Cut Glass like a Pro
By learning to cut glass – and by keeping a sheet or two of the stuff in inventory at all times – you can handle emergencies quickly and simply. When a Sunday afternoon ball game breaks a window, you can simply dip into your inventory, cut a piece to size and replace the broken pane right then and there. The ability to cut your own glass also lets you create any odd shapes you might need, such as ellipses or circles for picture frames.
And despite what you might think, cutting glass is not a very difficult skill to master. All you need is a simple $1 glass cutter, and a little practice on some scrap glass. Start by lubricating the cutting wheel on the cutter with a drop of light oil. This will help it roll evenly across the glass and prevent skipping. Next, place a straightedge along your line of cut and hold it firmly in place. Always place the straightedge on the ”good” side of your line of cut. Then if your cutter happens to stray away from the guide, it will stray into your scrap, not into the piece of glass you want to keep.
Place the cutter next to the straightedge and draw it toward your body in a firm, continuous stroke. If you use the right amount of pressure, you’ll hear the cutter make a scratching sound as it scores the glass and you’ll feel a bit of drag on the tool as you draw it along. If you use too little pressure, the cutter may slide or roll freely. You’ll feel no drag and hear no scratching sound. Or the cutter may work intermittently, skipping and scratching across the glass. If you use too much pressure, the cutter will ride roughly across the glass and may even break it, especially near the beginning or end of the cut.
Practice using the cutter on scrap until you can make nice consistent score marks. Once you get a good, clean score, place it over a dowel or along the edge of the table and press down on the glass to break it along the line. Always keep the score up when breaking the glass. Cuts near the edge of a piece of glass can present special problems. When you try to snap off the narrow scrap, your break line will have a tendency to veer off across the scrap. There are a couple of tricks to help avoid this: After making your score, tap the glass lightly along the score line with the handle of the cutter. Tap the side opposite the score and keep an eye on the score line as you tap. You should be able to see the glass crack slightly along the score line. If not, tap just a little harder until you do see the crack start to develop. Keep tapping along the line until the crack runs from one end of the score to the other.
Place the glass, score side up, on a table, with the scrap hanging over the edge. Hold the glass down with one hand and grasp the scrap with a pair of pliers in the other hand. Then you can just snap the scrap off with a downward, bending motion.
If all goes well, the scrap will snap off in one piece. If not, nibble the remaining scrap away with the pliers. If your scrap is less than half an inch wide, you may have to do a lot of nibbling. The narrower the scrap, the more likely it is to break into a lot of small pieces. Scraps much narrower than a quarter of an inch are very difficult to break off without a lot of nibbling. You’ll probably end up with a rough edge, or, even worse, you’ll break the glass. That’s why it’s important to cut glass to the right size on your first try.
Cutting Curves
This isn’t much harder than cutting straight lines, except that you usually have to work freehand. You can draw your line of cut on the back side of the glass, or draw it on a sheet of paper and put the glass over the sheet. Then place your cutter over the line and make your score. Try to use a single continuous stroke. After scoring, tap the score line as described above. Then break the glass. It should break cleanly along the score. Circles and ovals are a bit trickier. Draw your pattern on the back of the glass or on paper. Make your score as just described for curves. Keep the edges of your circle or oval in at least a half inch from the edge of the sheet you are working with so you don’t have problems with scrap. After making your score, make at least four more score lines running out from the score line to the edge of the sheet of glass. Space these lines evenly around the perimeter of your oval or circle, at 12, 3, 6 and 9 o’clock, as shown in the sketch. Now tap all your score lines with the handle of the cutter, looking for the telltale signs of cracking.
Next is the tricky part – breaking away the scrap glass surrounding your circle. Breaking away the first piece is the hardest. Look at your score lines and coat those that seem to be most evenly scored and cracked. Grasp the scrap between y our best score lines with a pair of pliers and break it off. Once that piece is off, the others will come easy.
If you succeed on your first try, consider yourself a master glass cutter. If not, try again. You’ll probably get it on your second attempt.
