The only safe and permanent way to fix cracked glass is to replace the glass. A crack in the glass compromises the structural integrity of the pane, and it’s much more likely to shatter if it is subjected to stress from wind or temperature changes.
Applying tape (masking or packing tape) over the crack on both sides can help keep it together and also keep water from getting in for a little while but again, this is only a temporary measure. If you notice more then one crack, it is best to just remove the glass completely and cover the opening until the glass is replaced.
Replacing a broken pane in a newer insulated window is something to be left to a glass repair technician. Replacing single pane glass from older windows may seem easier, but it requires a multitude of steps from removing putty and glazier’s points, to installing the glass and replacing the putty and points. Contact us for your window glass replacements in Milwaukee.