Quote Originally Posted by Goemon View Post
Regular room temp cure epoxy is not massively stable in high temperatures. It can become soft if left in the car on a hot day. Mixing it with sand /gravel helps a little but the best approach is to heat cure the resin or post cure. You can do this as a diy job by building a make-shift oven around your mold using sheet metal. You can then heat it with a plug in heat element from a BBQ smoker ($50 on ebay).
....
How long do you need to post cure and at what temperature?

Kind regards,