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slateberry

re-bed window panes in new glazing putty or...

slateberry
12 years ago

So I've been poking around about old window maintenance and restoration and read Terry Meany's book Working Windows. But I want to refine my plan of attack. For example, many sources recommend bedding the window glass in a thin, 1/8" or so bead of glazing compound (after scraping out the old bedding and prepping the wooden frame with scraping, maybe sanding, and an oil based primer).

I would like to do the rebedding step once in my life and be done with it. Reglazing I don't mind doing again, but this business of prying out all the glaziers points and trying to get the glass out without breaking it, prepping the frame, etc, I only want to do once. So, we're looking for 40-50 year performance or more. Now, I definitely plan to reglaze the windows with traditional glazing compound, but for this bedding step, I'd like to consider other alternatives. what about silicone caulk? or glazing tape? I just think the silicone would be easier and faster to apply, the glass would be less likely to break when I press it into place (because the silicone is more flexible and giving than glazing compound, which is rather stiff), and would seal much longer than the glazing compound, which eventually dries out, cracks, and powders. Am I off in my assumptions? I just want to get the best, long term results without any gotchas.

Thanks!

Comments (12)

  • brickeyee
    12 years ago

    The long life of the glazing compound is exactly why removing the old bedding is such a PITA.

    Unless the outer glazing fails, the inner bedding rarely needs any attention.

    You really only need to worry about the bedding bead if water has gotten past the outer glazing.

    Use DAP33 glazing.
    It is still the best stuff on the market.

  • liriodendron
    12 years ago

    I like Sarco putty products.

    Are you familiar with the John Leeke's website and the Old House Web? Both have active groups of people overhauling their old windows, and tons of useful info.

    Here's the urls: www.oldhouseweb.com (I usually go to the pre-1900 board; even if your house is younger than that you might still look at the pre-1900 one for additional window info.)

    www.historichomeworks.com (John Leeke's site look for the window board and brew yourself some coffee and settle in for a long read. He has tons of excellent info on saving and working on window frames.)

    As for bedding the glass: applying that little bead is the least onerous part of the job, so I would definitely use whatever you're using for putty. I haven't had a situation yet where I thought the bedding was satisfactory enough to leave untouched when I was reglazing. My windows are all 125 or more years old, so maybe they're in wrose shape than yours. I just always plan on taking out the glass, cleaning out the bedding, etc.
    Windows take a considerable amount of time so approaching them as long-term, almost once in a lifetime, projects makes sense. That's how I'm progressing through our house and barn sashes - nearly a 100 of them in all.

    L.

  • slateberry
    Original Author
    12 years ago

    Yeah, mine are 120 years old and I'm wondering if they'e _ever_ been rebedded before. Sadly Brick, looking at some discoloration to the wood, I'm betting there is glazing failure.

    John Leeke! Thanks--I've been googling John Locke window restoration Maine and getting a lot of philosophy and no window info, hee hee.

    Yeah, this is a long term project. I hope to do two windows soup to nuts this summer, and then two to three more every year. I have something like 35 windows to do, so I'll be a grandmother when I finish (just in time!).

    Oh, and my kids like to play baseball in the yard. yikes!

  • brickeyee
    12 years ago

    If you have storm windows you can work in the window sashes just about year round.

  • sombreuil_mongrel
    12 years ago

    Most times original windows had no factory bedding putty at all, but did have primer. Bed only with putty if your windows have thin early muntins, because breaking a tough caulk or silicone bond can be enough to destroy old muntins. This is one place to regard the future restorer.
    Casey

  • slateberry
    Original Author
    12 years ago

    Here is a picture of one of them for context:

    1887 window. Actually this is the one an intruder came through a couple of years ago. They grabbed an ipod and left in disgust. Hopefully they put the word out that we have lame possessions (bwahaha, they didn't know the value of our legos and extensive unit block collection!)

    The muntins are 13/16" wide. Looking carefully at where the glass meets the wood on the interior side, at first I thought they were not bedded:

    but in this picture, also taken from the interior, you can see a thin layer of something between the wood and the glass, kind of gunky chunky and sticking out in one place where I'm pointing with the deadly lego:

    so I guess they were originally bedded. I don't know if 13/16" would be considered thin for muntins, but I do want to regard a future restorer. So I guess I'm back to putty. I'd consider 100% silicone; the obstinate child in me wants to believe it could be scraped away from the muntin in 50 years without damage, but if any got out of where I wanted it to be, the non-paintable aspect of it would be an ugly bummer.

    Is there any chance, based on photos/vintage of the windows, that I could skip the points/glass/old bedding removal step, and just leave the glass in place and reglaze? I'm a perfectionist, but as I'm getting older, I'm becoming more of a pragmatist.

    I wish gardenweb had a survey feature. It would be fun to see what percentage of window restorers went all the way down to the muntins and rails, and what percentage scraped out the glazing, put in new, and went and had a beer on the porch.

  • sombreuil_mongrel
    12 years ago

    By thin muntins I meant the Federal period 5/8" type. They are delicate when brand new.
    Casey

  • columbusguy1
    12 years ago

    Slateberry, while your trim is different from mine, the color of the finish is the same as mine--from a broken window stop I am presuming the wood of my 1908 house to be red oak--would that be right?

    When I put stained glass in some diamond-shaped lights in my parlor, I found no bedding, and the original was not painted--it just had points and the outer putty. When I put in the new glass, I just did the same thing since that window is protected by my front porch.

    I had to replace cracked glass in two other windows, one in the attic, and the other in the kitchen, and neither had paint or bedding. Neither did the storm on my sidelight, which is the original.

    I am starting this year to redo my storms (replacing aluminum crap with wood), and will reglaze my sashes as well--but I WILL prime before putting back the old glass--without bedding since there will be storms. I read somewhere that the bedding is mainly to prevent rattling from road traffic, and for water protection if there are no storms.

    Here's a question: my kitchen window was rabbetted around three sides, but not the top--there was a slot there which the glass slid into before you put it in the rest of the way. How weird is that? Anyone else have that?

  • sombreuil_mongrel
    12 years ago

    IMO the most valuable thing bedding does, aside from the non-rattling, is preventing condensation from dripping down into the glass rabbet. The seal is really important, because water entering there pops the putty loose quickly.
    Casey

  • miragesmack
    12 years ago

    "Here's a question: my kitchen window was rabbetted around three sides, but not the top--there was a slot there which the glass slid into before you put it in the rest of the way. How weird is that? Anyone else have that?"

    Hi! My sister's kitchen door is done like that, although it's been modified in so many ways, we're not sure what to do with it now. Intruders broke the non original wood out and she wants to put glass back in, but it's a conundrum on how we accomplish that without routing that fourth edge to match the others.

  • sombreuil_mongrel
    12 years ago

    The three rabbets and a slot is the way bottom sash are milled. It obviates the need to putty the hard-to-reach area, while giving a cleaner look from outside, and maximizing the glass area and making the check rails more skinny. I always fill that slot with soft putty and carefully slip the edge of glass into it, Without putty it's a draft source.
    Casey

  • columbusguy1
    12 years ago

    Thanks Casey! I didn't know that...I thought I should just putty that edge like the others, but didn't since it would be visible from the inside. I'll have to do that when I get to the new storms!

    Mirage, I'd just make the glass a tiny bit longer and the proper width and insert it into the door. My back door has its original glass, as does my front, will have to check whether they have slots or not, though the front's bevelled glass has egg and dart molding on all four sides.