I have a large bottle of Pro Kote high build resin that has never been opened but is as hard as candle wax. It's been kept in a climate-controled environment. Can anyone tell me what happened to it and can it be returned to a liquid form that is still useable?

Put it in a hot water bath until liquid again.
What does climate controled environ. mean?? What was temperture?
Herb

The resin will crystalize when cool. warming will make it fluid again without harm.

Herb, it is kept in my rod building room. It has AC in summer and heat in the winter. It never gets below 70 in the room.

It's common with just about any epoxy on the market. Sit the bottle in some very hot water and let it sit for awhile. If the water cools before the resin returns to normal, repeat.

It is also possible to do the same thing with a microwave. Loosen the cap and give the bottle a few 5 or 6 second bursts.

I'd go the hot water route if you have the time.

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Thanks everyone.