How to Replace Insulated Glass in an Aluminum Window with Snap-In Glazing

This step-by-step tutorial shows how to replace glazing bead and insulated glass in an aluminum window sash.

How to replace snap-in glazing bead and glass

Whether your glazing bead becomes brittle and dry from prolonged exposure to sun and inclement weather, or you’re in a situation that requires new glass, this step-by-step tutorial will demonstrate how to replace snap-in glazing bead and insulated glass in an aluminum window sash.

Necessary Tools:

WARNING: be sure to wear safety glasses and use caution while working with glass

Required tools

STEP 1
Once the sash is removed, place it on a flat surface and use a slotted screwdriver and stiff chisel putty knife to loosen the lower leg of the beading out of the groove in the sash. Repeat on each side until the old snap-in is completely removed.

Remove snap-in
Remove snap-in

STEP 2
Once your snap-in is removed, compare the style and dimensions of the original piece to determine the correct replacement for your sash.

Measure snap-in
Measure snap-in
Determine replacement snap-in
Determine replacement snap-in

STEP 3
Turn the sash over and loosen the sealant with help from a heat gun. As you use the heat gun, run a utility knife along the edge of the sash. Once the sealant is fully removed, the glass should be free to drop out of the sash.

Loosen sealant with a heat gun
Loosen sealant with a heat gun
Remove glass from the sash
Remove glass from the sash

STEP 4
If you are replacing the glass, measure the height, width, and thickness. Pass along any manufacturer information and the dimensions of your glass to your repair shop for a better idea of your replacement lead time.

Measure glass
Measure glass

STEP 5
Set the glass aside to begin working on the frame. If your window has setting blocks, mark the general location of them in the lower section of the frame. Sometimes called shims or spacers, setting blocks serve as a cushion between the glass and the frame. While they don’t need to go in the exact location, be sure to return them to the same portion of the sash frame when resetting your glass.

Mark locations of setting blocks
Mark locations of setting blocks

STEP 6
Now, use a chisel and heat gun to scrape excess sealant from the area.

Clean off remaining sealant
Clean off remaining sealant

STEP 7
Use a caulk gun to run a bead of sealant along the inner edge of the frame. We prefer to use a translucent latex-based caulk, as it’s easy to clean up mistakes. Just use a bit of soap and warm water to get rid of any excess caulk. Place the setting blocks back in the frame with a little caulk.

Apply caulk
Apply caulk
Replace setting blocks
Replace setting blocks

STEP 8
Now, carefully place the original or new glass unit back into the sash frame.

Place glass back into the frame
Place glass back into the frame

STEP 9
To install the new snap-in glazing strips, first measure and mark the needed lengths. Use Wiss snips to cut and shape the new beading. For the longer sides of the window, cut the snap-in to the needed length, then angle the shorter sides to meet them.

Measure and mark snap-in
Measure and mark snap-in
Cut snap-in
Cut snap-in

STEP 10
Set the top edge of the beading into the groove in the sash. Then, place the lower leg onto the glass, making sure it snaps into place against the glass.

Install snap-in
Install snap-in

CONTRACTOR TIPS

Since replacement glass can take weeks to fulfill, you may want to keep the glass in the frame until the new unit is ready. To avoid bringing the entire frame to a glass repair shop or hardware store, measure the length and width with a measuring tape, then use Glass Calipers to measure the thickness. Since glass calipers can give an accurate read while the glass is still installed, it will save you the trouble of removing the original glass before you’re ready to replace it with the new glass.

Use the calipers by sliding the jaw around the sash frame. For an accurate measurement, slide the adjustable jaw until the adjusting screw touches the glass.

Use glass calipers

If you’re working on several windows, speed up the repair up by using the E.Z.D Glazer in place of a utility knife in step 3. Run the de-glazer along the edges of the frame to loosen the old caulk that’s holding the glass in the frame. With proper care, this tool can withstand multiple years of use. Just replace the cutting wheel periodically.

For contractors or anyone else working on a larger scale version of this repair, consider adding a Vacuum-Powered Grip to your needed tools list for step 8. The 8” suction cup can lift up to 125 lbs., making it much more time-effective to reinstall the glass over the course of many windows.

To see our experts complete this repair, watch our video below. For the parts featured in this tutorial, or additional guidance, visit us at SWISCO.com.

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