Glass Cutting - How to?

Go get a glass cutter - you can get at a hardware store or hobby shop, perhaps even a glass store.



Glass cutting isn't as hard as it might seem, as long as you have the right instructions. Nobody is perfect with glass, but you can get it right nearly every time. Here's how to cut 1/8" (3.1 mm) clear glass, also known as "double strength" (DS), which is probably the easiest to cut, as well as the most common.
This method has dimensional limitations. Cut cannot be very long, e.g. 24 inches is long, and failure rate is too high. Also, the pieces to be cut have to be wide enough, minimum some 6 inches perpendicular to the cut.

[edit] StepsClean the surface, but only along where you plan to score. Any grime or silica (the substance that makes two pieces of glass slide on top of each other to prevent scratching) will ruin your score and make you think you cannot cut properly. Just run your finger along the surface of the glass where you plan to score.
Obtain a glass cutter and some light oil. You can buy cutting oil at a stained glass store or use a small amount of kerosene. Dip the cutter in the oil before you score the glass. An oiled cutter creates a smoother score line.
Grasp your cutter like a pencil. Make sure to look at the wheel and its orientation to the glass and align it properly. This is a very simple grasp to achieve, so do not unduly complicate it.
Use a scrap piece of glass to practice on. Apply pressure to the glass as you pull the cutter along the surface, rolling on the small carbide wheel. The score must run from one edge of the glass to the other edge. Listen for a smooth sound like ripping silk. A gritty sound means that you are pushing too hard or that you did not oil your cutter. The less sound you make, the better your score will be. If you push too hard (a very common mistake), your cut gets "hot", meaning that it snaps and pops. Try it and you'll see. You are aiming to get a uniform score. If you are pressing too hard in one spot and perfectly in another, the glass will not break the way that you want it to. Microscopic imperfections in your score will cause your cut to go askew.
Score along a straight edge. Use a yardstick (meter ruler) or a normal desk ruler. Use something that has a high enough profile so that it won't conflict with the wheel on the cutter, as would a ruler with a thin metal edge.
Practice on scrap glass until you're ready for the real thing. You'll have a score that is not popping and is barely visible if you were to wipe the oil away. It should look like a small scratch, that's all, nothing more.
Grasp each side of the cut as if you were trying to break a potato chip in half with two hands. All it takes is minor pressure. It is all in the wrist action. Your elbows do not move. Simply twist your wrists (your right wrist will turn clockwise and your left will turn counterclockwise). Imagine that the score you made is half the depth of the glass and now you need to "open it up" by using the score as a weak spot.


Note: It may simply start as a "run." A run is where the glass is starting to break along your score. It may also run the entire length of your score. Either is fine. If it only runs an inch (2.5 cm) or so, apply a little more twisting pressure and it will continue to run. You're done as soon as you have two pieces of glass instead of the one you started with.
Use fine sandpaper or even better, a sharpening stone, to remove the sharp edge. This edge will be where the vertical edge meets the horizontal surfaces. Not only does sanding reduce the chances of your being cut but sanded glass is less likely to chip along the edges and has some added strength

I tore down a sun room built of standard panels of insulated glass and seperated the sheets. Those are tempered and you cannot ever cut them as i knew first had but still attempted a cut with an expensive $50 glass cutter. I also tried a Diamond rotating 4 " blade. That too was a total failure.

The glass crumbled into 1/4 inch square and made a mess. I tried at least 4 or three panels same crumbling and mess.

You cannot cut them ever as they are made first of standard "hard" glass cut to size, then sent to an oven and tempered as final processing. The structure of the original glass is such that it turns to a safety glass so that if it is broken it will crumble to a million small pieces which are not sharp and avoid serious injury to people. .