Glass Cutting How To's

[Kelly Thorson]

While gathering some reference material for a young fellow I came across the following videos on YouTube. If you are fairly new to cutting glass they cover it well.
basic glass cutting
circle cutting

[DAVE SMITH]

Hey Kelly that's funny seeing this video. The guy cutting the glass is my friend James who owns Creative glass in Bristol UK. I went on one of his fused glass courses a while back to gain some experience with kiln work.
Thanks for posting it here.
Dave

[Kelly Thorson]

It's a small world Dave....the internet makes it much more so....it looks as if he has lots of know how to share.
If I ever get over there I'll have to try and check out his space.

[Wayne Osborne]

He makes that look so easy!- Glass is a truely strange material and so versatile.

(is he always that tidy in his work Dave?)

[DAVE SMITH]

Yes he always seems clean and tidy Wayne.
Dave

[Patrick Mackle]

I hope someday that somebody shows cutting techniques on some thick glass, say 3/8" up to 3/4".
Thinner art glass is a good way to demonstrate in theory, but skill really matters most when thick glass is involved.

Unfortunately years ago, I was only able to see the finished results of a highly skilled glass cutter that my friend hired to cut a large number of circles out of
1/2" plate glass. This man scored the circle, then ran the cut with the aid of a gas torch. Then he made a single cut at the closest area
between the circle and the edge of the glass.My friend said that he made a cut on the thickness edge of the glass, not the face surface. After running this short cut, he used his fingers to expand the outer waste glass like a ring in one piece and
lift it away leaving the required circle neatly on the table. When he was finished he left only two neat stacks of glass, one were the circles and the other
was an astounding stack of waste glass, each neatly intact with a single 1" split and a perfect circle missing from its center. There were in excess of 100 circles of glass.
The circles all had nice clean square faces, no flairs or chips. If they had not been cut and run so perfectly, he would not have been able to lift away the
waste glass so neatly. It was the work of a true master glass cutter. I only wish I had been there to see him in action.
I should include that these circles were 24" in diameter.

Pat

[DAVE SMITH]

Hi Pat .
It's interesting reading your post. I have a friend who is a glass cutter , I have him cut my glass and some of the pieces I see him cutting as you have discribed is exactly the same ,he also uses a blow torch etc
I took Doug Bernhardt to see him once ,he only demonstrated to Doug with a small piece but you could tell he had been cutting all his life with the amount of confidence he had. He's a very good fisherman also.

Dave

[Doug Bernhardt]

I remember him well Dave. Very professional and wish now I'd seen him doing some thick circles. I was trying to work out if that was actually him in the video, but I didn't remember him having that accent. It seems to me you were being a cheap-skate as usual and hitting him up for free stuff. No wonder he was more interested in showing you the door! ;=)

[Patrick Mackle]

Dave,
Of course I had to try to duplicate the cutting that I had seen this man do when I returned back in my own shop. I did have some success using the torch to run the score in the glass,
however I sure would like to know for sure were Exactly to apply the heat. AS in "behind the run, beside the run, and whether I should be heating the scored side or the opposite side. As I said, I did have a fair degree of success using my own trials, but never could feel confident that I had figured it out properly. I certainly wouldn't be
able to cut 100 perfect circular thick pieces!!
Being that I did not view the method first hand, I also don't understand if the torch flame is actually used to run the score, or if it is only used to expand the glass, and then run the actual score by the traditional manually applied hand/tool pressure. Also, does your friend cut a "nick" to run at the glass' edge (thickness) to separate the outer waste glass from the circle, or cut radiating lines to break out the circle?

Pat

[Kelly Thorson]

Hi Pat,
Here is a quote from the Fletcher-Terry website another source of glass cutting info.
The application of a concentrated intense flame along the score will deepen the fissure by causing abrupt, local expansion. Success with flame running is even more artful than the other methods and requires trial and error practice before consistent success can be expected. It is very important to observe safety rules required in the use of gas flame equipment.
I remember my father using a propane torch to "chase the bead" when cutting glass. He also made his kids a jig that we scored bottles in and then filled with hot water and ran an ice cube around the score to make drinking glasses...of course the edges were far to sharp to use.
There is some very good info here on wheel angles, sharpness and types of glass and thicknesses if you are really interested.
TRIVIA: The apex on the wheel of a glass cutter has a pressure of 100,000 lbs/sq inch.. ...amazing huh?

[Patrick Mackle]

Thank you Kelly. I've been to their site before. It doesn't mention which side of the glass to heat, but it did mention applying "intense heat".
I experienced some pretty good results in my trials, but I wouldn't say that I used intense heat. As soon as can get a chance, I'll try it again
with a hotter flame. I seem to remember seeing regular propane torches around the cutting table areas of some local glass factories and believe that they use them in that procedure. I've tried both propane and acetylene, just need to turn 'em up higher.
Pat

[DAVE SMITH]

If you remember Doug he showed us the door after I mentioned you were Canadian, plus he phoned me a few days later and asked me not to bring you there again as he could'nt understand your accent.
I will try at some stage try to video him cutting thick glass and upload it on Youtube. Get some answers today if I can Pat.
Dave