I've been thinking

[Bellybuster]

I've been thinking about better ways to do the rubrails on a ply boat (skiff or pirogue)
What if.......one was to secure both the inner and the outer rails 1/4" above the side panel. It would give you a 1/4" well of sorts for some thickened epoxy which would cover the exposed sides of the plywood. I spent hours cutting and tweaking a lip or shoulder of sorts on my rubrail to cover the exposed plywood and this would be quick and easy. I think it would considerably stiffen the boat too maybe.
just a thought

 

[seedtick]

That will certainly work but why not just add a third rail on top of the inner and outer rails?

It doesn't have to be real thick, just wide enough to cover the thickness of the outer rail + plywood + inner rail

 

[shikeswithcanoe]

Lowes carries these plastic U shaped "edge caps" that are used for making the edges of decorative/gardening lattice work look nicer.

They are 8 feet long, about an inch tall, and about 3/4 thick. They have a deep channel running the full length thats a bit over 1/4 wide, maybe even up to 3/8 wide. They come in white, brown/red/ and a hunter green. Cost about a buck a foot.

Should make a perfect protective cap for plywood edges IMO. Probably last forever even if you abuse the heck out of it.

 

[oldsparkey]

Where the sides match up with the rails , that area I put a coat of epoxy over along with the sides of the rails , then a day later another one to seal them. Later a couple coats of varnish to seal the deal.

Chuck.

 

[Kayak Jack]

Friend BellyBuster, if it's stiffness and rigidity you're looking for, you may not need to double up and add that much weight. In two beams of the same weight of material, the one with more height is stronger than the one with more thickness. Consider constructing a beam (gunnel assembly) that is thinner, but taller. Rather than 1" thick X 1" high, consider 1/8" thick X 3" high. Think of a strip of 1/8" plywood glued to the edge of the hull, either inside or out.

If you want thickness, think of a ventilated gunnel, spacers in between the hull (parent material) and the reinforcing strip used as a gunnel. These spacers need be no more complex than 1/4" thick slices off of a closet rod (2" diameter dowel), or slices off of a wood strip. Mine were in the shape of isosceles triangles, with large holes drilled in the center to reduce weight even further. I had a row along the top edge of the 3" wide strip of 1/8" plywood gunnel, and another row of spacers along the bottom edge of it. There is a 2"-3" gap between spaces in each row, and the rows are alternated so a bottom row spacer is located immediately beneath a gap in the top row, and a top spacer is immediately above a gap in the bottom row.

My strips of plywood for gunnels are shorter than the length of the boat. Since most stress occurs in the middle of the boat, my 5' long strip is in the center, with shorter chunks spliced on the ends to teach full length. I added reinforcer strips (butt blocks) onto each splice to ensure full strength throughout.

Cover all raw edges with several coats of epoxy to seal them, and apply UV protectant varnish above the waterline. This constructs a box beam of immense strength with the same weight. It also provides easy drainage when you lay the boat on its side on shore, and great places to tie down cargo inside the boat.