I know these questions get asked all the time but here is another one. Is this ingot mold http://www.amazon.com/Wilton-Aluminu...ref=pd_sim_k_2 a good one to use? It's aluminum and looks like to me that it should work good as long as it can take the heat. What do you all think? It's a six cavity for less than the price of the 4 cavity Lyman. Is it true that you can't use the non stick coated steel pans? If so why?