Pictures of rebedding back window. This is a pretty easy job in the rv site how-to videos; devil, as usual, is in the details. This window was leaking about two cups of water from the upper right in a heavy rain. Cushions, memory foam and bed linen on the rear decks removed since the rally
in Williamsport PA in early July. After removing the clamp ring inside, I had to insert a 1" putty knife all around the flange to break it free. Saw why when I got it out: not only a layer of putty tape but also a second layer of butyl at the top applied right over the original putty tape. Also a heavy bead of very hard linseed oil-caulk thrown in there where it did absolutely nothing except make removal and cleanup harder.
I didn't take the pix until the bedding flange was all cleaned up. I should have taken more pix but thunderstorms on the way and I wanted to finish. A couple of hints to those who like myself, haven't done this, but will in future.
1) Bestine is a very good solvent for final cleanup of mating surfaces of trailer and window flange after the bulk of putty/other goo has been scraped offl
2) When you apply the Butyl (and ONLY Butyl) tape to the window flange, remove the paper separator as you go (and particularly rounding corners) to get it accurately aligned. I know fingers stick to it but not if you wet them in a bowl of water as you go. Yeh, you guessed it; I just licked mine.
3) The channel in the window frame extrusion which catches the sheet metal screws thru the interior clamp ring is narrow and soft. It is easy to cock the direction of the screw and completely miss the channel. I could see that this had happened in three locations while the window was out. The channel was deformed and pinched together in two locations and I pried these areas open. Every location where a screw doesn't grab is a place where compression on the Butyl gasket is reduced.
4) Do not use screws longer than the original but don't be afraid to move up one size (say #10 for #8) if the 8s don't catch.
5) Wet the mating surface of the trailer before placing window in the opening. If you have some slack, the butyl will not stick and you have some time to get it precisely where you want it with even bearing all round. (Pix indicate that the rough opening was a bit irregular and the area of bearing scant right where I had the leak (upper right). I'd like to attribute this to those fine old Escondido paesan (farmer) working methods so I will. This points up that "humoring" the window frame up a bit so that bearing at top was maximized was the way to go in this case.