Is regular metal ok to use as a soap mold?
No, the only acceptable type of metal that can be used in association with soapmaking is Stainless steel, other metals such as aluminum have the potential to oxidize when in contact with raw soap or lye and produce hydrogen gas as a product of the chemical reaction that takes place from coming into contact with such elements. This could result in a potentially hazardous situation as hydrogen gas is extremely flammable.