My metal sliding glass door works great but there is dust/dirt on the inside of the thermal panes - really affects the view. Can the glass be separated, cleaned and resealed? I've never noticed condensation but have only been in 1970s house for 1 year. Thanks in advance!

Lori, I ran into the same problem and found no answer other than to replace the window. My window appeared fogged for a very long time and because of some pressure to the door (2 very large Shepards playing) it crumbled. I was shocked to find that the price for replacement of the glass was minimal. I don't know if this is the norm or just dumb luck but the door was repared over 2 yrs ago and still looks fine.

There are some companies who claim to be able to fix bad thermopanes but I make a nice $$$ changing them out. You are probably out of warranty but some did offer 50 years so check. YouTube - Get the Fog Out - Thermopane Window Repair Rochester NY (http://www.youtube.com/watch?v=1_DP8XoC09s)

Lori, I should have mentioned that I only replaced the glass, not the entire metal frame, etc.