How do I make professional grade double pane glass at home?

Question

I've been shopping around and no one near me will do Argon filled double pane and only one place will do a vacuum. The price seemed astronomically high considering I can buy the glass and the local hardware store (single pane 2x amount to make double pane) for ~1/10 of the cost. So ranting aside, what is the best way to make double pane glass / window inserts from single pane glass? I was thinking about using something easy like a few 1/4" plastic tile spacers to keep a uniform spacing with weight or light clamp then applying heavy silicone bead to everywhere but the spacers, coming back later to fill in all but one or two of the spacer holes. Do a good inspection and cleaning if necessary, plug to have one hole left and then pulling a vacuum to ~7-10psi (~5 psi vacuum from ambient). Last hole (vacuum hole) will have to be plugged/corked with something else then silicone to ensure longevity.

My project calls for 24 ~8.5"x11" inserts, trying to weigh in my approx. time to build these and that I already have vacuum pump, I could have a 50% success rate and still save money so if it at all possible to do this at home/shop I'm going with that option.

Answer 1

I would look for a supplier that would ship you the bare panes and build the frames yourself. I doubt you could manage a proper seal. Look how many tries Edison went through developing a vacuum light bulb. Although, even just air insulated double glass would be better than single pane. Unless it stays sealed, condensation will be a problem

You may have to order thermal panes from a glass shop, who then gets them from a manufacturer, Should still be cheaper than buying complete replacement windows.

Answer 2

Glazing manufacturers have spent decades perfecting a spacer system that does not eventually leak and condense. They still haven't completely perfected it, though they are much better than 20 years ago. There is no way you're going to put together a system that does not eventually leak, especially with a vacuum. You'll have a better chance with inert gas, but I'm not convinced even professional argon filled glazing stays argon filled years later. It's not that I doubt your fabrication skills, it's just that it's a very difficult problem to address.

For all the time and effort spent assembling a window system, it's worth buying professionally built glazing units. If you want to save some money, forgo the argon filled and simply get dual glazed units with a low-E coating. IMO, these offer decent thermal performance and good value.