it had set thoroughly. It was a lot easier than trying to shape the ply perfectly, especially since it was sitting flush to the top of the boat with nothing to guide it, unlike the other two pieces.



Scarily, she's starting to look like a boat! the gaps between decks will be filled with two layers of 1/16th ply. The deck will be planked with walnut- I'm not sure if I'll be using oils or stain on the deck yet. I will likely have one or two planks of a lighter colour to represent repairs as well. The planking will add strength to the deck, which at the moment is insufficient. I chose the very thin ply deck because it is very light, especially a consideration since there will be planking layered on top. The masts here are only the lower sections. There will be upper sections added to extend the masts by a significant amount, this will be very tall.


Starting to put combings in around the main hatches. These first pieces were cut from the sections removed from the decks to make the hatches- very little adjustment to length needed! the combing will be two layers of this ply for added strength. You can see that I've added thin strips of balsa under the hatch openings to provide a gluing area for the combings.

That finally brings you up to date with the build so far. More will come soon(TM).
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Captain fizz

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Re: Ketch Build
« Reply #14 on: March 21, 2016, 11:21:32 AM »

That was a marathon post Jack, well done mate!
Well, she is coming on. At one stage, I did wonder why you were filling the bath with a hose until I realised it wasn't actually in a bathroom doh!
Will the sheet winch control both main and mizzen boom?
Looking forward to the next instalment.


Simon
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Jack D

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Re: Ketch Build
« Reply #15 on: March 21, 2016, 09:30:25 PM »

The float test was unplanned- the test tank was being used to check another model and I decided to take the chance to make sure the hull was watertight on the ketch. It's actually two bathtubs joined together which is useful, given that in Portsmouth we're spoiled rotten by Canoe Lake we can make our models as large as we want (in fact smaller stuff can get swamped pretty easily) so they don't fit in the bath at home all that well!

The working plan is for the winch to run everything, the main, mizzen, jib, topsail and top yard (via the mizzen). It's perhaps a little ambitious and there could be some issues turning though. Not sure if I could apply the same principles from a Bermuda yacht, albeit less efficiently. I'm just thinking for mizzen control I'd put in an arm but I don't know how I'd control it without using my old 40meg graupner set which I can't find any more receivers for.

I also just discovered a ton of other photos on my phone, I knew there were some missing. They're the demonstration photos of 'things I learned while building', so they could be useful for beginners. I'll put them up at some point.
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triumphjon

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Re: Ketch Build
« Reply #16 on: March 22, 2016, 08:52:03 PM »

hi jack  ,  my thames barge uses two hitec sail arm servos to control her sails , the main and top is from one while the fore sails control from the second  , because ive got my spektrum dx7  tx ive managed to set each servo to a seperate channel but im also able to mix the two channels & operate both sails from a single stick ! your welcome to pop over to see how it operates
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Jack D

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Re: Ketch Build
« Reply #17 on: March 07, 2017, 08:20:14 PM »

So, almost a year later and how much progress has there been? Well, not as much as there should have been honestly. Spending a day working on this a week with competent skills should have taken six months, maybe a little more tinkering with rigging and running stuff. Unfortunately life isn't that kind and I stupidly volunteered my weekends to go work with birds of prey then decided to do a masters degree where I can't get access to a workshop (so I'm also slowly going insane but ho hum!), so I haven't had as much time as I would have liked. On the other hand, there has been progress so I'll keep you all updated.

First up, I missed some steps in my last post, I took some photos with my phone and they got missed out, but if a brand new beginner stumbles on this they show things which might be useful to take note of.
So, for an embarrassingly large amount of the build I didn't have any reference to where the centre line of the ship was and I was doing a lot of it by eye or measuring across the beam of the ship in various places. It didn't work very well. In the end I relented and tied a piece of string to the rudder tube (the mid point of the stern) and glued the other end under tension to the middle of the bowsprit, like so:


Now, this also allows you to notice other things, like the fact that the hull is actually asymmetrical. It isn't much, to the untrained eye like me I didn't notice it until this point, but it is fairly significant. I'm relatively confident that this had a large part to play in why the support beams got so badly messed up- I was shaping them symmetrically and they wouldn't fit true in the hull because each side is a slightly different shape. What this will do to performance in the water I don't know, but since I'm (hoping) not going to be a speed boat it shouldn't be too bad.

