About the paint.................. Do it with thin, light coats.
Now everyone already knows that you are supposed to apply paint and varnish in thin coats, the problem is that very few people do it that way. In this case, it really is the only way to do it. The varnish is very hard to see on these thin pieces of wood, and if you leave a gap in the coating the wood will rot. Not, maybe it will rot........... it definitely will rot, period.
The application of several thin coats not only makes the varnish stay on longer, it also decreases the odds that you will miss a spot.
You don't really need to paint or varnish the frame to death. You are
just sealing it from the intrusion of water. In places where there
will be a lot of contact, you can put on some extra coats, but so long as it
is sealed from the water, a little is as good as a lot. Just do it as
though you were wrapping a piece of wood in Saran wrap. What you want is several thin
coats, with no gaps.
"How much paint do I put on the cotton duck material?"
You will NEVER get the canvas to be smooth. (The cloth on a canoe can be filled and painted smooth because it is backed with wood, and is not subject to movement.) If you try to fill the weave on this style of kayak, you will end up with paint that is a mass of cracks the first time you step into it and move the cloth.
Cracks in the paint lead to enormous problems. It allows the water and dirt to penetrate further into the paint and reach the cloth fibers. Adding more paint at this point is a lesson in futility, because that makes the paint thicker and causes it to crack even worse.
The trick is to have the paint seal the cloth but not make it at all stiff.
If water seeps through the hull, you can always add more paint, but there is no way to get it off once it is on.
That gives you an idea how thin you need to keep the paint.)
It is a good idea to paint a stretched piece of scrap. Staple a piece of the cloth to an old picture frame, or one you just nail together. Then shrink it, and after it is dry you can try paint mixed at different consistencies to see how well it is going to penetrate the cloth. Once you hit the right one you will see the paint go right into the cloth and soak through to the other side fairly well.
Completing the bottom first usually works out the best. I do the bottom completely before putting on the top for two reasons. The first is I need to seal all the canvas. If I staple the vinyl over the edge of the canvas then I cannot get the paint where the cloth is stapled to the gunwale.
If you leave canvas unpainted in this area it will absorb water, and rot fairly quickly ,and the life of the boat will be shortened.
The second reason is that once the paint on the canvas is dried it is real easy to trim it right along the top of the gunwale piece.
You want this to be a nice neat job because if it is raggedy, you will see a row of bumps along the edge of the vinyl. When the paint is set up well, you can do a neat job of trimming it with a good sharp razor knife.
If you are planning to use #12 cotton duck for the top deck, you will need another quart of paint. On this cloth you want a thin layer also to avoid cracking. Generally when I paint a top I am making a camo boat for taking pictures or duck hunting.
