crystalized epoxy: can it be revived?

[Greg G]

Hey forumites I went to use some epoxy last night to do a few butt block joints on my gloucester light dory and found my epoxy ( the base stuff not the hardner)had seperated and crystalized. The stuff has been sitting for about five years, been frozen and thawed many times ( it lives in the garage). Is there any way to resurect it? I was counting on using it to seal, glass and finish the dory. Any insight into this situation would be appreciated.

[thechemist]

Hey, no problem. All pure compounds freeze, and many epoxies purify themselves by freezing, since the melting point of the pure compound is above room temperature.

Cover it, loosen the lid, and place in [but not fully immersed...] a pot of recently -boiled water. Set the pot on an insulating pad, since we don't want this to cool down too fast. Drape a towel over it, and leave it to sit overnight. That is usually enough to remelt it.

It is VITAL that you remix the stuff, since there are usually other compounds [epoxies, but ones that freeze WAY below room temperature] in their formulation, and you want to reconstitute it to whatever your supplier intended.

[Greg G]

Hey chemist, thanks for the info. I will give it a try on my next days off. I'll let you know how I made out with it. I'm relieved to know I won't have to throw it out.Thanks again.

[Dave Carnell]

In my experience, it will take a lot more heating than that. I put a gallon jug of solidified epoxy in a pan of water and put it in the oven set at its lowest temperature, which is about 150°F. It takes several hours to melt completely to liquid.

[Tom Lathrop]

Dave, Chemist,

I agree with both of you. I have had occasions where it was sufficient just to hold the lightly crystalized resin jug under a hot water tap for a few minutes but that is rare. For well crystalized resin like is being described, Dave is right and it will be necessary to hold the temperature at somewhere near Dave's suggestion for a lot longer than just cooling down time.

Some resins crystalize much more easily than others but I've not found any that won't, in spite of claims to the contrary.

[Greg G]

Well, tonight I got to try the cure. It worked like a charm.I boiled a canning pot full of water and filled a five gallon pail with it and floated my jug of seperated epoxy in it wrapping the pail with an old quilt. We left for a family dinner,you know, lots of beers eats etc. And when we got back home, done. Not a crystal to be seen. Thanks for the advice guys. I will post some pictures of DARLING DORY when I'm done.