Using running pliers
I often have folks come by who are experiencing extreme levels of frustration with their cutting, even with straight lines. Most people are using the good old metal running plier:
This tool has a curved jaw, about 1 inch wide, and a screw on top to set depth. It also has plastic covers on the jaws:
Don't remove these! This type of running pliers will easily break 1/2 inch strips of glass if used properly, and will pop down to 3/8 with judicious use. Here's the secrets:
Don't choke up on the tool. You can apply even, steady pressure by holding the tool handle as far back as possible. This is of extra interest to those who have small hands. Leverage is your friend! If you choke up on the tool, you will get frustrated, give the glass a sudden squeeze and KABLOOIE!, you broke it.
Leave the plastic tips on (note the emphasis on this point?). Metal against glass in this type of situation is disaster.
Make sure the screw is on the side you scored. I don't really use the screw for depth setting, but I do use it to remember which side is up.
Listen carefully. You will hear the glass crack on some glass, but it won't go all the way. This happens a lot on thicker glass (collage glass like Bullseye Hollyberry comes to mind.) Just move to the other side of the piece and run the break from the other end. Voila!
Run swallow curves with a runner. You can run shallow inside and outside curves with your running plier too. Just listen carefully to the glass.
The metal running pliers is the most versatile tool in your glass cracking toolset, bar none.
Author's note: The above does not apply to the plastic version of the running pliers. I really dislike the plastic version as a general rule because the jaw design limits your strip breaking ability to above 1/2 inch, usually more like 3/4.