Following up is a result of the centreline being found and why you shouldn't mark out a hole for a mast before the strut is in the boat- the hole is out of position by at least half an inch. If this happens it isn't the end of the world, you can drill a new hole and fill the old one in. To fill the old hole I shaved a peg of wood approximately the size of the hole and secured it with epoxy mixed with sawdust, so there shouldn't be any major structural flaws from the superfluous hole.


Secondly before I laid the deck guides down I noticed that the stern wasn't level and needed correcting. This isn't a jab at the hull manufacturer, the hull overall was in really good shape and needed no filing of excess anywhere else so I just got complacent and didn't check as well as I could. It was only a few millimetres difference.



To rectify the true flat level was marked on (how we found the true level I can't remember any more, but it involved exotic tools called rulers and skill far beyond mine to line it up and draw round a curve without messing it all up) and masked off with tape. then you simply need to get the sanding implement of your choice and bring the hull down to the same level of the tape. It is quite important not to go over the line anywhere which is easily done with a hand file if you're being enthusiastic about it, otherwise you need to lower the top level of the hull and start again. do this too many times and you won't have any boat left!


Not much of a difference to the eye, but it was very noticeable putting supports for the deck across.

Next up, a very cheating way to make sure the supports for a deck are level if you're working at the very top of the hull. I used balsa at this part and epoxied it to the hull, making sure that no support was lower than the top of the hull. Given that balsa is such a soft wood, gentle sanding with the hull as a guide gives you a lovely flat surface to lay a deck on level with the top of your hull. It greatly increases work speed because you don't have to be nearly as careful sticking the supports in.


Finally, bringing us to the very last of the 'catch up', here's a photo detailing the stainless steel peg installed on the keel. I masked off the part of the fibreglass hull which was going to have the slot for the peg to try and stop cracking on the surface which could cause the whole part of the hull to disintegrate which would then require extensive work to fix. I haven't currently put anything into the hole to reinforce it, but if I notice the fibreglass is starting to wear with use I will install a stainless tube of similar diameter to the peg in the hull, similar to the mast holes on the top (but since those aren't going to be in direct contact with the water most of the time, brass should be sufficient).



Now, this fills all of the gaps left out up to this point in the build, all of the above had been done before the final photograph in the previous build post was taken, I just didn't include them, oops! Now, onto new stuff!
Firstly I put combings around all of the hatches. I don't really like hatches flush to the deck, they make it a pain to waterproof while still giving decent access to the compartments underneath, something that plagues me on both my Kormoran and my corvette (I do feel quite bad for the lack of progress there too), where I'll probably end up fudging in slightly raised platforms to hide combings on those two boats' stern decks. The combings go to very nearly the height of the structures that will be build on top of the hatches, such as the main cargo hatch, an access below decks and raised steering position (which admittedly is a bit of a fudge, in reality they were usually recessed. I'll also have to be careful with that, keeping in mind the sweep of the mizzen boom). This just keeps maximum security if the boat happens to be completely swamped by a wave or some other event and helps to prevent hatches being knocked off completely in freak accidents. To make the combings I glued some 1/8th wood strips to the underside edges of the hatches to provide a surface for the combing plates to stick to. I used superglue for this but I may in the future reinforce it with epoxy or the like, especially the inside corners of the combings.

It's worth noting that I laminated two layers of the same ply I used for the deck to form the combings. It makes the sheets fairly stiff and robust. Also note the notches cut out so the combings can straddle a support beam. Obviously there's a large hole fore and aft of the main cargo hatch where the decks change level. That needs fixing!



this makes a return to the use of cardboard templates, just like the deck. Given the asymmetrical nature of the hull, this is pretty much the only way to do it properly on this boat (ha! I said I was doing things "properly") and get a decent final fit. the gap at the bottom of the template is where the deck is bowing down slightly, I corrected this by adding a small piece of wood at the bottom of the panel made to cover the gap and clamping the deck to it until the epoxy had set. Hopefully it'll be enough to hold it in place, or a massive hole will open up at the worst possible part of the deck!


