I have some 25 year-old double-hung windows that supposedly have double vacuum glass for the glazing. They have been cloudy between the two pieces for many years, but I didn't get around to working on them until yesterday. I removed one of the glass assemblies to see how thick they were and the exact dimentsions so I could order some replacement glass units from my local glass store. I have used the store to prefabricate glass to replace some other window units about 9 years ago with great results. As I was removing the two layers of glass from the aluminum frame that separated them, the aluminum frame separated at one of the corners and a zillion (well maybe only a million) tiny white beads came out of the frame. They were about the size of sprinkles on chocolate mints. I am guessing that maybe the windows weren't really vacuum sealed, but depended on the beads to absorb any moisture that headed in their direction.
Does anyone have any experience with these types of windows they can share?