cutting float glass-what am I doing wrong?

[Lonman]

Just started trying to cut a piece of float glass, and every time I try to cut strips; something is wrong. Either it doesn't follow the score or it just like splinters and comes off in pieces. All my cutters are either Toyo or Fletcher-Terry. I've tried lighter pressure too. I've tried using running pliers after the score, tapping the score and breaking on a straight edge. I give up! I am sure it is just me, but I would like to know what I am doing wrong. HELP!!!

[Carol]

Just started trying to cut a piece of float glass, and every time I try to cut strips; something is wrong. Either it doesn't follow the score or it just like splinters and comes off in pieces. All my cutters are either Toyo or Fletcher-Terry. I've tried lighter pressure too. I've tried using running pliers after the score, tapping the score and breaking on a straight edge. I give up! I am sure it is just me, but I would like to know what I am doing wrong. HELP!!!

Are you trying to break a narrow strip off a wide piece of glass, by any chance? It's easier to break a straight run where the glass on either side of the score is approximately equal in width. If you're wanting a series of strips, try scoring strips until you've used up about 1/3 to 1/2 the width of glass. Then break the last score, leaving 2 pieces close to equal in size, one with several score lines on it. Take the scored piece and break it along a score at the midpoint, leaving 2 smaller pieces of equal size. Break each of those separately at midpoint, and so on until you have all your strips broken out. If you're unsure of your pressure try scoring a piece of scrap glass on a bathroom scales. For regular window glass you should be exerting approximately 5 lb of pressure.

[Bert Weiss]

Just started trying to cut a piece of float glass, and every time I try to cut strips; something is wrong. Either it doesn't follow the score or it just like splinters and comes off in pieces. All my cutters are either Toyo or Fletcher-Terry. I've tried lighter pressure too. I've tried using running pliers after the score, tapping the score and breaking on a straight edge. I give up! I am sure it is just me, but I would like to know what I am doing wrong. HELP!!!

There is a simple answer that I'm sure is the culprit. Get some kerosene. A lifetime supply can be bought for a buck and a half (K-1 heating oil). Paint the glass before you cut and I'll bet that buck and a half that your cuts will work. In a pinch WD 40 will also work or you could spend megabucks and buy Bohle cutting oil. When I skip the kero step, I usually get the results you describe, ouch.

I never remember the URL but there is a wonderfull essay by Don Abel on the Morton Glass website. It is in the teaching section and is a downloadable PDF. I have never read anything better on the theory and practice of glass cutting. I have posted about this before and somebody pops up with the URL so it is in the archives.

[Vic]

Is the glass tempered? So it will not cut.

[rosanna gusler]

if it was tempered it would break into two kabjillion pieces. rosanna

[Jane Lindell]

Here you go:

http://www.mortonglass.com/sb01sb80.pdf

Happy cutting!

Jane

[Mira]

One more thing -

I find if my glass is cold, it is brittle. If you're right under an air conditioning vent as you cut, you might want to warm up your glass on a light box.

Sounds crazy, but one winter I went through tons of glass - though I'd lost my touch until I figured out it was the temperature.

Good Luck.

[John]

I would have to agree with Bert, sounds like no oil being used. You can use Kerosene. Also try using a thin machine oil diluted with kerosene. put some in a small container with a piece of felt padding in it. When you go to cut just dip the cutter in the felt and you have oil on your cutter. Try running the cutter up where you are going to cut, NOT using any pressure and you will leave a nice oil trail for your cuuter to go through. Your cutter should also have its own resivoir for oil in the handle.
If the glass is tempered you can still score it, it wil just not break.
BTW that is a neat site.

John

[Bert Weiss]

One more thing -

I find if my glass is cold, it is brittle. If you're right under an air conditioning vent as you cut, you might want to warm up your glass on a light box.

Sounds crazy, but one winter I went through tons of glass - though I'd lost my touch until I figured out it was the temperature.

Good Luck.

Mira

I cut glass in the middle of the winter outdoors in New Hampshire. My 6mm, 10mm, and 13mm glass cases are stored outdoors, so I shovel them out. After scraping off the ice, I paint with kerosene and cut the big sheet down in to a carryable size. The glass I am cutting is actually standing up so that I don't even have the help of gravity to break it.

I think you did lose your touch. It's all in the mind. Except that Don Abel told me that falling barometric pressure can male glass harder to cut. Not low pressure but falling pressure.

[Luiza]

I would have to agree with Bert, sounds like no oil being used. You can use Kerosene. Also try using a thin machine oil diluted with kerosene.
John

I use kerosene too, it´s a lot easier to clean the glass than if you use any kind of oil. Last week I´ve done a piece that used 100 strips 15x0.2 in and lost only a few.
Luiza

[Jerry]

Bert,
Thanks for the Morton tip. However, there's a better explination about failing cuts. It has to do with understanding how the phase of the moon affects the stampeding elephants in Zimbabwe!

Now that you understand my frame of mind, I'll ask the REAL question about the oil/kerosene. I've NEVER used oil in over 20 years and NEVER had any cutter problems or cutting problems. One of my cutters has been with me for 17 years and shows no signs of giving up. Am I the only person in the glass crafting world that doesn't see a need for oil?

