Restoring Antique Wooden Window Sashes – Repair, Reglaze, Revive

Article 47: Restoring Antique Wooden Window Sashes – Repair, Reglaze, Revive

By: A Woodworker Who Sees History in Every Pane

Wooden sashes can last over a century with proper care. Restoration includes replacing glass, scraping paint, and reglazing with traditional putty.

Materials

• Glazing putty (oil-based or DAP 33)

• Glazing points

• Replacement glass (if cracked)

• Shellac or oil primer

• Exterior paint

Tools Needed

• Heat gun or infrared stripper

• Glazier’s knife

• Sandpaper (120, 220)

• Small hammer

• Chisel

• Utility knife

Steps

1. Remove Old Glass Carefully

   • Use heat gun to soften putty. Pry out glazing points and lift the glass.

2. Clean Rabbet

   • Scrape all old putty and paint. Sand lightly.

3. Replace Glass

   • Cut to size and dry fit. Apply a thin bed of putty under the glass.

4. Add Glazing Points

   • Insert one every 6–8 inches. Press flush to glass.

5. Apply Bevelled Putty Line

   • Smooth with glazier’s knife at a 45° angle. Allow to cure 5–10 days before painting.

Sketch – Window Sash Cross Section

Cross Section:
   __________
  |   Glass  |
  |__________| ← Set in putty
  |  Rabbet  |
  |__________|
     Frame