"bkr" wrote:

I have a couple of different cans of varnish that I opened and dispensed
into smaller containers for use. Now the varnish has hardened in all the
various conatiners, whether sealed or not. I know it has to do with
reaction to the air, but I don't know how to prevent it. I've seen a
couple threads that I think suggested adding some other chemical to the
can that wouldn't mix with the varnish but would displace the air.

Leon wrote:

The easiest way to keep the top from skimming over is to store thc
containers upside down. There is an inert gas that you can add to the top
of the varnish in the can to displace the air in the can that helps slow the
curing process in side the can. Bloxygen is the retail name for the gas.

One of the oldest tricks going is to displace the air in the can with
propane.

Simply point an unlit propane torch down at the top of the can for a
couple of seconds before replacing can lid.

Propane is heavier than air so it will settle on top of the varnish.

HTH

Lew