RV Repair: Roof Coating, aluminum roof, ceiling assembly

Question
Hello,
I own a 36 ft trailer with a aluminum roof. I am wanting to coat the roof to prevent leakage. what should i use? The trailer is about 12 yrs old. also around all the vents, ac cover etc there is a lot of sealant around them. should i scrape this off and reseal them or just cover them over with the roof coating? if you recomend scrapeing and resealing what should i use for this?
thanks a lot
George Osing

Answer
George
I would not recommend coating the entire roof.This creates more of problem than you started with. once you coat the entire roof you have no original surface to adhere to in the future. The best way is to take a putty knife(I prefer a 1 & 2" sharpened just a little bit)and start scraping.First get all of the loose material off and cut into any cracks an bevel them out. Use a good heavy duty cleaner to clean all areas that will have new sealant applied to them. I prefer to have the new sealant go out as far as needed to get to clean metal. I usually run tape lines to seal up to around all vents and accessories. I like to use  Geocel Pro-flex. Not every store will have this product it is a little exspensive.Pro flex stays pliable and goes on a little thicker.It does not tend to crack as early as other products.While doing the roof I would also pull the interior ceiling assembly off of your air conditioner to take a look at the gasket. If you see any trails of water you will need to pull it off and re-set it as well. Plan on spending the better part of a day for this project.
Thanks, Chad
Truline RV