Window | Putty Repair

Usually, only the exterior of the window has glazing putty. The interior is typically held by wood stops (molding). If the interior is sealed with putty, follow the same steps, but you generally do not need to be as aggressive with the heat gun, as interior putty is often softer.

The good news? Repairing window putty is one of the most satisfying (and budget-friendly) DIY projects you can tackle. For the price of a few tubes of caulk, you can stop drafts, prevent rot, and save hundreds on replacement windows. window putty repair

There’s something charming about old wooden windows. But let’s be honest—that charm fades fast when you notice chunks of hard, crumbly white stuff falling out of the frames. That “white stuff” is (or glazing compound), and when it fails, your windows fail. Usually, only the exterior of the window has glazing putty

Do not just chip away wildly—you can break the glass. The good news

: Essential for prepping the wood or metal frame before applying new putty.

asbestos to increase fire resistance and strength. If the putty is original to a building from the mid-20th century or earlier, it should be tested before removal. 3. Repair Procedure A professional-grade repair involves several distinct phases to ensure a lifespan of 10–15 years. A. Preparation & Removal Remove Old Putty: Gently use a stiff putty knife to scrape away loose or cracked material. For metal frames, ensure all rust is removed and spot-primed with an anti-corrosive primer. Seal the Substrate: Bare wood must be painted with a universal undercoat or oil-based primer. This prevents the wood from absorbing the oils in the new putty, which would cause it to crack prematurely. B. Application Kneading: Putty must be kneaded for several minutes until it reaches a doughy, non-sticky consistency. Pressing: Press the putty firmly into the joint using your thumb or a knife to ensure a solid bond with both the glass and the frame. Tooling: Use a putty knife to compress the material and create a smooth, angled "fillet." The top edge should be level with the interior putty to remain invisible from inside the room. C. Curing & Finishing Drying Time: Traditional linseed oil putty typically requires