Over the winter one of my epoxy pump reservoirs turned into a block of grainy crystallized epoxy. Normally the remedy is putting the epoxy container in a double pot boiler and warming it up until it liquifies. Since my resin is stored in a pump reservoir unit, instead of a jug, I couldn't drop it in a double pot. Instead, I took the reservoir lid off and warmed the chunk with a heat gun while prying at it with a wood paint stirrer. It didn't take long before the heat started melting the block. About a half hour of constant heat and stirring restored the epoxy to a new like state. Thought I'd pass this on because I know over the years folks have asked about what to do with crystallized resin. The simple solution is heat and stir.