: This is not the first time I have asked this question, but I want to revisit
: it- I would like to know if anyone has built a SOF using mahogany for the
: gunwales and keelson. I have access to smaller lengths of fir and pine for
: the ribs and shorter pieces. It's the long ones that are killing me to
: find in good lumber. Where I live mahogany is readily available in very
: clear grain, and long lengths. Besides, imagine how beautiful she would
: look with Mahogany gunwales, even if you don't see much of them!

: My research on the web shows that it is about 33% heavier than spruce and
: about 15% heavier than fir. If I use mahogany for the gunwales and
: keelson, and fir for the rest of the boat, is it really going to add that
: much more weight? The cost of (a) purchasing good clear spruce and (b)
: shipping the good clear spruce to me is just too much. If mahogany is only
: going to add 3 or 4 pounds then what the heck. I can lose 3 or 4 pounds of
: body fat to make up the difference!!!

: I also would like to ask if anyone with some experience in building a SOF in
: traditional methods would like to comment on the idea of shaving 1/8"
: off the gunwales, keelson, and maybe stringers if they were made from
: mahogany. My thought is the mahogany is much stronger, and much less
: likely to crack around the mortices, so I could go a tiny bit thinner with
: the gunwales to make up for the difference in weight. The mahogany I have
: access to is very dense, very tight-grained, and would be quarter-sawn.

I'm building a non-traditional, Yost-style SOF loosely modeled on Tom Yost's multi-chine Sea Rider. I cut the gunwales, chines, and keel and deck stringers from a 13-foot board of Honduran Mahogany. Because the kayak is around 18 feet long, the mahogany I had access to was not really the answer to your problem of too-short spruce/fir/cedar, but I thought it would be strong, easy to work with, and nice to look at. Rather than scarf or reinforce butt joints, I ripped each piece to 3/8" (x 1 1/2", 1", or 3/4", depending on the type of stringer). Using the example of the gunwales, I cut simple 45-degree scarfs so that I would have four 3/8" x 1 1/2" strips, two approximately 12 feet long and two approximately 6 feet long. Then I laminated the four pieces so that I had an 18-foot, 3/4" x 1 1/2" strip. I laminated them in place on the cross-section forms (temporarily), so the laminated piece had the curved shapes built in.

This has proved to be a LOT of extra work, epoxying, clamping, then planing and scraping to remove glue and even up the edges of the laminated strips, but I'm pretty pleased with how it's turning out. I haven't got any idea yet how heavy it is or how much heavier it is than if I had used Western Red Cedar or the like, which I couldn't readily find in long, clear boards around here. I think it's probably over-built and unnecessarily heavy, especially since there are six chines instead of two, but we'll see. If I were going to do it again, I think I would glue up strips that were 5/16" or even 9/32" so that the resulting laminations would be 5/8" or 9/16" thick instead of 3/4", because the mahogany and the lamination make the pieces pretty sturdy.

Every time I do a sneak-preview by rubbing a little mineral spirits on the mahogany, I get pretty excited about how the wood will look from the inside of the boat (and from the outside during the time when I use a clear vinyl skin before I get around to sewing a fabric skin on).

Any suggestions on finishing the wood to bring out its color and feature? Teak oil, tung oil, varnish, polyurethane, some combination?

Thanks, Tom, by the way, for your designs and inspiration. Originally, this project was supposed to be a dry run to see how I liked the changes made to your design before building a folding version, but I got carried away. I can't wait to get this one in the water to see how it performs and then get started on a folding version (and two smaller folding Sea Pup designs for my kids).