How to Restore Old Wood Windows

We consider it lucky to have found this house with almost all original wood windows. This isn’t typically the mainstream opinion, so I’ll start with why we love this feature and had absolutely no intention of replacing the windows with replacement vinyl windows. Then I’ll show you step by step how I’ve learned to restore each window as someone who has never done this before!

Why not replace?

Vinyl window replacement ads have gotten far too much air time and traction over the years. So here’s a case for why you SHOULD NOT replace beautiful original wood windows in an old house.

Here is the before and after of the first window that I pulled out to restore with new glazing and paint. This window and most of the other windows in the house are nearly 200 years old!

Did you know that a properly glazed window will last about 30 years?! A standard replacement vinyl window lasts 20-40 years and costs at least $200 per window. A bucket of glaze and two cans a paint is about $150 and will be enough to do all these windows. The rest is just time and care. You do the math 😉

Beyond the fiscal aspect, old houses with vinyl replacement windows lose a huge part of their old house identity. Those original windows were built by true craftsman and it’s easy to see the detail that they put into each one. Also, wavy glass!! 😍

I know what you’re thinking… but it won’t be energy efficient. This is what vinyl replacement salesman want you to think! A well restored wood window will not lose much more heat than vinyl. With an added storm window and when possible, insulation added around the window frame (under the trim), there’s almost no difference at all. By the way, vinyl replacements lose their efficiency over time too, but they can’t be restored which just means more money and more waste.

I’ll be sharing what I’ve learned while restoring our old windows, but I’m definitely not a master. If you want to learn how to reglaze windows from a master, I highly suggest watching videos from Steve Quillian at Wood Window Makeover!

Cleaning Methods

Cleaning up an old window sash is the first step and can be one of the most time consuming parts of restoring and reglazing an old window. So I’ve tried two different methods and here’s a breakdown of the pros and cons of each.

Steam Box vs. infrared Heat

Steam box method

Pros

It softens the glazing well enough that it’s fairly easy to remove the glazing. Different glazing responds a little differently and may need more time steaming.

Cons

This works better if the paint is already stripped from the sash so that the steam gets between the glaze and wood.

It’s has to steam for quite a bit of time to soften enough. This one steamed for about an hour and a half.

The wood softens as well, so it’s easier to damage it while trying to get the glazing out.

Once all the glazing is out, the sash needs time to dry out. This may not be a big deal if I were doing multiple windows at once and alternating work on each, but since I’m only doing one at a time, that means I can’t make any more progress until it’s dry.

Infrared Heat

Pros

The glazing softens and comes out nicely and leaves the wood fairly clean in most cases.

Once the sash is clean, I’m able to prime it immediately and can start reglazing the glass when the primer is dry.

Infrared heat doesn’t vaporized lead paint, which basically all these windows probably have. Yay!

Cons

It takes more active time going over it all with heat where I can be doing other things while a sash is in the steam box.

I’m using the Eco-strip Cobra Infrared Speedheater (If you purchase something after clicking on this link, I’ll probably earn a small commission), which is fairly expensive. There are other options out there, but I have not tried them and can’t speak to how well they work. I chose the cobra as I knew I would be stripping paint off lots of stuff for this house and it’s been incredibly helpful saving time.

What do I prefer?

Both methods work fairly well, but I prefer the infrared heat method because I’m already stripping off the paint from the sash and then I’m able to move on to priming it right after.

There you have it, let me know what questions you have!

Removing the glass

Getting the glass out without breaking it can be a challenge. Every sash that I’ve restored needed at least one pane replaced either because it was already broken or I broke one while removing it. I always have extra glass around just in case.

Here’s what I’ve learned:

Make sure all the glazing points are out! There are different kinds, some are bigger and easy to see and some are very small, even just a small shard of metal. Sometimes they blend in and are easy to miss. I run my putty knife along the edge to make sure they are all out.

Sometimes the glass is really loose and comes out easily and sometimes it doesn’t. When there’s resistance, I always try to figure out what’s keeping it from coming out. It might be a small amount of glazing left on the mutin or tight on one side.

