I'm finishing up a Wood Duck 12 from plans and I have a question for all you strip builders out there about the coaming (I already made a Shearwater 14 from a kit so I know the recommended drill for stitch and glue coamings).
Since I didn't have a spare sheet of 18 mm plywood around to make the coaming risers, but I did have a pile of bead and cove cedar strips, I decided to use the old vertical-cedar-strip-plan for the coaming riser plan, with a slight modification. I cut the strips 3/4 inch long and hot glued them on the top of the deck (instead of onto the inside edge of the deck like most builds I've seen online). I also used Titebond between the strips. Looks good, feels sturdy, and was kind of fun - like a jig saw puzzle, but it didn't matter where you put the pieces, they all fit!
Here's my question. The cedar strips are not very thick, so the coaming riser is only 1/4 inch thick (and 3/4 inch high). I was originally going to do two rows of vertical cedar strips (one outside the other) to make the total riser thickness 1/2 inch, more like the thickness of the pieces of plywood that are stacked to make a "normal" stitch and glue riser. I have already cut out the coaming rim from Okume, and it's about 1-1/2 inch wide so I didn't think it would work very well if I put something that wide on top of the single-walled 1/4 inch thick riser (too much leverage on the outside edge). However, I know that most cedar strip boats that use the vertical strip riser method only use one thickness, and then have a much thinner coaming rim. I'm thinking I could either:
1. Cut existing coaming rim to "x" width (what should "x" be - 1 inch? 3/4 inch? It really only needs to be thick enough to hold a spray skirt on right?)
2. Put on my planned extra row of vertical strips and use the existing width coaming rim.
I am planning to fillet the outside strip-deck joint on the vertical strips and put a layer of fiberglass both inside and outside the strips so I don't think it will be a strength issue if I leave just a single row of strips. My concern with the double row is how to make sure the two rows are glued together enough so they will be structurally sound since there would be fiberglass on only one side of each row. Would it be best to use thickened epoxy to install the second row to make it a good bond if I go this route? Will the two-row idea add a lot of weight? Do I need it?
Any thoughts from someone who's done this type of coaming?
I'm leaning toward the single row, trim the existing coaming rim narrower idea at the moment, but wanted to see others' opinions before I do any cutting.