The wooden divide between decks goes in quite neatly and then I put combings in for the small hatch here once everything is set. Although the deck isn't quite a perfect fit here and there is a gap, there is a support running the length of the deck underneath it slathered in epoxy so in theory it should still be waterproof, although rigorous testing will show that up at a later date. Also this isn't the top layer of the deck, there will be planking above to hide this. The planking is also why I chose such a thin piece of ply to form the deck- strength will be singnificanlty increased by the planking and it also keeps the weight down.


Then I got to work on the masts. Both the main and mizzen are in two parts, purely because I think it looks cool, not for any historical authenticity. The masts were shaped on a belt sander after making the tops of each one with a circle to show how big they should be at each end and then each end was rounded off where appropriate. Two supports for each mast were fashioned out of ply and secured in place with epoxy. I ensured that it was a tight fit for all of the masts going in so there would be minimal slippage when it all set. The lugs to hold the booms to the masts were fashioned out of oak and a mixture of sawing and sanding to shape. Each lug has a notch cut in it with a corresponding notch in each boom, epoxied together then hidden with whipping twine tightly wrapped around and doused with superglue for strength. Although not finished this gives an idea of the eventual sail layout for the ship, with one square mast at the bow and two gaff rigged sails behind (possibly with detachable sails above each large sail too). The square sail will be linked to the mizzen boom and be pulled into position respective to the position of the mizzen boom.


Here she is with the masts standing to their full height- she's going to be a tall ship, but the masts are to the reccommended heights laid out in the original plan (even if that's the only thing I followed in the plan!). Also note I've started planking the deck. To do this I used some planking strips, cut them to length and superglued them to the deck. Between each plank is a strip of black mounting card which simulates caulking fairly well and will be sanded down to the same level of the deck when finished.

Next up we 're installing the shaft for the bowsprit to be plugged into. Like other models in the Portsmouth Model Boat Display Team, this model is using a short length of copper pipe for the bowsprit to be inserted into, being strong and resistant to wear as it's repeatedly assembled and disassembled. this pipe is mounted on a block to raise it proud of the hull at the bow.

The copper pipe was epoxied into a groove in the wooden block then a hole drilled all the way through the whole lot, this is for a brass pin to go through and pin the lot to the deck. Possibly overkill but I like the extra security.


Here we have the underside of the block. I've sanded a channel out for whipping twine to pass though. You can also see the wooden plug epoxied into the pack of the tube. this plug was a length of dowel inserted to the point where the bowsprit should rest then secured with a generous amount of epoxy. This part will be under all of the force provided by the three front sails if not being blown directly from behind so it needs to be tough as nails. the end of the whipping twine has been superglued here out of sight. The other end will also be glued here once finished. It's always a good idea to glue the first end in before you start whipping, so you don't have to hold it all in place. It's also good to be as generous as you can with the area you can glue the first piece on with- the more you can glue the more force it will take when making the whipping as tight as possible, something you want to do!


Here it is with the whipping twine on, this is partly decorative and party provides strength if the bowsprit is knocked upwards, it will help the copper pipe stay in place. Again the twine was reinforced with superglue with the excess gently dabbed away.


Here it is after final installation. the block was epoxied to the deck and the brass pin was passed through the whole assembly and into the deck itself, following a generous amount of epoxy down the hole which was heated to ensure it filled the length. The protruding length of brass once fully set was filed away. This is one of those rare moments where I managed to file it well enough that you can't feel where the brass is if you run your finger over the assembly! The shadows are through resin, there aren't actually any gaps. It's also worth noting that there's more whipping passed around the front end of the copper tube. This is the real protection from upwards force and the twine passes through a hole in the original hull itself which was drilled out prior to installation. Again, the thread was reinforced with superglue after the twine was in place. The old thread to mark the middle of the boat is still attached to the bow at this point, although it will be easily removed.


