> Any chemists out there to explain why it's so hit-and-miss?
>I haven't found it to be hit-or-miss, despite owning and/or using a
>couple of hundred bottles of the stuff.
Neither have I. I'm no chemist, but in my experience, Polly Scale and the old Aeromaster range are the most reliable acrylic model paints. Others swear by Gunze Sangyo and Tamiya, but I've had trouble with them crazing or not drying, even when taking reasonable preventive measures.
If
>there ever was a Polly S thinner,it would probably not work with Polly Scale paints.
There was, and, in my experience, it does. While the safest bet is to use the proprietary thinner, I've also used Model Master acrylic thinner, windshield and window cleaners, and distilled water to thin Polly Scale for airbrushing. All have yielded satisfactory results.
My infrequent problems with Polly Scale 'clumping' are likely due to not cleaning the bottle or cap threads completely.
Scott G. Welch