Knowing how to cut glass can come in handy when making repairs around the house. And if you get adept at it, you can get into doing fancier jobs, such as making stained- or patterned-glass creations. To get started, all you need is a carbide-tipped wheel cutter, a straightedge, and a little light oil if your cutter isn’t self-lubricating. And don’t forget to don work gloves an safety glasses.
The technique will be familiar to you if you’ve cut drywall before; you’re scoring one side to weaken it, then bending it to break it.
Try it out on a scrap piece until you get the hang of it.
To keep the glass nicely cushioned and in one place, put a damp rag on a smooth, flat surface, and lay the glass on top. Clean the area of the glass you’re going to cut by running your finger along the surface. Measure and mark your cut with a marker, or a special glass marking pencil. Lay the straightedge along the line (allowing for the cutting wheel’s offset), and tape it in place with duct tape. If your cutter isn’t self-lubricating, put a drop or two of lightweight oil on the wheel.
Now, firmly draw the cutter along the straightedge, putting just enough weight on it that you hear a clicking, gritty, scratching sound. Score the line only once.
If you wish, flip the glass over, and tap the opposite side of the score with the ball on the glass cutter – though this isn’t always necessary. A simple, crisp “fold” of the glass will do the trick in most cases.
If the glass doesn’t break easily, stop. Try again, but score a new line. Once you’ve practiced on scrap glass till you have the hang of it, you’ll do it right every time.
Once the glass is separated, sand the edge with fine sandpaper or buff it with a sharpening stone so that it’s no longer sharp enough to cut. This will also make the glass less likely to chip.