Build a Dinghy: Part 22 Quarter Knees

As described in Part 21, these quarter knees were cut carved and shaped from a glue-up of 1" x 4" pine . That way I didnt end up with "short grain" along one of the "arms" ( You always want wood grain to follow the load paths.) Shaping was done with a low angle block plane, a spokeshave and a rasp. The rough shape was cut with a jigsaw. These will be installed 1/8" high of the sides and transom, then planed flush for a mating fit.

Build a Dinghy: Part 21

I made my quarter knees--the corner braces at the transom-from a glue-up of 1-by pine.I lapped the corners and and sed four boards for each "blank." I the cut the actual knees to shape, beveling their sides to fit the flare of the boat sides and the rake of the transom. Gluing up this way allowed me to orient the grain in the direction of the stresses. It is stronger than a solid piece of wood and easier than laminating curved pieces or steam bending. Here's a pic of the blanks in which you can see how I arranged the overlapping glue-up. I will post a picture of the final shaped knees later. Here, I have beveled the arms that rest along the transom, using a block plane. More shaping and beveling to come.

Build a Dinghy Part 20

First coat of paint went on and I'm happy with the job I did sanding and fairing. Cant see the 'glass om the chines. Ok, I can, up close, but it came out really good. If you are sharp-eyed, you'll notice I have'nt yet painted the port side of the boat--thats the side on the right in the photo. There, you can see the biaxial glass cloth. I'm treating this first coat as a prime coat anyhow: it showed the high spots and other minor imperfections that where hard to see on the unpainted wood. Most of this coat will get sanded off, then I'll aplly the "real" first coat--and then one more!. That messy rubrail low in the picture? Thats masking tape. Those rails are going to be finished natural.

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!

Build a Dinghy: Part 16

I cut and shaped the skeg out of 7/8" teak ply--marine grade. Glued it in and it looks sweet. I have the rails--the gunwales or guards if you prefer, soaking to make them easier to bend. Pics soon--promise!