I might!
Just as
@waltr said, I haven't used balancing clear as it's own coat. But, I did get a bad bottle once. It was thicker than my first bottle of the stuff, not quite a paste but visibly thicker than the previous bottle was. This bottle was cursed; anything I added it to clogged the airbrush. Eventually I threw it out. The next bottle I got was just fine, same consistency as the first bottle I had.
I believe that under some conditions, some of the solvent that is used in these paints exits faster than usual. While mostly water based, there is some sort of alcohol or other organic mixed in at some percentage. I've noticed that my older bottles now have a "sucked in" appearance to them; I'm pretty sure this is due to gradual (over 5+ years) evaporation of water and solvent resulting in higher paint concentration. Sometimes mixing in some reducer helps, other times not. I need to figure out what the solvent moiety consists of and see if adding some of that helps. Sadly, I probably have a couple dozen bottles of paint that isn't worth using, spanning Createx/Wicked Colors/AutoAir/Auto-Borne.
More to the current point: if you can thin the balancing clear sufficiently to paint it over the edges with a brush, do that. I never spray the stuff to seal tape; I paint it on with a fine brush to do so. Actually, while I have used balancing clear to seal tape, I usually use Transparent Base for this purpose. It's thinner, and when brushed on sparingly, you don't see any brush marks on the parts that remain after pulling the masking.
Good luck, and keep us updated.
Edit: good page with links to TDS for thinners. Different reducers have different solvents, but the standard 4011 reducer probably has the same solvent as the paints: propylene glycol monomethyl ether acetate. OK, not something you'll find at the hardware store.
