A window replacement might be the Rolls Royce of home improvements, but it has a price tag to match. Learning how to glaze window surfaces already in existence greatly improves the look of the home and warmth inside. What window glazing tips do you need to know?
Uninstall the window first! Remember that you are most likely dealing with aging wood and single pane glass. One false move and you might find yourself replacing a glass pane while you’re at it.
Lay it flat on a solid surface. Work with a utility table that is big enough to hold the window. It makes the labor easier on the back. Glazing windows requires a bit of elbow grease.
It looks worse before it looks better. Removing the old glazing compound is a must. Doing so is not a pretty sight and will most likely introduce you to prior homeowners’ ‘fixes’ that make it look as though the window is held together by little more than glaze and putty. Keep on scraping away the old, dry stuff with a putty knife. It will continue to look bad until you put it all back together.
Heat is your friend – and enemy. To soften up the old window glazing compound a heat source is a must. Keep it trained too long on one spot on the glass, and the pane might crack.
All window glazing compound is not created equal. There are actually hot debates raging about which product is superior when glazing windows, but preservationist John Leeke goes on record that “each has its place in good window work.” Linseed oil-based compounds (like MultiGlaze), modified oil-based compounds (DAP 33) and acrylics (Aqua Glaze) all have advantages and disadvantages.
While acrylics can be painted right away, the long drying time of oil-based products lets the DIYer get the coverage just right and the result is much smoother.
Remember the one-two punch of draft reduction. Apply clear latex putty to the wood frame and gently push the window panes in place. Let this setup dry and cut off the overage with a sharp utility knife. Then go ahead and apply the putty. The resulting seal is a bit of insurance that keeps out cold air and moisture even if the putty fails over the course of the years.
For my California readers: Those little coarse grains of sand … they’re termite poop. Termites love wood and window frames are no exception. When removing the old glazing, and getting down to the bare wood, it is not uncommon to get face to face with an old infestation or a currently thriving colony. Be prepared to play exterminator and replace wood that has been damaged by termite activity.
Old House Journal: “Inside Window Rehab”