[hypoxia]

I think I came across the reason the moveable flush windows lose their seal and fog.  Auto Glass Boss resealed all of my glass.  A year later I had them clean up some sealant that had come out.  It was mentioned that it looked like the windows that open were beginning to do the same thing.  After some discussion I realized there are two problems.  First, the sealant Hehr uses is inferior which affects the fixed as well as the moveable (opening) dual pane glass.  Second is the long term problem even after it is repaired with a quality sealant.  The foam that seals the moveable panels get pushed in and loses its resiliency.  Then you have to really crank down to tighten the windows so they don't flap around while driving.  That causes the outer glass pane to contact the rubber bushings and push the outer pane out from the inner pane thus pushing it away from the sealant.  See my photo.

   

[hypoxia]

On the photo I posted, the foam pieces that the outer glass pushes against, do all of you have those pieces? The thought process is that if we were to remove those pieces then that would allow the inner pane to contact the foam without pushing out the outer glass.

[hypoxia]

Perhaps no one else has those pieces. I removed them and now I can run a thin card between the outer pane and the window frame. That should resolve that problem

[Jack Houpe]

Jim when I was in the service 50 years ago we use to purge our instruments in aircraft with nitrogen to prevent them from fogging up going through massive rapid temp changes. Would it be possible to use a hypodermic needle as a means to pull a vacuum then purge with nitrogen? Or even put a very low pressure on it to find the leak then seal then vacuum and purge with nitrogen.

[hypoxia]

The movable windows that open are easily removed and repaired but the fixed glass access to the seal would be difficult.  There is no frame to support the glass.  It was explained to me the temperature, pressure changes and wind buffeting are constantly working on the adhesive sealant.  If the glass gets loose from the sealant it can fall off going down the road.  I had one small window panel that was loose & I had to tape it to the inner pane to avoid losing it.

I would be afraid to mess with the seal for fear of causing problems.  Mine are all sealed now, hopefully they last a while.  I do travel at altitudes below sea level and the highest passes 11,000' + so the window sealant gets a workout.

They all do have 78% nitrogen in them