I preped mine very well and applied the Zep 2 years ago. We spent the last two winters in Florida but spent the summers in the desert southwest. Mine is peeling badly on all the dark color sections of the motorhome, the white still looks great. I put on about six coats so I believe it was too thick and cracked because of the hot dark colored sections. I am now trying to get it off and yes it is a hard job. The stripper softens the paint and did ruin part of one of my doors so I am back to ammonia only which is much slower. I am not sure at this point whether I will reapply two coats or just leave it off. I would not recommend using it if you plan to spend any time in the extreme temperatures of the desert.