When the glazing compound used to protect the glass inside a window wears away, a new coating may be necessary.
Glazing compound is a product used in the installation of glazing. The process of attaching glass panes to a window, known as glazing, includes applying glass putty to create a snug seal that prevents water ingress. People often need to replace compost when a window breaks or when old compost begins to crack and flake. To install new windows, many people use prefabricated fully glazed windows available through building suppliers; in that case, they just need to snap the frame and window into place and don’t have to worry about the glazing.
Glazing compound applied to wood windows helps keep water out and reduces the risk of mold.
Historically, glazing compound was a putty product and traditional putties are still available. You can also find various rubber and caulking products designed for use on window glass. In all cases, the compound must be something unique, because it must be able to make a watertight seal between two different surfaces, the window glass and the wood, plastic, vinyl, or metal frame.
When icing compound is first applied, it may be slightly sticky and gradually peels off over a day or week, depending on the product, so it can be painted over. However, the composite will remain flexible even after skinning, which is actually a beneficial feature as it sags when the wood frames contract and expand, ensuring that the seal around the window does not break. This prevents water ingress and reduces the risk of mold and eventual rot around the window frame.
If the glazing compound begins to crack and peel, it can be removed with a putty scraper or similar tool so that a new layer of compound can be applied. The stubborn compound can be heated with a tool such as a hair dryer to soften it if it doesn’t break down easily. When replacing broken windows, it is important to remove the glass, glazing points and glazing compound, sanding the frame to smooth the wood so it can be sealed with a new coat of primer before replacing the window.
Once the frame has been prepared, a thin coat of compound can be applied before gently pressing the glass into place, taking care to confirm that the compound is evenly distributed. Then the glazing points, the small metal clips used to hold the glass in place, can be attached to the frame and another coat of compound applied to seal the glass and glazing points in place. Some people do it by hand, wearing a glove to protect their fingers from sharp edges and keep dirt to a minimum, while others use a putty knife to apply it. The glazing compound should then be allowed to cure before the window frame is painted.