Cut your own Glass – Not as Hard as you may think!

Ever since I was very young, there was one thing I always thought you needed to call in the pros for – and that was for making windows. I mean, how do you make your own windows…you need to actually deal with glass for that! Yup, you’re darn right you need to deal with glass! – And it’s not as hard as you might think. If you buy your glass pre-cut to fit window frames you’ve already made, you won’t have to do any cutting.

But the cutting comes when you go the cheap route and use the second hand stuff. Glass is almost never reused and is usually thrown out when a building or such is destroyed. But if you can somehow get your hands on that glass before it comes in harm’s way, you can potentially save yourself hundreds of dollars. So here’s a list of things you’ll need before attempting to cut your own glass:

(Rather than “cutting” the glass, you’re simply scoring it and then cracking it along the scored line.)

1. A glass cutter. You can find glass cutters at most home centers and it should specify Glass Cutter with Oil Reservoirthe maximum glass thickness it’s made to cut. A glass cutter is basically a tool shaped like a fat pen with a scoring wheel on the tip. Some come with a hollow handle section that carries lubricant. This lubricant is dispensed slowly while you score the glass.

2. A straight edge that spans the entire distance of the glass to be cut.

3. Clamps, if it’s a wide piece of glass. If it’s wider than 50 or 60 centimeters, it’ll be difficult to hold the straight edge during your score. Clamp the straight edge down on both ends holding the glass securely. Don’t clamp down too tight though, as you may break the glass in your zealousness.

4. A rag for cleaning the glass surface. Making sure the glass surface to be scored is clean and free from dirt and other grime is important. The scoring wheel makes a small “scratch” in the surface of the glass and is aided by the lubricant stored in the handle. Any dirt will interfere with this process and can result in the wheel not properly scoring certain parts. This will then heighten the risk of the glass cracking in an undesired direction.

Cutting the Glass

1. Determine the line along which you need to score and place your straight edge accordingly.

2. Clamp if necessary, and perform the score.

It’s important that you complete the score in as smooth a stroke as possible. Completing the entire score in one move is recommended – and easy for a smaller piece of glass. But doing so for a larger piece is more of a challenge. Nonetheless, try to do so in one stroke. If this isn’t possible, hold the wheel on the glass, reposition yourself, and continue the cut WITHOUT removing the wheel. Do not go over your score line a second time! This will confuse the glass and dull your wheel.

3. Once you’ve scored your line, remove the straight edge and align the scored line with the table edge. Apply pressure and crack the glass along the scored line – well, try at least. Theoretically, it should break along the weakest line – which you created by scoring. Problems arise when either the glass wasn’t scored properly or the breaking force wasn’t applied properly – or both. Potential problems are more common as the length of cut increases.

Use the following technique with larger pieces of glass.

The breaking force should be applied on one end of the glass “guiding” the crack along the scored line towards the opposite end. We know the glass should be the weakest along the scored line, but it should also be noted that the 2 ends of this line are even weaker still. In light of this fact, applying the force on one end, causing the initial crack to propagate down along the scored line instead of trying to snap it all in one uniform force is more logical.

Good luck with your glass-cutting and remember to wear protective gear such as gloves and glasses if you’re inexperienced, as small chips of glass may fly in unexpected directions. Once you’ve done a few cuts and have an idea of how the glass behaves when cut, and are careful, you may not need the protective gear. NEVER rub or touch your eyes before washing your hands thoroughly! And taking the edge off of freshly cut glass with a diamond rasp is probably a good idea as well.

– Here’s a couple of helpful videos that show clearly how to do the job. (Note how he cracks the glass from the edges instead of the center. The second video shows how to cut out a circular shape.)


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