To reglaze your old windows, remove the old glazing, clean the frame, prime the wood, apply new glazing putty, install or reset the glass pane, and smooth and cure the putty before painting for a sealed, restored finish. For more in-depth information on window glazing, be sure to check out our triple glazing page.
Step-by-Step Guide to Reglaze Your Old Windows:
1. Remove the Old Glazing
Start by carefully scraping away the old, cracked glazing putty using a putty knife or a chisel. If it’s hardened, use a heat gun gently to soften it. Be cautious around the glass to avoid breakage.
2. Take Out the Glass Pane (if necessary)
If the glass is loose or you’re replacing it, wear gloves and remove the pane slowly. Note the size for replacement if it’s damaged.
3. Clean the Frame and Rabbets
Once the old putty is off, clean the wooden window frame thoroughly. Remove any leftover glazing, paint chips, or dirt so the new putty adheres properly.
4. Prime Bare Wood
If you expose bare wood during cleaning, apply an oil-based wood primer. This helps prevent the wood from absorbing the putty’s oils and ensures better bonding.
5. Install or Reinsert the Glass Pane
Place the glass back into the frame and press it gently into position. Use glazier’s points (usually every 4–6 inches) to secure the glass in place.
6. Apply New Glazing Putty
Roll the putty into thin strips and press it into the edge between the glass and frame. Use a putty knife at a 45-degree angle to smooth it out evenly. The ideal glazing angle should shed water away from the glass.
7. Let the Putty Cure
Allow the putty to cure properly it usually takes 7–14 days depending on humidity and product type. The surface should be firm before painting.
8. Paint Over the Glazing
Once cured, paint the putty with exterior-grade paint to seal it and protect it from weather. Overlap slightly onto the glass to prevent water from seeping in.
How to Reglaze a Window Without Removing It?
To reglaze a window without removing it, scrape out the old putty, clean the area, apply primer if needed, press in new glazing compound, and smooth and seal the putty all while keeping the glass pane in place.
Step-by-Step Guide to Reglaze a Window Without Removing It:
Scrape Out the Old Glazing Putty
Using a putty knife or a painter’s multi-tool, gently remove the cracked or loose glazing putty from around the glass. Be careful not to damage the glass or wooden sash. A heat gun can help soften stubborn putty.
Leave the Glass in Place
Do not remove the window glass. If the glass is secure and not broken, you can reglaze directly with it still in the frame.
Clean the Surface
Remove dust, flakes, and old paint from the window sash and glass edges. This ensures the new putty sticks well and seals properly.
Prime Bare Wood (if exposed)
If scraping exposes bare wood, apply a light coat of oil-based primer. Let it dry before proceeding. This prevents the wood from drawing oil out of the new putty.
Apply New Glazing Compound
Knead a small amount of glazing putty until it’s soft and pliable. Press it firmly into the groove (called the glazing rabbet) between the glass and sash. A glazier’s knife works best for shaping.
Tool the Putty to a Smooth Finish
Hold the putty knife at a 45° angle and smooth the putty into a neat, beveled edge. It should slightly overlap the edge of the glass to create a weather-tight seal.
Let the Putty Cure
Allow the putty to cure for at least 7 days, or as recommended by the manufacturer. The surface should be firm before painting.
Paint to Seal the Putty
Once cured, paint over the putty with exterior paint to protect it from moisture. Extend the paint line slightly onto the glass for a complete seal.