Things You'll Need
Aluminum windows that are installed in older homes may have glazing that will harden or crack over time and need to be replaced. Glazing is a technique that is used to secure and seal glass panes to the framing. Before you can glaze an aluminum window, you will need to clean and prepare the frame for the new glaze. This will require you to first remove the old glaze from the window.
Remove the window pane out from the windows by pulling it out of the aluminum tracks. Set the window pane on a table, bench or a pair of sawhorses.
Remove the old and loose glazing compound from around the glass with the putty knife. Apply heat with the heat gun to soften the remaining compound. Scrape away the remainder of the glazing from the glass on the window pane.
Remove the glass from the window and clean any debris or old caulking from the frame with the putty knife.
Apply a bead of caulk around the inside of the frame and then set the glass back in place. Press the glazing points into the frame every 8 inches.
Allow any excess caulking that comes through to dry or harden and then cut if off with the utility knife.
Open the container of glazing putty and fill in the edges where the frame and glass meet with the putty knife.
Pour a small amount of mineral spirits into a container. Dip the putty knife in the mineral spirits and then run it over the glazing putty. Re-dip the knife and run it over the glazing putty until it is smooth.
Remove the excess ridge of glazing by pulling it away from the frame and then scraping it off of the glass.
The glazing putty will completely harden within two to three days.
Do not leave any gaps or hollow spots when applying the glazing putty to the window.