Foam trapezoids here. I ripped them on a table saw. Ok, my dad, the furniture maker did. On the 25, I tabbed them in with 2 layers of 1708 in vinylester.
There is a recipe (scantling rule) for this but if you have the foam in there, it would be difficult to use too much tabbing. I wouldn't worry about using 2 layers of 1708. Getting it to stick to the vertical runs is fun.
http://www.classicseacraft.com/commu...t=25405&page=9
Not trying to fit them blind, on your belly, while under the deck will be easier.
