Daggerboard!

Because I want to sail this bad boy to Port Lincoln eventually it has to be able to, well, sail. That means it needs some lateral resistance. Thats what lets the boat move in a direction other than whee the wind is blowing. This can be a keel or a centreboard or, in this case, a dagger board. (A centreboard swings up into the hull whereas a daggerboard plunges straight down.

The daggerboard case has to come up it the hull a fair way so that it can be open at the top and not flood the boat. It also has to resist quite a bit of lateral force so needs to be reinforced quiet well. The photo above shows the inside of the case. It has to be epoxied on the inside before closing so it is all waterproof. The angled bit at the back allows the case to double as a support for the middle thwart (seat). The photo below shows the case in place and the thwart reinforcing it.

Gunwales

Gunwale is probably the classic example of marine terminology being just bloody odd. Its pronounced Gunnel, like tunnel.

I wanted a classic look to this little boat so I went with a spaced gunwale. This means an inwale (innel) spaced from the gunwale. It really stiffened the top of the hull when finished. I think its actually a bit stiffer than just a gunwale because of the width of the laminate. Its a bit of a work boat thing.

The spacers are cut either end using a large spade bit drill to make scalloped ends. Its notched intot he breasthook in the front and the quarter knees at the back. Its a bit unclear in this photo but you can see the completed gunwales and floors.

You can see in this photo I've also added the thwart and a cross member for the rear sear. There's probably a name for that too but I haven't got the

plans with me now.

By this time I had filleted all the lands inside and out. Thats the joins between the planks. I mixed up filler thickness epoxy and used a big syringe top squirt it into the joins. Then its just a matter of sort of squeegeeing it to a neat profile. Its a bloody lot of bending over.

Because the width of the join between the two bits of timber is increased it adds to the strength a lot. you can sort of see the finished join below.

You can also see some bubbles in the epoxy painted on the ply. Thats actually good. It means the epoxy displaced gas in the timber and soaked it. I'll sand it all with fine paper (800 grit) and give it another coat.

Half way there!

You might reasonably think once the thing looks like a boat you are almost done. How naive! When the hull is finished and you turn it over you are anywhere between 10% and 50% through the project. I'm only putting in some seats (thwarts) so I'm about halfway there. If it was a bigger boat with a cabin I would have really only just started the hard work. Oh I also have to make a mast, a boom, a yard and a couple of oars, oh also a rudder and a centreboard. But thats it. Bugger!

This picture shows the hull the right way up with some battens across it to check the sheer (top of hull) is level before starting work on the inside.

The first piece of work is the breasthook (great word!) This reinforces the bow and, as it turns out, is an incredibly fiddly piece of work. Every angle is unusual and the whole thing takes a lot of fitting, checking, adjusting and refitting. It should be a bit rounded on top. I made it out of a piece of Australian Oak wardrobe. The timber is nice so I will probably bright finish it (clear varnish).

Next piece of reinforcement is the floors. Not what you'd think. If you want to talk about the floor of a boat you say the sole. The floors are the structures running across the bottom of the boat which stiffen the hull and on which the sole sits. Again (like most pieces of the boat) these are a complete bugger to get fitting correctly. Interestingly the hull without reinforcement was very floppy and bendable but after the floors the bottom bit of the hull became totally stiff.

Turning over!

With the planking and keel done there is no reason to keep looking at the boat upside down. Firstly I did a heap of screw hole filling (I know I said I was doing it as I went along, but there were a heap I missed). Then there was the sanding. Anyone who has built a boat will tell you that 3/4 of the entire build time is spent sanding, that is if they don't die of black lung before you meet them.

The whole hull was only actually held down to the moulds in a few places. It was simply a matter of unscrewing

these fastenings and lifting the hull free of the moulds. Except it wouldn't come off. I assumed there must be a little dribble of epoxy somewhere that had attached the hull to the moulds so I gave it a really really big yank and it still wouldn't come loose. In fact the hull started to distort quite a bit.

