I contacted the Insulfoam plant in Ohio and they won’t sell to me. The best I’ve been able to do so far is $5.60 cu.ft. from a local EPS manufacturer through a local distributor. The main catch is the size block I have to purchase. Anything over 8’ in length and you get charged for 16’. So I priced a 16’x2’x1’ block of 2lb and it came to $179.20. Figuring on cutting out the rocker vs. bending the blank, I would think I could get at least 3 longboards out of it, ~12’,~10’ and ~8’, or is bending 3.5" thick foam to the desired rocker possible? If it is I may be able to get another 8’ board out of it , but I don’t need anything shorter.
I was also wondering about stringer wood. Will cedar work well for a main stringer? I know I can get rough sawn cedar boards 1x6,12’ locally, cut the stringer out and rip it to thickness on the table saw.
I think I’m trying to make this too difficult.