Are these old bottles of the solvent-based Floquil? You confused me when you said "enamel". I have never used any Floquil other than that old stuff, and I thin it with Xylol, which you can buy at paint stores or places like Home Depot in quart cans. You also buy "Xylene". If you use it, expect horrible vapors, so open lots of windows, paint outside, or use a respirator and/or paint booth with exhaust fan. For me, since I am only ever painting one or two pieces on the rare times I airbrush at all, I just open the windows and doors, do it in the garage, and get the heck out of there when I'm done until it has a chance to fully air out.
