@DelphiHelper (oops on 1st reply!) I actually went ahead & tried it (I'm so impatient when I get an idea) and it turned out beautifully. I used the rake I had purchased from Delphi, and followed various instructions I had found online. While none of them discussed using molds specifically, I followed the rule of ensuring several coats of kiln wash, and I made sure not to rake too deep. Also kept my intrusion quick then flash vented to 1200 before ramping down to anneal. Thanks!

@DelphiHelper

Does anyone know how hot you can fire a casting mold? I'm thinking about trying combing in a mold, but I'm concerned about how hot I have to go for the combing... I don't want to damage the mold.