I am using just regular 'thinner' from the hardware store with Randolph Clear Non-Tautening dope thinned 50-50, as well as with the same mix with a tablespoon of cornstarch as a sanding sealer and have not had any problems. I would just recommend that you mix up a small batch at first and try it to see how it goes. This is what I had done, and as a matter of fact, I still mix up only a max of 4oz at a time myself as I have only 1/2a models.