great stuff low expansion foam. red can. I've used it for all kinds of adhesive use. run a small bead and stick it up. then tape it. you may need to reapply pressure after 10-15 min. a few dabs here and there to tack it. I've used plastic bags to help form it. then peel them off after it dries.
acetone clean up. but keep it away from the stryofoam
I have re-arrainged the foam blocks in my hull cavities to make a lot more room without removing the blocks from the boat like some do, and I used the "great stuff" low expansion foam for lightly tacking the blocks in place so they stay put, without any bad effects or reactions. it did not seem to affect the styrofoam in any way other than gluing to it...
for anyone doing this, I would recommend that you not get carried away with the trigger and dont let the canned foam get on the hull too much.... you never know when you may need to remove some of the blocks to gain access so you can make a hull repair or rebed a piece of hardware... the canned foam is a terrible thing to have to remove, cuz its tougher than you are....
considering my experience with it, my opinion would be that the "great stuff" brand of canned foam is safe to use with styrofoam...