Unfriendly White glass

[Ron Coleman]

This weekend I cut 8, 5 inch squares of BE Lacy White glass (3mm, single rolled) and dusted the rough side with some powders. I didn't have any problems cutting the squares. The pieces (single layer) were fired to 1425 and annealed by overnight cooling.

This morning I started to cut the big squares into 1 x 1 pieces and broke the first three. Nothing I did would cut the glass, not even my Toyo Tap wheel cutter. Thinking it was an annealing problem I put them all back in the kiln and reheated and did a 30 min anneal.

This afternoon I started to cut again and had the same problem. Out of desperation I cut one of the pieces from the back side (the shelf side) and it cut like a dream, at least for white it was a dream. Strange stuff.

I did find cutting was color sensitive, red and yellow powder on the white was like cutting cast iron, it just didn't want to work. I couldn't even tap a run in the glass. It's really bad when you can't get a 5 inch long cut to work.

Turquoise and light jade green on white cut from the smooth side without any problems at all.

Is it possible there is a local tempering or something going on between the colors?

Ron

[Lia Howe]

You asked about other colours. I have been cutting glass for 13 years. I did stained glass first then fusing then hot. I find that lots of other colours cut different. I use a lot of Spectrum glass for stained glass and I teach with it but lots of colour cut better than others. I find that pinks and yellows really hard and sometimes uncooperative. Blues cut like butter. Greens -it all depends if its transparent or opaque. Some would say that it is all in my head, but I have cut enough glass that If having this mind set gets me to use more caution when cutting helps me to have less cursing and breakage. Fusing glass is a whole other story. Bullseye can be a bitch. Mainly because you are fighting the rippley bubpy surface. If you lay a tougher glass on to of a "softer" glass I have found that It can be tricky to cut. When in doubt or lots of breaks I use my saw. An expensive toy but it can save lots of aggrivation. Hope this helps. It may not be based on scienific fact but this helps me.lia

[Barbara Muth]

Ron, I have often wondered if it is more difficlt to cut glass that has been fused because of trapped bubbles interrupting the running of the score. That would explain why maybe it was better cutting from the bottom if you had fused on a sheet of glass and trapped bubbles that rose near to the surface, but you fuse powder which would presumably have allowed the air to escape. So my theory is useless. I have found lacy white to cut pretty easily, but I usually use it in thin and not normal thickness.

You have me curious now, I will have to run some tests next time I work with the lacy white!

Barbara

[David Williams]

This weekend I cut 8, 5 inch squares of BE Lacy White glass (3mm, single rolled) and dusted the rough side with some powders. I didn't have any problems cutting the squares. The pieces (single layer) were fired to 1425 and annealed by overnight cooling.

This morning I started to cut the big squares into 1 x 1 pieces and broke the first three. Nothing I did would cut the glass, not even my Toyo Tap wheel cutter. Thinking it was an annealing problem I put them all back in the kiln and reheated and did a 30 min anneal.

This afternoon I started to cut again and had the same problem. Out of desperation I cut one of the pieces from the back side (the shelf side) and it cut like a dream, at least for white it was a dream. Strange stuff.

I did find cutting was color sensitive, red and yellow powder on the white
was like cutting cast iron, it just didn't want to work. I couldn't even tap a run in the glass. It's really bad when you can't get a 5 inch long cut to work.

Turquoise and light jade green on white cut from the smooth side without any problems at all.

Is it possible there is a local tempering or something going on between the colors?

Ron

Hey Ron You were on the right track just the wrong direction. Any glass you plan to cut should be under annealed. You want it to have stress in it. Not too much, or your break will run out at the corners. But well annealed glass is extremely hard to cut.