October 12, 2009

Build a Dinghy: Part 19

After installing the rails and breasthook, I flipped the boat over and glassed the chines. I used 6-inch wide biaxial tape, which is lower profile than woven cloth.( Its knitted, so doesnt have the ins and outs of a weave). It also doesnt have a hard selvage edge to have to sand and fair in smoothly. Its also stronger.
First I dry fit a cut piece of biax. Then I applied epoxy resin to the chines. Then I smoothed the fabric in with a plastic spreader. then I used a spreader and brush to apply more resin atop the fabric, wetting it out.
After that cured for 24 hours, I applied another coat of resin to fill the weave, "painting" it wide of the fabric edge to help fair it in. After that cured, I mixed Microlight fairing filler with resin and "bogged" the chines, making a real smooth transistion from glass to wood, as you can see.
I then coated the entire hull in epoxy. I wasnt planning in this--its optional really, adding weight and expense--but I had som many drips that I brushed out from apllying the 'glass to the chines, that the boat was half-coated already. So I just rolled on another coat,tipping-off with a foam brush to remove the stipple.
Finally, you see the glass-like surface and the new "owner" in the shop for a progress check (my daughter Keira)

Build a Dinghy: Part 18

To put the guardrails--rubrails, guards, pick your term--I had to soak them in water for a few days. I used a piece of gutter to do this, blocking the ends and filling with water. Then I weighted the wood to keep it submerged.
When I tried dry fitting them, they crackled alot at the transom, where in addition to a good bend, the rails also have to twist to follow the sheerline. Soaking them made them pliable. I then clamped them in place, then let them dry for three days, removed them, applied glue and put them back. This is every boat builders favorite shot: every clamp in the house (almost--49 clamps; I own 58!).
Youc can see in the top pic how the rails over hang the transom. After teh glue dried, I cut them flush using my Japanese flush cut saw. Using the boat to make cuts that way ensures a perfect fit every time.

Build a Dinghy: part 17

Here is my skeg, cut from 5/8" teak plywood. I shaped it and cut it flush with the transom after it was glued and screwed. The first step is shown here, where a pencil sliding on a wood scrap is used to scribe the shape of the bottom rocker onto the skeg.It fit PURR-fectly!