3M 5200 Marine Sealant et al
I currently go over my camper religiously looking for chances of leakage at least every six months. Seams on the roof, windows, etc. are checked for any signs of cracked sealant or separation. I treat...
Forum Discussion
HMS Beagle wrote:
I personally don't like butyl tape. It doesn't harden, but it doesn't cure or stick to anything either. When it gets hot, it oozes out of the flange making a mess, and now it is gone when things cool again and you've got no pressure on the seal. I've seen many things sealed with butyl fail, including the shower skylight that I am right now fixing on my Bigfoot.
There is NOTHING that will give a "forever" water tight seal except plastic welding and just like metal welding, it only can be done between the same types of plastic ! (TPO is "welded" at its seams and they have pre-formed inside and outside corners.)
Butyl is best used where the window is held in place by other mechanical means and can be removed so that the butyl can be replaced. If it is oozing out, the item was clamped too tightly.
