We did some mould making yesterday who h was a bit of a disaster with the polyurethane positives. We didn’t put mold release and probably left it for too long. The positives didn’t come out from the mould. We could salvage only half.
We also lost a few mould because I stupidly pushed everything while opening the catalyst ( I think) and tried to fix it by random movement pair pouring silicone
This silicone had a fruity ester type smell. The catalyst smells of homeopathic medicine. and the silicone doesnt seem to give out formaldehyde after polymerization.