Jerry

[Carol]

Bert,
Now that you understand my frame of mind, I'll ask the REAL question about the oil/kerosene. I've NEVER used oil in over 20 years and NEVER had any cutter problems or cutting problems. One of my cutters has been with me for 17 years and shows no signs of giving up. Am I the only person in the glass crafting world that doesn't see a need for oil?

Jerry

Nope. There's at least 2 of us. I have a stained glass business, and stopped using oil in my cutters about 3 years ago. I'm an occasional (very occasional) dipper. That is, I have a rag in a can dampened in kerosene. In the damp months (all 9 of them) I store the cutter with its tip in the can, but that's rust prevention more than anything. About the only time I dip my cutter in the oily rag is when cutting baroque or other heavily textured glass; or when the cutter seems tempermental (err, or is it that the operator seems tempermental) and glass just isn't cutting well.

[Bert Weiss]

Bert,
Thanks for the Morton tip. However, there's a better explination about failing cuts. It has to do with understanding how the phase of the moon affects the stampeding elephants in Zimbabwe!

Now that you understand my frame of mind, I'll ask the REAL question about the oil/kerosene. I've NEVER used oil in over 20 years and NEVER had any cutter problems or cutting problems. One of my cutters has been with me for 17 years and shows no signs of giving up. Am I the only person in the glass crafting world that doesn't see a need for oil?

Jerry

Jerry

I never use oil when cutting stained glass and always use it when cutting float glass.

[Mira]

Bert:

I didn't know male glass is harder to cut. Now it's all making sense!!

[Hugo Gavarini]

My two cents,

I always cut with kerosene, not only painting the score path but slightly dipping the cutter in the fluid. This allows to prevent the tungsten-carbide wheel to carry glass slivers and enables a well lubircated axe.

In fact, the small axe is under a heavy charge when scoring and a bad lubrication might cause a wheel blocking. If the wheel is not spinning the score will not behave as we need.

By the other hand, some float sheets are somewhat more stressed than normal. This produces either easy runnings following the score line or failed cuts to wherever the glass want. A bit of stress might be convenient but over a threshold the glass becomes unstable when cutting. Have you suffered from this phenomena?

[Brock]

Bert,
Thanks for the Morton tip. However, there's a better explination about failing cuts. It has to do with understanding how the phase of the moon affects the stampeding elephants in Zimbabwe!

Now that you understand my frame of mind, I'll ask the REAL question about the oil/kerosene. I've NEVER used oil in over 20 years and NEVER had any cutter problems or cutting problems. One of my cutters has been with me for 17 years and shows no signs of giving up. Am I the only person in the glass crafting world that doesn't see a need for oil?

Jerry

Nope. Haven't used it since 1983. Brock

[Nelson Tan]

Just started trying to cut a piece of float glass, and every time I try to cut strips; something is wrong. Either it doesn't follow the score or it just like splinters and comes off in pieces. All my cutters are either Toyo or Fletcher-Terry. I've tried lighter pressure too. I've tried using running pliers after the score, tapping the score and breaking on a straight edge. I give up! I am sure it is just me, but I would like to know what I am doing wrong. HELP!!!

Hi Lonman,

Use diamond tip glass cutter not the carbide wheel glass cutter.

Our fabrication warehouse uses it everyday. cutting 4 mm to 12 mm float glass and 4 mm mirrors.

example, cutting 4 mm mirrors into 1" strips is easy. no need to tap. kerosene really helps a lot. If you score too deep the cut goes crazy. a light to medium score is best.


Nelson

[Bert Weiss]

My two cents,

I always cut with kerosene, not only painting the score path but slightly dipping the cutter in the fluid. This allows to prevent the tungsten-carbide wheel to carry glass slivers and enables a well lubircated axe.

In fact, the small axe is under a heavy charge when scoring and a bad lubrication might cause a wheel blocking. If the wheel is not spinning the score will not behave as we need.

By the other hand, some float sheets are somewhat more stressed than normal. This produces either easy runnings following the score line or failed cuts to wherever the glass want. A bit of stress might be convenient but over a threshold the glass becomes unstable when cutting. Have you suffered from this phenomena?

Hugo

What manufacturer of float glass do you use? I'm not sure that I have encountered float that is hard to cut because of poor annealing. But it could be that I never thought about it that way.

[Hugo Gavarini]

It's our local Pilkington float glass manufacturer called VASA, their float glass is all over the world because they export a lot. Since they work under Pilkington specifications I believe their glass follows international quality standards.

Once, I had a curious episode with a sheet of such float glass.

I can't assure it was a bad annealed glass. It was interesting to work with. Very easy cuts. In fact, once scored I only had to lift the piece a bit and the score runned all the way almost by itself. But the same "easy" sheet of glass ran twice an odd trajectory, different from the path I had scored. Then I blamed the residual stresses.

[Hugo Gavarini]

"Use diamond tip glass cutter not the carbide wheel glass cutter."

"Our fabrication warehouse uses it everyday. cutting 4 mm to 12 mm float glass and 4 mm mirrors."

"example, cutting 4 mm mirrors into 1" strips is easy. no need to tap. kerosene really helps a lot. If you score too deep the cut goes crazy. a light to medium score is best."


Nelson,

Forgive me my ignorance but, how the diamond tip glass cutter is?
Is it a natural diamond tip, not a wheel?. How can I ask for one of these instruments?. Brand, model?.

I do know the diamond coated rotational tools used to grind or to make holes, and the pointed diamond instruments for engraving.

Thank you,