Then I remembered the other screws holding it down. Once they were out it came away very easily. I was amazed how light the whole thing is. Obviously there are thwarts (seats) and a few other internals to make it a bit heavier, but the epoxy gluing each lap means there will be minimal need for further internal structures like ribs. It a bit wobbly though so some stiffening will be appreciated before I take it to sea.

Outer stem and keel

The keel serves a number of purposes. Obviously it has a limited structural value because I've finished the planking and it still hasn't been attached. The keel keeps the boat tracking true, a bit like being on rails. It also acts as a big rubbing strip for when the boat is dragged across surfaces. For that reason it should be made out of a carefully chosen hard wood that will wear well. I made mine out of the door of a cupboard I just demolished. It looked like handy timber at the time so I kept the useful bits. I think its Australian Oak. Its basically just stuck on top of the keelson. Sometimes screws are put through from the top of the keelson but decided to put my faith in the epoxy (plus a dirty big epoxy fillet down each side that you will see later.

The keel doesn't run the length of the boat uninterrupted because the centreboard needs to drop down through the middle of the boat when sailing to further maintain direction when the wind wants to push the boat sideways. So a gap (centreboard slot) needs to be incorporated. I cut the slot in the keelson a while ago. Basically I just cut bits of the Australian Oak to go around the slot and shaped them so it will look smooth.

At the front the keel becomes the outer stem as it turns up. This is a second piece of laminated timber (I used the inner stem as the pattern). The join between the outer stem and keel is stepped to increase surface area glued. Wow its all getting a bit dry. Just look at the pics and it will make sense. Once it was all glued it was planed/sanded until it was all rounded and smooth.

This picture shows that stepped join. The Aus. Oak keel is on the left and the laminated outer stem on the right.

More Planks

So there's been a bit of a break in posts here because I've just been doing more planking. It turns into a bit of a procedure you get better and better at. I cut a template for pretty much every strake except one where I was left with a bit of marine ply the size of a blank template. The instructions say you only need to do templates for the first few planks but a sheet of 4mm Okume marine ply is a bit over $100 and as each post reiterates I'm a tight arse. If I'm going to make a mistake it'll be on el-cheapo MDF.

This is such a small boat I found I could make templates, cut two planks from the good ply and then attach them with epoxy (one either side) in a three hour burst. A bigger boat would be a much bigger procedure. My dad is finishing a 5m Thames rowing skiff and I'm stuffed if I can work out how he managed to do the planking by himself.

Epoxy is so versatile I mixed a bit of extra filling powder with any epoxy left over from each gluing and did the hole filling (where the previous planks were temporarily screwed as I went.

The instructions say each plank doesn't have to quite have to touch each mould. Apparently a deviation of up to 5mm to ensure the planks curve smoothly is fine. I may have just exceeded the 5mm but the planks are nicely curved (fair). As well as the curve from stem to stern there is the up and down curve to consider. This is much harder to predict when planking a boat you've never actually seen and doing it upside down. The second photo (below) shows how the plank widths and angles vary a bit as the reach the stem. Don't tell anyone.

Some texts say you can use almost anything powdery as filler with epoxy so I thought I'd try this using some some of the fine saw dust from the random orbital sander. Turns out you can take the tight arse thing too far. The result is OK but sort of coarse and doesn't smooth well before it sets so you have lots more sanding to do later.

When all the planks were on I bought some more meranti architrave, ripped it down and attached two rubbing strips, at the top and bottom of the sheer strake, a-la working boat.

The first plank!

This is a bit of a milestone. I put the first plank on (well a boatbuilder would call it a strake - hence lapstrake being the style of construction because the strakes overLAP). Because of the overlap you put the bottom strakes on first. The bottom strake is called the garboard - I have no idea why.

