Do not listen to those who say they cannot be DIY fixed. You use this "Super Spacer" between the panes setting the spacer about a 1/4" from the outside of the window then fill the small gap with urathane sealing caulk. The spacer can be gotten in different widths. It is important to measure and get the correct size or the repaired window will not fit back in the frame.The worst part of the job is you have to "open up" the window frame so you can get the glass panes out. First you have to pull the window assembly from the RV. The frames are a continuous piece of aluminum bent into the window's shape and joined with a splicer. Once you get the screws out of that you can spring the frame open and get the glass out. I found, rather than totally dismantling the 2 pieces of glass, I used a razor knife to cut the old spacer out at the top and bottom leaving the window panes held together by the two sides. I did help someone whose spacer adhesive was so dried out the window pretty much fell apart once we started working on it (the new spacer has adhesive on both sides) so we had to completely re-space and seal the 2 pieces of glass. If yours seem mechanically sound, with the top and bottom pieces of spacer removed, use a rag with Turtle Wax Chrome Polish on it and use a metal coat hanger to drag it back and forth inside the two panes. You need 2 people for this. This will remove the fog. Some claim the glass is "etched" but everyone I've worked on seemed to be fogged with something like calcium buildup on bathroom faucets. The chrome polish will scrub it away. Follow up with a clean rag to get rid of the polish haze. I slid the new spacer in using a screwdriver to get it 1/4" past the edge of the glass. A little tricky as you have to pull off the protective strips from the sticky spacer material . Even if the remaining old spacers seem to be failing slightly, the two new pieces will hold the window together and the urethane caulk actually does the real job of holding the window together. Dig enough of the old sealer out on the other 2 sides to let you flow a fresh coat on and totally seal the glass. Do this on a dry day. I've never had a window refog from any trapped moisture,. The Super Spacer has some desiccant in it to lock any miniscule amount of moisture away. As for the Argon gas filling they sell in new windows, it is absolutely not necessary for your DIY repair as RVs are so poorly insulated the tiny bit of help it might give is not measurable. This job is time consuming but the savings are immense. The urethane is the real workhorse here and your repair should last 10 years as long as you make sure the glass is clean when you apply it.
