How to Appy Window Glazing

Remove the old glazing. Concentrate on the glazing that is old, flaking and loose. Glazing that still forms a secure bond to the window does not need to be removed. Use a putty knife and scraper to knock off the old putty. Be careful not to damage the points, little metal triangles that hold the glass in place. If you do want to remove all the old glazing, then it needs to be heated up before it can be removed. Use a blow torch or heat gun set at a low level. Heat the old glazing until it becomes soft and then use the putty knife or scraper to remove it from the window frame.

Brush off all dirt and debris. Once all the old loose glazing has been removed, use a wipe to clean the windows. The new putty will not adhere to dust or other debris.

Prime the bare wood around the window before applying new glazing putty. Primer seals the wood and provides a better surface for the putty to adhere to. Glazing putty will eventually pull away from bare wood. Apply the primer with a trim brush and let it dry for 24 hours. Let any primer that gets on the glass dry and then scrape it off with a razor blade. Wiping wet primer will smear the glass and make cleanup more difficult.

Warm the glazing putty up in your hands. Scoop out a bit of glazing putty from the container with the putty knife. Roll the putty around in your hands making a ball shape. This makes the putty more pliable and easier to work with.

Apply the putty to the window with the putty knife. This is done in two stages. First, use the putty knife to apply the glazing putty to the window frame. Put putty on the end of the putty knife, and press it into place forming a bond with the glass and the window. Start on the left edge and work your way to the right, filling in the gaps that need new putty. Once one section of window frame has been filled in, use the putty knife to smooth the glazing and make it even. Press it down so that it is even with the outer edge of the window frame and with the inner edge that meets the glass. Then slowly move the putty knife towards the right pressing it slightly down towards the window. This helps the glazing putty make a tight fit, makes a smooth line and removes excess putty from the glass. You should not be able to see the putty from the other side of the window.

Lightly go over the new glazing putty with a damp small paint brush. This step is only necessary for areas where the new putty is not even or smooth. If some areas are still a little rough and uneven, dip a small paint brush in clean water and use the brush again to lightly smooth out the line.