I have a 2001 Fleetwood Mallard. I would like to use roof magic to coat this alpha roof. I bought this 5th wheel used 7 years ago and am unclear about what has been used to coat the roof before. I am concerned what if the previous owners may have used some kind of coating that possibly had silicone in it. What would you recommend to test/ adhesion. I have used Eternabond on this roof and it sticks very well. Appreciate your reply. Thank you, cheri