Opened a new can of Schooner varnish about a month ago for use on my Wood Duck 10. After a couple of weeks, the varnish in the tightly closed can started to film over and then to gel, making it very difficult to use even after filtering with thin wire mesh.  I am now close to the bottom of the can, and what is left is so mucked up it is useless.

Given the price per quart, this is disturbing.  When I was building ship models, I bought varnish that would harden within a few weeks.  As I used the varnish, I placed very clean rocks in the bottle to eliminate the air. I added more stones as the level went down, and that varnish is still fine (a year later).  Wonder if this would work as well with Schooner varnish.  Any thoughts?

 Rich