I mostly use Model Master enamels. I recently had a very bad experience with RAF Dark Green and Sky "S". The green was a new bottle I purchased at the last Squadron Scalefest and Open House. It is unusually thick, had a peculiar smell unlike the other MM enamels, and, when sprayed, would somehow seem to separate from the thinner, leaving me with more-or-less pure thinner coming through the brush for lengthy intervals. I had not had this problem since I quit using Aeromaster paints. I thinned the Sky (aslo a freshly opened bottle) 40 thinner/15 paint to do some fine edgework, and had, for the first time with this brand, a hell of a time clogging and, like the green, paint separation and pure thinner coming through the brush. I wound up having to hand-paint many areas because of the paint's poor performance. I used Testor's thinner, although from the red "general application" can as opposed the black MM can, which is usually what I use. I use a Paasche "H" with the #3 tip and a canister compressor at 12lbs. PSI. Except when I was using Aeromaster paint, I have always gotten excellent results with thes methods.
I just read an article by an author on Internet Modeler who says he uses MM enamels and Tamiya acrylics and uses Gunze Self-Leveling Thinner, which he considers the best air brush thinner around, with everything. It's lacquer-based. Has anyone used it with enamels to know if it will work well with them? Does anyone have any ideas on whether it will help to avoid the problems I just had? I'd like to hear experience talk before I plunge for the price of the thinner.