basically just smear it on. it kind of self levels itself if you do it fairly quick. you don't want to be working it around too much or it will start to set up. works very well but adds quite a bit of weight. not too much of an issue in a 20 lb plus rc. anyway this typically wont prevent cracking or breaks just prolongs the body life a bit. what i would do is just wait until it breaks or cracks and repair it accordingly.
MCD Race Runner.
Have you guys heard of the tape method? I might do that around the gears and parts that rub. I figured it would not prevent the shell from cracking, I am mainly looking for something that won't scratch the paint off.