How to Reglaze a Window

  • From time to time—more or less every 15 years—you’ll notice that your old window needs you to take action. For example, when it’s broken, or the glazing simply got worn out, windows need to have their old putty removed.
  • In the article below, we’re tackling the process of window replacing, which at some point will be necessary for every old house.
  • Follow our tips to learn how to remove the old and do the job of returning the glass in place. Keep reading to discover it all!

Meanings of “glazing”

The word “glaze” or “glazing” refers to various actions. One of them is pretty cute—you dip doughnuts into the glaze before serving them. 

But we will focus on the structural “glazing.” 

Window reglazing is window pane replacement. 

It’s a cost-effective solution compared to a window replacement.

The word “glazing” also has different meanings.

In painting, glazing is a standard technique whereby a person applies a thin layer of paint on top of the dominant color, resulting in rich, iridescent colors. The glaze technique requires special semi-transparent paints. 

Many Renaissance artists commonly utilized this technique—glazing was a way of mixing paints.

Glazing, as a noun, is the name of the hardened putty (glazing putty) that creates a weather tight seal on the exterior of the window—between the wood and the glass. 

This part can fall off with time or become badly cracked. 

A window with such a flaw becomes vulnerable to the effects of water and rot. 

When to reglaze a house?

In this article, we’re focussing on window reglazing.

Replacing glass is helpful in case of:

  1. a broken pane, or 
  2. deterioration of glass over time;

This solution is affordable (compared to replacing the windows), and you still get the benefits:

  • energy savings, 
  • better heat gain, and 
  • less heat loss;

If you have an old house, it may be the best option for you. 

However, it’s commonly believed to be more of a temporary fix—older windows usually have problems that go beyond the glass.

Keep in mind that you don’t have to replace all the windows in your house at once. 

If only one of them needs restoration, reglaze a single glass. 

How to reglaze a window?—instructions

Now, let’s get down to business.

Reglazing a house is easy if you follow a few simple steps.

  1. Examine the situation

Check the condition of your windows by thoroughly examining their exterior.

If the glazing has a few hairline cracks here and there, keep an eye on it and occasionally check to see if things get any worse. 

If there is glazing missing, or if you can fit a knife blade in the cracks, it’s time for window glazing.

Repairing the glazing compound is a crucial part of the repair of a window in a historic building. 

Grazing holds the glass window panes in their wood frames. 

The glazing compound:

  • seals the wood, 
  • helps hold the glass to the sash, and 
  • sheds water away from the wood; 

Failed or missing glazing compound is a significant cause of energy loss in any window.

2. Remove the old glazing

To replace the window, first, you need to remove the sash, i.e., the operable part of the window (where it slides up or down). 

Remove the stops—tall, thin pieces of wood that sit on the window’s interior to each side of the opening. They are perpendicular to the sash. They’re usually attached with three screws each. 

If the stops are painted, use a razor knife to break the paint line to remove them.

Once the sash is out, it’s time to remove the lousy glazing. 

Take a razor knife or scraper and start chipping off the loose glazing.

Parts that remained until this point are stuck to the wood and glass exceptionally well. 

Continuing to use a razor knife, you risk breaking the window or damaging the wood frame, so consider using a heat gun. It will soften the glazing—it almost falls off the surface of the window by itself. 

Important: The intense heat also has other repercussions. It will most probably do some damage to the surrounding paint. As a result, you’ll also have to scrape and repaint the entire window.

Be aware of the glazing points. These are the small metal clips holding the pane of glass in place. These points are buried in the glazing (probably at the center points of the sides). You can remove these points with pliers.

3. Examine the wood frame

The old glazing putty is now removed, so you can carefully examine the wood.

Does it look like it needs any repair?

If you consider it necessary, patch the wood with a two-part wood epoxy. You can shape and sand it to match the wood.

Do you feel like priming the bare wood that you’ve just uncovered?

There is an ongoing discussion about the necessity of doing it. Decide for yourself and let us know what’s your opinion on this part of the project!

4. Replace the glass

If the problem was a broken piece of glass, you need to place a new one.

Start by measuring for the new piece—take the dimensions of the wood-to-wood opening and subtract a one-eighth inch. 

Tip: The ideal is when the glass fits but isn’t jammed in too tight. The best way is to leave a one-sixteenth inch of free space on each side. This way, the glass will fit easily but remain snug enough for the glazier’s points to hold.

Once you have cut the piece of glass, lay down a thin layer of glazing compound on the wood frame.

Then, set the glass against it, secure it in place with new glazing points, and press into the frame with a putty knife.

5. Reglaze

We’re one step from the end. 

It’s time to apply the new glazing putty.

If case you deal with only one or two small panes, you’ll be good with a half-pint container of glazing. 

Your glazing compound needs to be at room temperature. Moreover, to even out its consistency, work a golf-ball-size glob in your hands for a minute or so.

Hands can work oil based glazing compound until it gets malleable enough to be spread cleanly with a putty knife. Use only the organic raw linseed oil for the glazing putty. 

Roll it out and work the piece in along the edge of the windowpane. 

Tooling the glazing comes in two parts:

First off, press the glazing into the glass and the frame and smooth it off. Do it with a putty knife, pushing it against the wood and the glass. Remove the excess as you go. You want the inside edge of the glazing to be in line with the wood mullion on the other side of the window.

Then, take the putty knife and run it at an angle along with the glazing. Here, we’re focussing on smoothing it off and cutting the excess away (scoop it with the corner of your putty knife and push it toward the center of the window).

6. Primer and paint the glazing compound

Allow the glazing compound to cure for 24 hours. 

Then, you can prime the compound with an oil based primer—apply oil or latex paint topcoats onto your new project.

Then, we suggest you wait at least a week to paint the glazing.

Paint your window with a high-quality oil based primer. 

Lap your paint onto the glass at least one-sixteenth of an inch. Otherwise, your glazing will fail long before the time is due.

Related articles

Frequently Asked Questions

A standard window repair costs between $160 and $520. Various factors influence the price of window restoration.  
Windows that were made 15 years ago or earlier may need reglazing.
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