About 9 months ago I mixed a small batch of 2/3 varnish (Behlen's rock
hard) and 1/3 pure tung oil. I used it a couple of times this past
week and it worked fine -- dried fine and in the can looked like it did
when I mixed it back in November. When I opened the can yesterday to
put on a third coat, the mix had turned to the consistency of jello.
It's in a small (pint), new paint can from a paint store. The can is
about 1/4 full.

Any ideas what's happening? Is this normal? The seperate containers
of varnish and tung oil that I mixed this from seem to be fine.
Neither one of them has turned to gel.