LOL, ain't that the truth.
I put some foam into the boat last night, and found (as usual) that it'll be a learning process. My first attempt was using 1 large piece of foam - approx 18" x 6'4" - up against the hull, in the area under the stringer, down to the level of the original vberth. This taught me that it will be easier to do this with smaller panels - say 2' max dimension. It also taught me to cut the foam outside of the boat, in the daytime - little tiny pieces of foam get *everywhere* when cutting, even with a razor knife. For this "exploratory foaming", I am using 'Cellofoam' brand panels - 3/4" thick EPS, it has a mylar radiant heat barrier on one side, and is only US$10 for a 4'x8' sheet. I'm using 4 sheets to make a first run at the process. This foam will probably all be removed in favor of pink/blue foam for the end product.
I also made a small test panel of my "foamboard plywood" concept (pink foam sheathed with wood) to see how strong that combo is likely to be, and have to say I am *very* pleasantly surprised. I recommend that anybody adding structure into their boat consider this as a light, strong alternative to conventional plywood. I sandwiched the foam using Luaun door skin material - it comes in 1/8"x3'x7' - and it is very light and very stiff. The door skin material can be cut with a razor knife, too, which really cuts down on dust and noise. I think another advantage is that I will be able to use it like and instead of cardboard for laying out the size and shape of the bulkheads inside. Cut the Luaun to the right size, and I have 1 skin which is also the pattern for the other skin as well as the foam core...
I looked at all the adhesives at Lowes and Home Despot trying to find one compatible with the foam. For right now, I don't want a permanent solution, so I eventually went with "Duro All-Purpose Spray Adhesive" which claimed that it would work with foam board. It does, but only if you spray it very lightly and quickly - otherwise some ingredient in the stuff literally eats the foam up. When I put the foam in for good, I am thinking that I will just use 4200, spread with a squeegee/trowel...