1 of 1 people found this helpful
Check Radio Shack (or some other supplier of electronics for hobbyists) for brush-on liquid insulation coating. It's opaque, very thick and applies easily. Non-conductive. Once it's cured, it can be removed by simply peeling it off.
Mine is from CG Electronics (Carl Goldberg) and the part number is 10-1762. Comes in s 60ml bottle, which appears to be a lifetime supply.