Its a bit of an involved process because the strake has to be exactly the right shape. I got some cheap 3mm MDF (medium density fibreoard, otherwise known around here as craftwood) to make a pattern first. The MDF is cut to a bit bigger than will be needed and clamped down to the moulds. Then the marks on the moulds relating to the garboard are transferred onto the pattern. The strake turns from flat to horizontal at the stem on the garboard strake which makes for quite a curve.



Once the pattern has been marked and cut out it is tried on (offerred up) again to make sure its just right. (which it usually isn't and needs a bit of modification) It pays to be patient and measure twice cut once because i the shape isn't quite right the whole thing is going to look wonky when its done.

When the pattern is finally right it is clamped to the marine ply (4mm) and marked out. Ideally you would clamp it to two pieces and cut both at the same time to make super sure they were identical (one strake for each side) but this reuires lots of room and I don't have that. I cut out one then used the pattern to cut the other. Then I clamped both together and planed the edges until they were identical (well OK I should have planed them but I used a random orbital sander beacuse it was quicker)

Anything you don't want the epoxy to stick to, such as the moulds, you cover in plastic tape which is imune to the sticky super powers of the epoxy. The epoxy is mixed up (its just industrial two part glue like araldite) and then mixed with filler powder so its the consistancy of honey.










The keelson and stem are epoxied and hen the strake clamped from middle to the ends. This is bloody fiddly. The epoxy lubricates the two pieces of timber and they want to squirm around as you clamp them. You also have to be really careful where you clamp so that the strake is still following a smooth line and not a series of bent straight lines.

Essential equipment

With any set of building instructions come a list of equipment you will need. To be honest I don't think I've yet built anything while in posession of all the required tools. Hell, I carved a wooden rocking horse with nothing more than one square chisel and the liberal use of a belt sander and it turned out just fine.

For every tool you don't have you will need to be a bit more inventive or take a bit longer but a lack of fancy tools shouldn't stop you having a go.

There are a few things I think every shed should have. Some of these don't even have an immediately obvious purpose, but you will be the poorer without them. To this end I always like to have a dog somewhere nearby. The dog I use for day to day shed work is a large kangaroo dog called Baby Des. He serves several purposes. When too many small pieces of off cut timber are lying around Des will kindly remove a few and chew them to bits. If the air is becoming too clear and sweet scented he can remedy this with his own special formula. Most importantly he is the safety officer. I'm not the mosst tidy person and as a project progresses the shed becomes more and more cluttered with junk. This includes dropped or discarded screws and nails. I've trodden on these before and had them go deep into my foot which can spoil your whole day. Des is able to interpret the task for the day and exactly where will need to be to perform this task. He will cleverly position himself in such a way that I have to step over him the maximum number of times, thus ensuring I am always looking down to avoid both dog and pointy objects.

The keelson

The keelson is also called a hog, I don't know what the difference is. Its the bit of timber that this bottom planks (garboard strakes) are attached to. It is planed so it will match the angle of the planks (strakes).

A notch is cut into the moulds to hold the keelson.

Because the keelson has to curve a fair bit it is made out of two laminates. Now a real boat builder would use Brazillian Mahogany or the like. I am not a real boatbuilder. As each blog post reinforces, I am a tight arse. I bought some meranti architrave from the local hardware shop and ripped it down to 70x10mm planks.

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At the appropriate spot according to the plans I cut the centreboard case slot once the keelson had been epoxied, clamped and dried. I did this by cutting a hole the width of the slot and then using a jigsaw to do the rest.

The stem part 1

The stem is effectively the front of the boat to which all the planks attach. If you want to be pedantic the outer stem is the front most part of the boat, but its really there just to finish off the look of the boat and protect the rest of the structure when ramming Japanese whaling vessels.

The stem can either be cut out of wide planks or laminated. Because the stem for the Auk is a gentle curve it would need to be cut out of cery wide planks, and as it has already been established that I am a tight arse I will be laminating mine. It so happens I have some left over bits of thin marine ply (3mm) so i don't have to buy anything and my tight arse is a happy one.

