[wessellsp]

It is a bad idea to heat the glycol too much. What I do is to add the ingredients to room temperature gycol and then warm the mixture with stirring until the solids dissolve.

Well, I made up a new batch of MC following Jerry's method. I never let the solution get above 120F. Same outcome with TMY-2 - high B+F for the constant agitation test and fog for the EMA test. BTW, I mixed a batch of Pyrocat-M and used it in a constant agitation test, which resulted in very clean negatives. This implies that the metol I am using is OK and seems to isolate the ascorbic acid as the problem, but who knows?