Thanks for posting this thread David, very timely. I need to do a chamber casting and have been playing with the mould design software on Mountain Moulds website also. I was going to order some cerosafe, too expensive for the number of times I'm likely to use it. I'll trott off to the Chemist after the long weekend and buy some Sulpher. It should be cheap enough volume wise for me to do several chamber castings just in case I mess one up and not be drastically out of pocket.