Window glazing

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Window glazing

Post by Tujo »

I started on reglazing the 10 window sashes from my back porch (the now infamous pocket windows). They are 6 pane windows. Tonight I worked for almost 2 hours... ...and didn't even get the glass out of one. I was using a heat gun (on low, the gun is kinda busted and only works on low) to heat up the putty then I was trying to get it out with a scraper. I broke 2 panes of glass (it's okay, I'm planning on ordering a stack of panes...), but then I got a bit smarter about it and changed the way I was working - heating up the wood, not the glass. It's still taking too long, for a couple of reasons. The glass is almost exactly the size of the opening - virtually no gap. Also, the glass was never bedded, it only has glazing on the outside (seems to make the glass very fragile).

Has anybody done a lot of glazing? Any advice?

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Post by brick1101 »

Doing windows is right up there with my favourite things to having root canals!
I have had good luck using a Prazi putty chaser ... 5-2,C,1660
It takes a bit of practice to get used to, but if the putty is dried out, this tool chips it all out real fast. I did some 20+ windows over the years using that tool. They are 6 over 1.
Be sure to prime the bare wood before reputtying......

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Post by angolito »

tujo. well, i had 1/1 so i guess i got off easy. i really am weird......i love glazing.

how bad and dried out is the glazing? according to the restoration guidelines, it is not advised to replace all glazing. its a good excuse anyway.

i didn't attack the glazing with a heat gun. try putting a glob of stripper on the bead, cover it and leave it overnight. softens it right up, no *sweat*.

if you are very careful you can use a razor scraper for the putty. if you have wavy glass it won't get every bit in the "valleys" but sure doesn't scratch the glass any worse than a scraper.

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Post by Tujo »

Some of the glazing is fine, some (especially along the bottom edge) is cracked, loose or falling out. I assume though that if I do a pane of glass, I should do it all the way? Or do I just remove the loose glazing and replace it? Even if I just only do the panes that look like they need it I could cut the work load in half at least. Also, what stripper did you use?

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Post by jeepnstein »

I use plain old MEK stripper and get good results. It usually only takes an hour or so, which is still faster than the darned heat gun. You have alot less breakage and it also helps break the bond of the putty used to bed the glass.

If the glazing is solid in spots you can get away with just doing the bad spots but the repair won't last as long. Some times one can just scrape the loose away with a carbide paint scraper and fill it all back in smooth.

I had a fellow tell me once that paraffin lamp oil will soften the glazing very quickly. Since I always have stripper on hand but never seem to have lamp oil I've not tested that one out yet.

Good Luck,

"Pure Stinking Genius, that's what that is. Hey, can someone get me a fire extinguisher?"

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Post by HB »

Here's a couple of tips to help with putty removal.

Make yourself a heat shield to protect the glass. A piece of cardboard or luann flooring cut to the size of the panes and wrapped in foil works great.

The glass cracks because it;s being heated unevenly, only along one edge. It may help to heat the entire pane of glass just a little bit before concentrating on the putty.

You could also brush the putty with boiled linseed oil and then let it absorb it overnight. It whould help to soften it up too.

Lots of people are also reporting success using steam to soften the putty and paint on windows.

A garment steamer or wallpaper steamer, while not the ideal, may be worth trying.

Check out this website also for video on window rehab.

Good Luck.


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Post by lrkrgrrl »

If the putty is really hard, it is better to do the whole job. When it gets to a certain point, it loses its ability to flex, and you start getting pressure cracks. I look at it this way, glazing putty is an "expendable," it's not supposed to last for ever.

Mr. X patched the putty on the windows on the ex house instead of replacing it, and we had a fair amount of trouble with pressure cracks: if the glass didn't break, then the old putty kept cracking, since it was at the end of its useful life anyway.

One of John Leeke's tips at the window workshops we attended this spring is to use wiggling motions rather than scraping and hacking. Work along the plane of the glass surface, not down against it.

Last year Himself insisted on taking on this project, hated it and ended up taking the sashes to the glass place. I've got four windows to do this summer, I'll be starting after vacation (whoo-hoo! next week...only bad thing is I really want to stay home and work on my windows. :roll: I must be nuts...)

Oh, and after Mr. Leeke's window workshops, Himself has been converted. He no longer thinks I'm totally insane for wanting to save the windows.
"Oh, Time, Strength, Cash, and Patience!"
(H. Melville, Moby Dick, Ch. 32)

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Post by Handy-J »

I had to re-glaze all the windows (about 20 - 4 pane windows) on a house I was working on a few years ago...and am in the process of re-glazing a couple dozen windows on a house I'm currently working on.

I tried the drill tool once but it seemed to break a lot of windows and left too much glaze on the frame that still needed to be cleaned off.

I have found the best way to get the old glaze off is to use a matt knife and cut down along the window frame and then chip it off the glass using a flat blade.

Don't forget to prime the frame under where the new glaze will go (they recommend an oil based primer but I've had good luck with regular water based primer.

As for the sure to get the Glaziers Tool (Home center for $5)!!!!
I did another house about 5 years ago working for a house flipper. He did a few windows and then I did the rest. When I was done he said to me, "How come when you do it they look so neat and when I do it they look so bad?" I asked him, "Did you use 'the tool'?" He replied, "There's a tool?" :roll:
A good friend will come and bail you out of jail...but, a true friend will be sitting next to you saying, "Damn...that was fun!"

My home repair Blog:

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Post by dfiler »

You could also try an infra-red heat source. This is what i'm planning on trying first. Supposedly, the infra-red heat doesn't heat glass as much as the convection heat from a heat gun. Since I haven't started yet, I can't comment on how it works in practice. The theory seems sound though. Infra-red frequencies penetrate glass without heating, but impact the putty, wood, and paint, exciting their molecules, aka: heat.

Hans Allback has some good stuff about it on his website but you'll have to look because I can't seem to find it right now:

He's a proponent of restoration with original materials and I bought a bunch of his linseed oil products for restoring my windows. Apparently he eats his own window glazing at trade shows. It is made from limestone dust and linseed oil. The advantage of this is you can glaze and paint immediately without waiting for the glazing to dry.

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Post by S »

I second the MEK suggestion. I also would replace all of the old putty even though it is a pain. I learned the hard way that replacing only part of it leads to another redo project a few years later.

Just a nit pick: Glazing = the glass. Reglazing = replacing the glass. Replacing glazing putty or glazing compound is probably what we are talking about here ;-)

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