Here it is as of Christmas, with the bow assembly installed and the planking on the deck in place. I used three kinds of wood to plank with. The most abundant is a middle tone of wood, walnut I think but I can't be sure. There are a couple of odd planks with different wood, one kind a lighter colour (but the plank is also much thicker so will require careful sanding) and another a darker, rich red wood, which will form the planking on the hull. These varieties of wood are supposed to represent replaced planks at yards where the original kind of timber was unavailable, it also breaks up the deck a little but before I put things like loose coils of rope and stuff all over the place. I Tried to keep the pattern of the butts of planks realistic, but looking back I don't think the areas fore and aft of the hatches look right, especially with butt ends of other planks on the same level as they are, but none there. hopefully it won't be too noticeable. I should probably also plank the very fore section now that the support for the foremast is finished.


I put a couple of good layers of yacht varnish on the planking before cutting and sanding away the excess card 'caulking'. This is to help stiffen the card so it doesn't do something silly when it's being sanded and also so that black particles from said card won't lodge in the microscopic pores in the surface of the planking and can simply be sanded off, instead of becoming a real royal pain. Once the caulking and deck is sanded again andother decent load of yacht varnish will go on to protect it then I can think about putting a satin or matt varnish down to lessen the shine and make it look more like a working boat. But if subsequent messing around goes wrong I can always then sand it back to the original yacht varnish without damaging the deck. Here you can also see one of the red planks, just in front of the aft hatch. The outer and inner hull of the ship will be planked with this and varnished to a degree, which I think will look really nice. even if it perhaps a little too exotic for a simple trading vessel.
It's also worth noting that I didn't need to especially shape the ends of the planks overhanging the stern. Once varnished I simply sanded the excess back to be flush with the stern. I haven't quite finished sanding the overhangs at the edges of the changes in deck level yet though.

So that brings us to the end of the current progress of the ketch. hopefully I'll have an update again before the end of the year this time!
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unbuiltnautilus

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Re: Ketch Build
« Reply #18 on: March 07, 2017, 11:42:42 PM »

See that, it started out as the most cackhanded, cockeyed looking thing, but as the detail has been piled on, it has started to transform into a pretty looking model.
As far as build time goes, take a look at when I started the SS Ohio build, and that is still ongoing..I have been assured I am not long for the world now that I am half a century old, AND they just made me Chairman..despite this, I am enjoying the leisurely pace of construction, no hurry, it will be done when it is done. August 12th 2017, 75 years after the Pedestal Convoy sailed..mind you, I also said it would be ready for the 70th :embarrassed:


Keep up the good work, even if you find yourself landlocked, many miles inland, away from the sea air, where proper modellers lurk %)
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roycv

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Re: Ketch Build
« Reply #19 on: March 08, 2017, 08:32:42 AM »

 Hi looks great, may I suggest that you scrape the decks with a blade, you also get to the edges and corners easier.  I use Stanley knife type blades and then apply the varnish with a slightly padded cloth wrapped around a finger.  Comes out better than a brush does.
This is the only method I use now for planked decks.
Look forward to more.
regards
Roy
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Jack D

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Re: Ketch Build
« Reply #20 on: March 08, 2017, 01:08:04 PM »


See that, it started out as the most cackhanded, cockeyed looking thing, but as the detail has been piled on, it has started to transform into a pretty looking model.
As far as build time goes, take a look at when I started the SS Ohio build, and that is still ongoing..I have been assured I am not long for the world now that I am half a century old, AND they just made me Chairman..despite this, I am enjoying the leisurely pace of construction, no hurry, it will be done when it is done. August 12th 2017, 75 years after the Pedestal Convoy sailed..mind you, I also said it would be ready for the 70th :embarrassed:


Haha, here's hoping the Alberni is ready for the 80th anniversary of her completion!


Hi looks great, may I suggest that you scrape the decks with a blade, you also get to the edges and corners easier.  I use Stanley knife type blades and then apply the varnish with a slightly padded cloth wrapped around a finger.  Comes out better than a brush does.
This is the only method I use now for planked decks.
Look forward to more.
regards
Roy


Thanks! That's really good advice for the deck, a cloth will make things much smoother to go on. I'm going to be using a blade to cut down most of the caulking, not sure if I'll be able to smooth the wood itself down though.
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