Well, so far so good. For people who have wondered but didn't want to take one for the team, I'm plans building a hand launch R/C plane called a Crazy Thing by Precision Aero. If you go on their website, the picture they use for the Crazy Thing is also one of my airplanes built more than 15 years ago. The Monokote still looks good but is becoming a little fragile and there are always a few small wrinkles that pop up now and then. I wanted to play with Koverall again. I did two airplanes many years ago using Poly Fiber materials. This time I'm trying dope for the first time ever. so, this Crazy Thing is fiberglass and thinned West System epoxy on the solid surfaces and Sig Koverall on the open panel wings.
About compatibility. The Sig Koverall was applied using Sig Stix-It straight out of the can. The base coats are Sig clear nitrate dope. I'm thinning it with MEK without issue. Over that went Brodak Sanding sealer which is butyrate dope and talc. I thinned that with MEK as well. I'm into the color coat now. I wanted a translucent color on the solid fiberglassed balsa surfaces to partially mask the wood but still let it show through a little. To do that I mixed about 3 parts sanding sealer with 1 part Brodak colored dope. I thinned it all with MEK then added retarder to slow down the drying time. MEK dries fast and spraying speeds that up even more hence the retarder which I found necessary even when brushing. The wings will be a solid version of the color thinned with MEK and Brodak retarder to prevent blushing.
I am confident in the compatibility of MEK with these materials. It's even listed as an ingredient so how can it not be compatible?