Restoring old bay window.

[Michael Weber]

It's unlike the other wood double hung and wood casements on my old house that I've repaired in that it doesn't have the narrow delicate muntins. The rabbets are quite wide and deep and the muntins are pretty wide as well. I'm digging out the old glazing/caulking/cement/whatever that's been applied over the generations. There are 42 panes to do. I was thinking, since the rabbets are so deep that I could apply a thin weather strip around the parameter on the existing pane and install a second pane of glass on that before applying a glazing strip or putty to seal. Kind of a DIY storm window. Bad idea? (I'm thinking yes at the moment) Condensation issues? I've built wooden tight fitting storm windows for all the double hung and don't have condensation issues on those. Should I even think about attempting this?

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[lowell holmes]

As a retired home builder, I would have a glass company look at it.

[Tom M King]

Even a glass company will order them from a manufacturer, or at least that's the way they do it around here. You get all sorts of choices about types of glass, and insulating space. I ordered some units for custom skylights in a standing seam roof, not too long ago, and as an example, specified 1/4" bronze tempered for the outer glass, 1/2" space, and 1/4" safety glass for the inside pane.<br>
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Insulated units need to be filled with an inert gas, like Argon.<br>
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If you're going to install, and glaze them yourself, check out the glazing page on my website about my methods of glazing with Dap glazing in caulking tubes, and trimming. If you need to get it completely finished, and painted asap, I'd use Aquaglaze. There are other, more expensive glazing compounds, but these are the two I use for almost everything.<br>
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If you have more time until it absolutely has to be finished, but want to spend the least amount of actual time working on it, follow my procedure for using DAP glazing in caulking tubes. No one likes the DAP glazing in cans, but the stuff in caulking tubes is different. The only trouble is that it shrinks for at least a month, until it completely cures. I put it on thicker than needed, let it cure for a couple of months, and then trim with a sharp chisel. I just trimmed some this week that I had left on outside windows, in the worst possible location for two years, and two months, and it trimmed nice, and cleanly.<br>
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On old houses I trim by hand. If it's newer work that is better to be all perfectly the same, I use a guide board with a tapered side that I hold on top of the glazing bar to guide the chisel.<br>
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The caulking tube method takes longest overall, because of the waiting for it to finish shrinking stage, but requires the least actual time working on the sash by far.&nbsp; There is no back, and forth, or piddling with a putty knife.&nbsp; There is no putty knife in the process.<br>
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By the way, nice Bow Window.

[Tom M King]

Here are some pictures of the 26 month old DAP glazing, and being trimmed. I use a 20 degree bevel on the paring chisel, and it's really sharp. I use sharp chisels for a lot of things other than woodworking. This window is only a couple of feet off the ground, gets full sunlight half the day, and the ground underneath stays wet about half the time.

I had intended to leave it for one year, to see how it did, but forgot about it, and it went 2 years, and 2 months. It was still intact, not even cracked, and soft enough to trim almost as easily as if I had only left it a couple of months.

You can't leave Aquaglaze unpainted for long at all, or it will crack. I only use it when the job needs to be completely finished quickly, but it takes longer fiddling with a putty knife.

I didn't take another picture before I painted it, but you can see behind the chisel in the picture with the excess being trimmed off what you're left with. This also has the added benefit of leaving a nice, clean little part for the paint to adhere to the glass.

Warm the caulking up before applying it to the sash, and it will flow easier, and get down into the corner easier. In the Sun for a while in hot weather, or by a heater in colder weather.

Don't care what it looks like at first application. Just make sure you get plenty on there, because it will shrink. Per glazing bar, maybe 2 seconds to apply, and 5 seconds to trim, with a couple of months waiting in between.

[Mel Fulks]

I had not looked at the window until Tom corrected the term . It is nice. You don't see many of those.

[Lee Schierer]

I believe you are right that installing two panes of glass will result in condensation in between the panes. My original Anderson windows had double glass and we constantly had moisture in between, which ultimately led to the failure of the window.

With that said, buying 42 individual thermo pane inserts will be quite costly.

[lowell holmes]

The thought behind the post I made is that a local glass company has probably dealt with this issue.

It is worth talking to them.

https://www.google.com/search?q=glas...hrome&ie=UTF-8

[Mel Fulks]

I've never liked the double 'pain' stuff. Too much money for paltry R value. We often had people bring fogged windows in to be "cleaned and resealed". Some were shocked ,shocked! when we declined to perform in their circus. Occasionaly we
made interior shutters for accurately designed fine Georgian homes. Alas, useful shutters are not high tech.

[Tom M King]

Cost might surprise you. The insulated units I mentioned above were 2x4 feet. 1/4" bronze tempered, 1/2" space, and 1/4" safety glass. Delivered to the job, they were $238 a piece.

If it was mine, here, I would not go to the trouble for insulated glass that will last maybe 30 years. One reason I like the DAP caulking glazing compound, is because it stays soft, and is easy to get out when the time comes. I tried some commercial, $16 a tube glazing, and while it might be bullet proof, it's impossible to get it back out without tearing something else up.

Heavy curtains, or even fabric covered Polystryrene foam board, make good covers for extremely cold weather.

I use an old, Red Devil point driver to hold the panes in, whether insulated, or not, before glazing.