Hello-I have found lots of good information on this forum. I am currently in the middle of my oven/outdoor kitchen project. I am getting ready to cast my oven from homebrew refractory. I have gotten good info from David S on this subject. What I need to know is-what can I use for a release agent between my mold and the refractory cement? Will Vaseline(petroleum jelly) work? Or will this effect my cooking from the residue left behind, or effect the refractory cement? Your advice is valued. Thank you.