To start, you need a flat clear surface, preferably with an old towel or some kind of fabric laid over the whole surface at least the size of the sheet of glass that you are going to cut, a straight edge that is at least as long As the longest side of the glass to be cut, a glass cutter, some white spirit, a few cleaning rags, a measuring tape, a marker pen, some pencils or dowels at least adding up to in length as long as the longest cut to be made, maybe a few bandages, and the phone number of the local hospital. Only joking about the last two! It's really simple.
Lay the glass on the towel or fabric surface of the table, ensuring that the glass is spotlessly clean, you can wipe it with the rags and a bit of white spirit. Then measure where the cut must be and mark with the marker pen at either end of the cut line. Align the straight edge with the marks, you should have the glass cutter in your hand at this time, and ensure that the center of the cutting wheel lines up exactly with the mark which represents the cutting line. The cutting line should be liberally lubricated with white spirit, and spotlessy clean, any dirt here could interfere with the scanning process, and cause the glass to break along lines that are definitely not in your plan. Now, when you are absolutely certain that all of the above is how it needs to be, grip the glass cutter firmly and start to apply a light but firm pressure just off the edge of the glass, this is best started away from you, so that you draw the cutter towards yourself as you cut the glass. Here is where you must understand that the term "cutting glass" is not really what you are trying to do at this point.
What is required is rather a scoring of the surface. When you apply pressure and bring the cutter towards yourself, you should hear a kind of light scratching sound, that does not sound like cracking, and should be a constant sound all the way across the sheet. It is imperative that you get this right the first time, because you can only do this once, as any pending scoring will almost certainly cause the sheet to break on the next step. Now you need to place the pencils (s) or dowels directly under your score line, and then apply firm downward pressure either side of the pencil to snap the glass along the score line. If everything has been done correctly, it will break along the desired line with a very satisfying "crack" and you'll end up with just two pieces of glass. If it goes wrong, you'll end up with either one piece, but with cracks all over, or more than two pieces of irregular shape. Whatever happens, keep trying, because it's not rocket science, and when you get it right, it is extremely satisfying, and large sheets of glass cost far less than small pieces (per square of course). When you get really good at it, you can do away with the pencil part, and just grab the sheet and "bump" it on the edge of the table along the score line, and it will snap cleanly in two.
With this method, you can only cut straight lines, I will cover cutting circles, curves and even deep inside curved cuts in future articles, so if you're interested, keep an aye out. I do not do this any longer, but if you really need some one to one instruction, please feel free to drop by here Walvis Bay Lagoon Where I'll be pleased to help you out.
Source by Gary Gee