Methods of window repair depend on the window style. Storm windows differ from traditional windows. If a storm window glass pane breaks the first task is to carefully remove any glass left in the metal window frame. Wearing a good pair of sturdy gloves is a good idea. Before you tear the frame apart you also want to measure the inside dimension of the frame. This measurement will be the size of the new pane of glass you order from the glass shop. The shop will also want to know the width of the glass. You can retrieve that dimension by measuring one of the larger pieces of broken glass or measuring the width of the slot or trough in the metal frame.
While you are waiting for the glass to be cut you can prepare the metal frame for the new glass. Remove all the small pieces of broken glass from the frame’s inner slot. Remove, at the same time, the rubber gasket that runs around the entire inner slot of the metal frame. If the gasket is still in good shape, save it for reuse. If it is worn, ask the glass shop for a new one. Take a sample of the gasket in when you pick up the glass pane. When the glass shop people see the old gasket they have a better chance of making certain you get the right size gasket.
Now, to get the pane of glass into the frame you will have to dismantle the metal frame. If at all possible remove only one side of the frame. That way you only have to slide the glass into the frame. You slide the glass, of course, into the slot on the inner side of the metal frame. If the frame falls apart as you try to remove one side don’t panic. It will just take a little more patience and dexterity to put the frame around the edges of the glass pane. Do your best to line up the four corners so they fit snugly with no protruding corners.
Next is the delicate part. With the glass pane in the metal frame you have to wedge the rubber gasket in the inner slot of the frame between the glass pane and one side of the metal frame slot. Be very careful. Too much pressure can break the glass. Be patient and don’t force it. One helpful tip is to tape the four sides of the frame together into a rectangle around the glass pane. This will temporarily hold the glass in the pane and the frame together until you can place the rubber gasket. The gasket, which runs continually and entirely around the metal frame, is in essence what holds the glass in place and the frame together.
One final trick. Sometime the corners of the metal frame are nearly impossible to fit snugly together. They wear down and bend over the years. If this is the case, a little piece of duct tape or some hot glue can hold the corners together.
The traditional window frame is usually made out of wood. A double hung window means the window is divided in two and the bottom window can slide up or down to open or close for ventilation. These are the windows found in most homes. Fixing a broken glass pane in this type of window is not that difficult.
First, remove the broken glass still remaining in the window frame. You might want to wear some sturdy gloves for protection. Once that is done you want to remove the wood molding around the inner side of the windows frame. This is a small, narrow piece of wood that encircles the window, helping hold the glass pane in place. Using a small putty knife is usually the best tool here. Slip the knife under the moulding and gently pry up. The molding is held in place by very small brad nails. You are trying to pull them out of the wood. There are four molding pieces, one for each side. While removing this molding be careful of any glass that may still lurk behind the molding. Also try to save as much of this molding in one piece as possible. Reusing the molding means you won’t have to paint new molding to match the surrounding colors. Nor will you have to cut new molding. Given the molding’s small size and the skill needed to make neat mitered corners, cutting new moldings may not be so easy.
Once the molding is out there is usually numerous small metal triangles, called darts, holding the glass in place. As always be careful removing these darts as there may be some glass left behind the darts. Pull these darts out. A good pair of needle nosed pliers works well here.
Finally, the small notch that runs around the inside of the window, in which the glass sits, will contain window putty. The putty may be rather dry. This putty needs to be removed. Every bit of the putty needs to be removed to the point the wood is bare. By the time the putty is removed there should be a clean 90 degree, angled shelf for the new window pane of glass.
When the new glass pane arrives at your house set it aside for a minute. First you need to put window putty in the small inner notch that runs around the window frame. The glass pane will sit in this notch and putty. The window putty in the notch will help hold the glass pane in place as well as help waterproof the window. Nowadays there are a number of materials to use for this. There is the traditional window glazing. This is rolled into long strips locking like spaghetti noodles and laid in the notch. Or it can be applied with a small putty knife. There are also pre-rolled strips. Finally, you can buy the window glazing in a tube of caulk and apply it by squeezing the tube or putting the tube in a caulk gun.
Once the putty is laid, place the window in the frame and gently squiggle the glass pane into the putty so it seats itself well. Now take the darts you took out of the window a few minutes ago, or the ones you bought at the glass shop, and gently push them (do not hammer them!) into the putty alongside the glass pane. This is another precaution to hold the glass pane in place. The last step is to replace the wood molding. If the molding you took off is in good shape you can re-use it. If not you will have to get some new molding that matches in size and shape, cut accordingly and place along the window on the notch. Here is your last delicate work. Use very small brad nails to hold the molding in place. Obviously the brads should go through the molding into the wood frame of the window, not into the glass.
Take your small putty knife and scrape off any excess putty that has squeezed out during this process. If you had to use new molding you will need to put a coat of primer on the molding and then a finish coat of paint that matches the color of the rest of the window.