The shape for the stem is derived from the plans and marked out on a flat bench. Blocks are then screwed to the bench, to which the stem will be clamp
ed. I've made the curve just tighter than the stem will be because it will rebound just a bit.

About six strips of thin ply were cut. I did a dry run to make sure they would actually take the bend and not snap. 3mm play is petty bendy!












They were then covered on both sides with thickened epoxy, (thickened to the consistency of phlegm). This is all sandwiched together, wrapped in glad wrap and clamped to the blocks from the middle out. The epoxy hardens in 24 hrs. It only rebounded about 5mm in the end. The glad wrap got stuck in the epoxy that oozed out and I had to sand it all off together which buggered a sanding belt. It's really strong.





















Then I attached the stem to the building frame. I made a little bracket to hold the stem onto the first mould. Below is a photo I took of the stem once the keelson was attached to it (I'll talk about that next). I've started to shape it.

Moulds

The moulds are the shape template for the boat. They're like cross sections at regular stations - that is points at right angles to the centre line of the boat. Full size patterns of one side of each mould are usually supplied in the plans. Its just a matter of draw a centre line on the mould timber. (anyting flat and thick will do - Mine is a mixture of 12mm MDF and 12mm ply which were previously moulds for my Dad's Thames rowing skiff) Then mark out the shape with a hamer and nail, or fancy spike thing for doing this job.


You turn the plan over and re-use the same holes to do the other side of the mould. The dot are joined up and then cut out with a jigsaw.

Everything is lined up on the strongback (building frame) along the centre line which is a string line running on top of the buidling frame. In the horizontal planeeverything is lined up with the level of the top of the building frame. The moulds are attached to the building frame to align with these two requirements. This is fiddly on your own. In this case the moulds are so close together its hard to get a screwdriver inbetween them.



Above are the first two moulds. I'm a tight arse and skimped on ply by not continuing the mould all the way to the building frame. I'm using bits of off cut.

Here you can see all the moulds in place. Having built them all I read that you can actually leave every second one out in such a small hull. Oh well. I plan to use light ply to minimise the weight so having all the moulds will prevent the light ply from sagging between stations.

After mounting all the moulds they are checked from all aspects with battenns to make sure the moulds are fair (smoothly curved). Bit of adjustment needed on the nearmost mould below.

Lastly the moulds are all held vertical by reinforcing one mould towards the front and one towards the back, then screwing spacers between all the moulds. By now its all really stiff which is good because attaching the boards will want to twist the whole thing.

What and Why

I've read Wooden Boat magzine for most of my adult life. Finally having built a house and a few other things I've got around to building a wooden boat of my own. I've already built a chesapeake twin sea kayak to get the hang of epoxy. Its amazing stuff.

In preparing to build the boat I would have loved to see some photos, not diagrams, of a small lapstrake ply and epoxy boat being built. This will probably descend into obscure jargon occassionally but I will try to make it as straight forward as possible. I think boatbuilding need not be any more difficult and therefore inaccessable than any moderately complex task such as


This isn't me but it is one of the few good photos of the Iain Oughtred designed "Auk", a ships tender. I plan to have a sail rig for it so it will have a centerboard and rudder as well as oars and rowlocks.

I'll be building a particularly small version (it can be a bit either side of the stated 7'8" - 2.36m by changing the interval between the building moulds. The reason for this is twofold. Firstly the longest plank will just be able to be cut out of one sheet of 2440x1200mm ply if I keep the length to 2.16m. The second reason is it will be lighter when I have to carry it over to the dam to let little people go for a row.

Construction will be a fairly standard combination of old and new technologies. The form is pretty ancient dating back to the ninth century AD. Its called either lapstrake or clinker depending on where you were born. The material, timber, is old too. Originally the hull was made of planks now I'm making planks of marine ply. The fastening is all new technology. Epoxy resin is used a sealer when applied neat and as a filler when mixed with fibre dust. Its amazing stuff you can do almost anything with. The boat is so much stronger without he need for half the internal framing.