: Hi!

: I've seen a few people do the pai all in once piece, instead of multiple
: layers of plywood like the Yost instructions do it.

One piece? Or solid wood pieces bent and attached (lashed, pegged, or glued)? You could potentially build up a coaming from 2 steam bent pieces (vertical wall and lip). Or laminate several thinner strips.

The coaming shown in the attached photo was made bent ash strips (2 strips 1.375"x0.20" and 3 strips 0.375"x0.20"). The strips were cut to length with a 6" scarf. They were soaked in water for a week then bent around a plywood mold. Steam bending was not necessary, but a heat gun helped persuade the strips to make the tighter parts of the bend. The strips were clamped up and left on the mold for a week to dry. If the strips are thin enough (1/8") they can probably be dry bent. The strips were glued up in 2 stages. One day I did the 2 tall strips. The next day I glued the 3 lip rings to the wall. The day after that, I cleaned it up and rounded the corners with the router and sander. Then drilled the holes to sew to the skin.

I have a few pictures of the process mixed in among the other building steps on my web page linked below.

Schade covers bending a lip onto the coaming in "The strip-built sea kayak"
Cunningham discusses bending and lashing a coaming in "building the Greenland Kayak"
Morris also has a few pages on bent coamings in "building skin-on-frame boats"
Yost shows making a coaming from quilting hoops buried in the folding manual, coaming section.

Pretty much any book on building wooden boats hits bending somewhere. The references mentioned above specifically address the kayak coamings.