How to Remove Old Putty from Windows

Lead Image
  • 1-3 hours
  • Beginner
  • 100-120
What You'll Need
Eye goggles
Dust mask
Putty knife
Hair dryer
Heat gun
Drywall knife
Putty chaser
Oven cleaner

Removing putty from windows can be challenging. Often the putty has hardened or has been painted over. There are steps you can take to remove the putty. These are listed below from the simplest to the most aggressive methods.

Step 1 - Protect Yourself

You can easily cut yourself when working around glass. Wear leather gloves and eye protection to avoid any injuries. Some old putty contains lead so if you are working on an older window use a dust mask.

Step 2 - Prepare the Window

Take the window from the frame if you can. If there is any loose broken or cracked glass remove as much as you can to avoid cutting yourself while removing the putty.

Step 3 - Use a Putty Knife

Use a putty knife to try to lift the edges of the putty. Be careful when putting the knife between the glass and the putty. If you exert too much pressure you could damage or break the glass pane. You can place the knife horizontally between the putty and the wood and push gently but firmly. If you push too hard the edge of the blade may break the glass.

Step 4 - Heat up the Putty

Get out your hair dryer and turn it to the highest setting. Apply the hot air to the hardened putty. Going back and forth over a small section of the putty will usually soften the putty making it easier to remove with a putty knife. Once that section is removed go on to the next section.

Step 5 - Use a Heat Gun

To apply even more heat you can use a heat gun to soften the putty. Put a long metal drywall knife between the putty and the glass to protect the glass from the heat. Apply heat from the heat gun and using a heat resistant chisel chip away as much putty as you can. Work on a section just a few inches long at one time. If the removal is successful then move onto the next section and repeat the steps.

Step 6 - Steam

One method used by window restorers is to use a steamer. This special steamer applies steam to a 6-inch section of the putty at a time. It is especially useful for putty that has been painted over numerous times as it softens the paint as well.

Step 7 - Use a Putty Chaser

If you have a drill you can get a putty chaser which is a bit that attaches to your drill and uses the power of your drill to cut away the putty. You must be careful with this method not to get the drill too near the glass.

Step 8 - Use Oven Cleaner

This product should be used only in a well-ventilated room. Don’t leave it on too long as it might damage the surface of the wood.

These steps will help you to remove putty more easily so that you can restore your windows. Choose the one that works best for you.