Glass Cutting: Making the Cut

March 21st, 2021

Now that you know how to properly use your cutter, it’s time to learn about cutting and breaking your glass. Before we get started, let me clarify something. The term “Glass cutting” is a little misleading because you aren’t really cutting the glass itself. What you’re actually doing is scratching a line onto the surface of the glass, which is referred to as scoring. What this line does is create a weak point where the glass can be snapped apart cleanly.

For anyone wanting to practice at home, I recommend using some scrap pieces of smooth cathedral glass. If you don’t have any scrap glass, then find a fairly inexpensive sheet of smooth glass to use instead.

Make sure you’re cutting weal is lubricated before and after every cut. An easy way to do this is by taking a small scrap of cloth and soaking it in a cap full of wheel cutting oil. Then tap the wheel against the cloth to lubricate it. Also, make sure you’re wearing safety goggles when cutting glass!

To start your cut, put the wheel down on the side of the glass nearest you, as close to the front edge as possible. For this practice cut, make sure there will be at least an inch of glass on either side of the score when you are done to make breaking easier.

Apply enough of a firm downward pressure so that the wheel is able to make contact with the glass without slipping. Pressing down too hard may cause the glass to crack; if your line ends up looking white and powdery, you’re probably pushing down too hard. Pressing down too lightly may allow the wheel to slip or produce an incomplete cut.

While applying pressure, slowly push the cutter forward at a steady and even pace so the carbide wheel turns against the glass. A good score sounds like a piece of paper being torn in half. Make sure to stop your cut as close to the edge of the glass as you can without actually touching it (around 1/8 inch away is a good rule of thumb). Cutting all the way to the edge can cause the glass to crack and splinter, which could ruin the piece your scoring.

NEVER try to rescore a line you’ve already cut! This could cause the glass to break unpredictably, and you run the risk of damaging the cutting wheel. If you’re not confident in a cut you make, just make a new one.