: You bring up some good points Erez,

: I doubt the epoxy is adding any appreciable amount of strength to the kayak.
: It’s an incomplete sandwich of sorts. I coated the frame to protect the
: wood and add strength to all the hundreds of joints and junctions. I have
: seen Spar varnish in spray can form at the mega building supply store. For
: my next kayak I plan on experimenting with this for protection from the
: elements.
: Mike Hanks latest creation in SOF is only 27 lbs. He used a lighter frame
: construction, treated the frame with an oil (I think) and covered the
: frame with a 9oz nylon. (Hope I got all that right Mike)

I decreased the frame members width, but increased the thickness, so their wasn't much of a weight savings there, if any. I used western red cedar for the frame, it is quite strong for it's weight, the way the Walrus is constructed, the cedar should be quite sufficient. I treated the frame with deck treatment, the cedar is rot resistant, so this treatment should work fine. I believe saltwater is easier on the kayak than freshwater.

I skinned the kayak with 9 oz polyester, that appears to be stronger than 14 oz canvas. It weighs less and also absorbs less of whatever coating you seal it with, giving you a double weight savings. I also used only 3 quarts of Varathane to coat the skin, I used over a gallon of paint on my previous Walrus (canvas and roof paint) that wieghed in at 33 pounds.

: My frame suffers from over build syndrome. The trestle could use 1/3 less
: diagonal braces. I also used cherry for 2 of my deck beams. I think I
: could build the same yak for 10 pounds less with some modifications and a
: synthetic skin.

: All said, it seems strange that so much weight is being added because of the
: skin. Then again, I’m constantly amazed at how light a stripped boat is
: before its fiber glassed.
: Roger

Skin kayaks can be made even lighter without sacrificing strength or durability. The cost could be in attention to construction detail, higher tech (higher cost) materials, or more careful design.

Mike