Once one side is loose, I very carefully ease it out of the sash.

Check out the waves in this glass as it moves under the light!! 😍

Stripping Paint

Paint stripping

The glazing on this sash was either already missing or came out with little effort. normally I would strip the paint before removing the glaze. Here’s how I strip the paint!

Product links:

Paint scraper (If you purchase something after clicking on this link, I’ll probably earn a small commission)

Vacuum scraper attachment (If you purchase something after clicking on this link, I’ll probably earn a small commission)

Ecostrip Cobra Speedheater (If you purchase something after clicking on this link, I’ll probably earn a small commission)

Priming the sash

Make sure the sash is clean and free of dust. Use an exterior oil based primer. Oil based paint is hard to find right now, so I’ve been using an alkyld paint requiring mineral spirits to clean up.

Don’t paint the sides! Any part of the window that will move in the wood frame should not be painted.

Product:

Benjamin Moore- Fresh Start Exterior wood Primer

Cutting Glass

I cut the glass to fit each individual pane since none of them are an exact size or angle.

Dip the glass cutter wheel in mineral spirits.

Put a lot of pressure evenly as you score the glass.

Gently drop the glass on the edge of your work surface to break it on the score line.

Product links:

Glass cutter (If you purchase something after clicking on this link, we’ll probably earn a small commission)

Razor blade scraper set (If you purchase something after clicking on this link, we’ll probably earn a small commission)

Glazing the window

Always bed the rabbet with glaze! This ensures an air tight seal.

I always dry fit the glass panes to make sure they fit will in the sash. They should not be super tight against the wood but should sit on top of the rabbet.

Gently put even pressure to set the glass into the glazing bed. The glaze will squeeze out on the other side.

Once it’s set, the glazing should not have any noticeable gaps underneath and should create some suction making it difficult to take out.

Product link:

Sarco Type M putty (If you purchase something after clicking on this link, we’ll probably earn a small commission)

Setting Glazing Points

Most of the windows I’ve restored have narrow rabbets. So I trim the glazing points with tin snips so they don’t stick out to far but still hold the glass in place.

Once the points are in place, flip it over and cut away the excess glaze on the other side.

Product link:

Glazing points (If you purchase something after clicking on this link, we’ll probably earn a small commission)

Cutting the Glaze

I use a putty knife with a beveled edge to cut the glaze. This is the only task I use it for so that the edge doesn’t get damaged.

Before I use it I dip it in some mineral spirits to make sure it’s clean.

Hold the knife as parallel to the window as possible to keep the glaze smooth.

Set the angle and keep it tight against the muntin as you pull it across.

Clean up the corners and let it set for 3 days!

Product link:

Putty knife (If you purchase something after clicking on this link, we’ll probably earn a small commission)

Glazing efficiently

When there’s lots of windows to restore, doing it efficiently is important! Here’s some tips on how to glaze faster.

Instead of doing one pane at a time, I complete each step for the entire sash.

To reduce the number of times I need to readjust my grip or position, I work on all the rabbets facing the same direction before moving to the next. This means I’m only readjusting or repositioning 4 times for the entire sash.

Once the sash is glazed, I use whiting powder (calcium carbonate) and an old stuff paint brush to clean up the finger prints and markers on the glass. This saves lots of time later cleaning the glass. It also seems to help the glaze set up faster.

Painting the sash

I use a 1 inch angled brush and a quality exterior paint.

A bead of paint should go onto the glass to protect the glaze. To do this without having a lot of clean up, I use the edge of the bristles with very little paint to create a line that just touches the glass.

I do not recommend using the film to cover the glass that pulls away after painting. This will break the seal created by the edge of the paint and allow moisture to get to the glazing.

one more coat of paint and these will be ready to be reinstalled!

Products links:

Whiting powder

Benjamin Moore- Regal exterior paint

To see the finished windows in the parlor bedroom, check out the Parlor Bedroom Transformation