Building the Squirt - Part 1

by David McAdam

I had worked in a joinery during the summer months while I was in college, so I was "in the know" when it came to getting suitable timber. I paid a visit to my old boss one Saturday, and two weeks later, collected a sizeable quantity of one inch African ribbon-mahogany (sapele), planed on all four sides.

However, marine plywood was an altogether different kettle of fish! One would think, that living on a small island where ship building used to be a big industry, marine ply would be easy to find! I must have visited five or six places that claimed to sell "marine" plywood, but the stuff was obviously of very bad quality, with attractive but extremely brittle outer plies. The conversations with the dealers usually went something like this:

Me: "Do you sell marine plywood?"
Dealer "oh yes we have any amount of it!"
Me: "ok I'll call to have a look at it, I'm using it to build a boat."
Dealer: "hmm I wouldn't use it on a boat if I were you..."
Me: "so its not really marine ply then?"
Dealer: "splutter...choke...cough..."

I learned rather quickly that the plywood with a "marine plywood" stamp on the edges of the boards was not genuine, but if the stamp was on the face of each and every sheet, it was the good stuff.

Eventually, I found a company in Dublin who knew what they were talking about and who had genuine Lloyd's registered BS1088 plywood. I bought several sheets of 6mm three-ply mahogany. I also bought 2 gallons of West Systems epoxy and a tube of microfibres.

Since the shed used to be a cattle shed, the concrete floor was slightly sloped. I made up the building form using 2x4 timber and glued and screwed it together to make sure it wasn't going to move. I had to use spacer blocks underneath one side of the form to make the whole thing level. Checking with a spirit level as I went, I then used L brackets to bolt the frame to the concrete.

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I used carbon paper to transfer the frame patterns to the mahogany. Using a jigsaw (sabre saw), I cut out the frame parts, leaving them 1-2mm oversized. I then used a spokeshave and a jack plane to fine tune the frames to the correct sizes. I used some 3/4 inch bronze boat nails to attach the plywood gussets to the frames, and glued everything together with an epoxy & microfibres mixture. It was November by this stage and the weather was pretty cold so I made a large timber frame, stapled some polythene over it and heated the enclosed space with a fan heater on a timer. It probably added €50 to my brother's electricity bill (he still blames his wife for spending too long in the shower). I positioned the frames and the transom on the building form, securing them in place with blocks of wood screwed into both the form and the frame. The breasthook and stem were positioned and glued in place. I used large blocks of wood fixed to the floor, to keep the breasthook at the correct height. Bronze bolts were used to bolt the transom, keel, transom knee and stem together.

The next part was to bend the chine and sheer into position. I ripped them both in half on a bandsaw. This made them much easier to bend around the frames, without steaming. Before I bent them, I wrapped them with towels and poured boiling water over them. This made a massive difference and the wood was pretty easy to bend. I did break one of the sheer pieces, due to some cross-grain. Luckily I had a spare! The chine and sheer pieces that I had bought were not long enough, so I had to scarf-join them together. I used a tenon saw and a hand plane to make the joints. Using greaseproof paper to stop things sticking to the bench, I used a nail gun to hold the joint firmly until the epoxy had cured. Using clamps and bronze screws, I fixed the first layer of sheer and chine pieces to the frames. After epoxy setup, the second layer of sheer and chine was epoxied and screwed to the first. I used normal steel screws for this, spaced every few inches. The screws were removed later and the holes filled.

The battens went in place easily, actually they were a breeze compared to the sheer & chine!

The fairing process took quite a lot of time, I must have spent several days doing it. In fairness (pun intended), I probably spent more time looking, wondering and head-scratching than actually fairing! I think that's the only way to get to grips with it. It really is the artistic part of boat building, where your judgement and "eye" are important. I used a hand plane and a rasp to do most of it. I only used the electric plane to rough out the forward portion of the sheers. I felt more in control when using the hand plane.

The best advice I can give, if the fairing process intimidates you, is to learn how to sharpen your plane properly. I had three spare plane blades, so I could swap them over when they started to get blunt. After about half an hour of continuous fairing, the blade usually becomes noticeably more blunt. I spent a lot of time working on the rear portion of the bottom of the hull, to ensure it was dead straight and level. I used a long spirit level to check for straightness. For the sides and the portions towards the stem, I bent round some 6mm plywood to imitate the planking. This was helpful to determine the correct angles to plane on the chine and sheer. I had to glue extra material onto the chine from frame two forward, because I had not given the chine enough twist when I first installed it. When I was satisfied with the shape of the hull, I went over the entire thing with a sanding board. It was easy to see where there were any low spots because the sandpaper did not leave any scratch marks there. When there was an even scratch pattern on all frame parts, I was happier that everything was 100% fair. I left the hull for two days and then came back for another look and noticed a few small humps, which I evened out. If you look at something for too long, it becomes hard to see! I found that by leaving it for a day or two, a fresh eye picks up things more easily.

It had just turned the New Year, 2004, and I was very happy with my progress so far. I had transformed straight lengths of wood into a curvy, almost living skeleton!

Next WebLetter will feature Part 2: Planking