Hello all, Was thinking of trying to carve foam to make rock faces on a section that would have been blasted out, but came up with a cleaner, much easier and very satisfying way of making. Simply crumple up a chunk of tin foil then stretch it out again roll up the sides and poor in some plaster of paris mixed a little runny, pop in the oven for 10 mins or so to speed drying and let sit for a couple of hours. Peel of the tinfoil and Presto. I made some in a curved shape to go around a bend, cuts well with a hacksaw blade and easy to join together and you can make really course or smooth if you prefer. and no two sections of mold are ever the same.And you can make plenty of it in 15 min. When joining together spread thick plaster between joints and use a ball of tinfoil to texture. Don't know if this is a already established method or not but I though the tinfoil had the right shape and was really impressed. Well thats my two bits and I hope someone lets me know what they think. Johnny.