I've been casting for a couple of years now and finally settled on materials that work for me. However the last couple of molds I made have been fusing with the resin after only a couple of casts. Tiny bits of silicone seem to bond with the plastic and I end up with small holes/defects in the molds. This never used to happen, and I'm using the same types of silicone and resin as usual, and haven't changed anything about my process as far as I know.
Does anybody know what the chief causes of this kind of bonding are? i.e. temperature, de-mold time, wrong silicone/hardner ratios, etc? There's nothing more annoying (and expensive) than losing a perfect mold and I'm struggling to figure out what's suddenly going wrong.