Bulge in exterior fiberglass...

cannesdo wrote:
What else do I want to use the silicone on? I mentioned it before only because that's what's sealing the outside of my kitchen windows and I simply noted that it appeared to be in good condition, no breaches from the outside that I could see. I asked a lot of people about the screws and all recommended the silicone to waterproof them -- literally half a dozen people. No other suggestions were made -- and one of the guys was a marine hardware supplier in Puget Sound. I don't just walk into Walmart when there's a problem and find something sticky and call it a day.

You're correct, stick with the local advice and forego some of this internet stuff. Remember being an internet expert and having real life working knowledge for an area are two completely different things.

On your rubber roof you need to use Dicor (all RV places will have it) you also have the choice of using a sticky tape (Eternabond) but at this point I wouldn't. Just reseal the roof with Dicor, I would also wait to get to the desert to do the whole roof job. If you're in a humid area you'll be fighting the dew (and salt) for most the day on the roof. That roof has to be completely dry and clean to ensure a good seal. Right now all you have is a small 10 inch section that needs attention, no need to feel like the whole thing is going to fail any minute. This was just your wake up call that you waited way too long to reseal the roof. You survived it with minimal damage.

For non rubber roof sealing I like the most expensive tube of "GE II silicone for doors and windows." It is what they use in areas that have high heat (like AZ.) This caulk seems not to melt when the temps get extremely high. Make sure it is the very best that GE makes though. Use that caulk on all non rubber roof areas. Again thin is good, don't glob it on thinking the seal will be better, it won't.

Good luck, and don't lose a lot of sleep over this, you just left the ranks of internet experts, and got some real world working knowledge thats all. See you on the road and safe travels.

On edit:

BTW, most of us near salt water do swap out the screws for SS, but we only do a handful now and then since it's a big job. What I like to do is use a small square of butyl tape over the hole then drive the new SS screw thru it. I then peel off the excess tape from the fiberglass with my finger. Can't imagine how water would enter doing it that way. Again good luck.