Q. How do I cut glass to repair a broken window pane?
A. Generally speaking, picture-framing stores and certain hardware stores, such as Lowe’s, will cut new glass to spec for a very reasonable fee. However, you can also cut it yourself using a handheld glass cutter. The cut should be made at least 1/2 inch away from the edge of the glass. Place the glass pane on a very flat, solid surface, padded with layers of newspaper. Using a framing square as a guide, draw a line with a grease pencil along the cut line. Then, using the square as a blade guide, score the glass with the cutter. (The tool is not meant to cut completely through the glass.) Align the scored line with the edge of the framing square and tap the score with the handle of the glass cutter to snap it off.
