A casting tip from an amature

[davehal9000]

For years I've on and off tired various brands of molding and casting materials. I never had much luck with them, getting usable molds but almost no luck in getting a usable cast.

The other day I picked up a set from Micro Mark. My first mold turned out great, but my casts all had uncured spots on them, no matter how long I let them dry. Typical of past attempts as well.

The I remembered a lesson I learned making Halloween props using fiberglass resin; I took a Q-tip and scrubbed down the mold with acetone. My casts have been flawless ever since. May be something to try if you're having similar problems.