<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Dick N.:
My question is cleaning before applying the tape. Some use windex and others use a non- chlorinated formula brake cleaner, which I believe Eternabonds recommends. I bought this cleaner at Wal-Mart called Prestone heavy duty brake parts cleaner. Is this ok to use????? It's fast drying and I tried a little on a rag and clearned some metal and it works fine. All I have left to do is cut the 4" in half. </div></BLOCKQUOTE>
First, determine what kind of sealant Winnebago has used on your particular roof. Spray a *little* bit of brake cleaner on the sealant. If it dissolves the sealant, then they've probably used some sort of crappy stuff like Dicor 501 Lap Sealand; and it's just a matter of time before it *all* has to be cleaned out and replaced with a more appropriate sealant.
If the sealant doesn't dissolve, then they've probably used a polyurethane sealant which should last for years; and their would be no useful purpose served by replacing it.
If your sealant is soluable, then the old stuff should be cleaned out in it's entirety, because the foundation for the new sealant won't provide any better adhesion than provided by the old sealant.
I would certainly NOT recommend using brake cleaner on the roof joint, or any other structure that is constructed with styrofoam. Spray a piece of styrofoam with brake cleaner, and the reason will be immediately apparent; not to mention what it will do to the adhesives used to bond the fiberglass to the underlay. Any solvent which includes a BTX (Benzine, Toluene or Xylene) should be avoided, notwithstanding that evaporate before it has had a chance to do it's job.
Paint thinner (not lacquer) will still do quite an effective job, and because it is less volatile, it will remain on the surface for a longer period without evaporating. When I did my roof, after cutting away the old sealant, I cleaned the channel with a washcloth soaked with paint thinner, wrapped around a paint stir stick.
For sealant, I used a household grade of polyurethane sealant; although 3M marine grade polyurethane sealants are substantially superior. The household grade stuff seems to okay though. I did my roof back in 2002, and it isn't showing any signs of failure.
The thing I like about polyurethane, is that it has tremendous adhesive characteristics, as well elasticity.