Hey folks. I am preparing to cut four pieces of glass for a display case I
am building. the tops of the pieces will have a slight arc ( 1" over a 10"
run) . I have never cut an arc in glass before, and have limited experience
with straight cuts as well.
I have googled, and found an article where the writer is talking about
turning the glass over so the score is on the underside, placing it on a
piece of cardboard, and applying pressure to the score from the back.
Will this get me the desired results?
If you are wanting to end up with a half moon shaped of glass, the inside
round cut will be tough. You want to remove as much of the glass before
scoring the arc with your glass cutter. Score the line as usual along the
arc and make a few relief cuts out perpendicular from that arc. Then gently
star breaking away. Generally I use grozing plyers to naw away up to the
If you are wanting to end up with an outside radius cut, similar to a ball,
score the arc with the glass cutter and let some of the scores go straight
so that you can break away several pieces as you go around the arc.
PRACTICE FIRST. This took me several tries to learn especially with the 1/2
As far as breaking the glass, I prefer to keep the keeper piece on thin cork
or an old spread out bath towel. With the scored line up and near the edge
of the table quickly press down on the unsupported waste part of the glass.
Remember to make relief cuts as the glass will want to break straight and
this arc cut should be made in about 4 cuts.
nonsense. 1" in 10" is practically straight. cutting it off in pieces would
cause flares, and i would assume that the OP doesn't have the diamond tools
to fix that.
this can be cut in one go. you can get some scrap window glass for FREE at
window places. they toss out lots.
use a sharpie on the back side to mark your cut line. paint the top surface
on the curve with kerosene for a lubricant. run the cutter over the line,
staying on one side of the sharpie line or the other, but be consistent. use
a firm, but not a heavy head. you want to hear a zing, not a crumbling of
the top surface of glass. it doesn't take much with window or even double
run the cutter to the edges of the glass.
there's two ways to break it. 1: place the cut side down on a piece of rug.
press downwards at the end of the cut with the end of a rounded wooden
dowel. it should start to run the crack, and will follow the break. 2: with
cut side up, hold between your thumb and first finger knuckle of each hand.
pull down and away with each hand.
there are glass tools that make this a lot easier. you could also just take
the glass (marked) to a stained glass place. it'll take about 30 seconds to
It certainly will break easier with the relief lines added in. Better to
not take the chance. I have done several stained glass projects and this is
the correct way. Further if the edges are going to show, you can sand the
edges to smooth them up, however I usually do use my wet diamond glass
sorry, i've only been doing art glass work for 20 years, so i'll bow to the
greater knowledge of someone who as a few stained glass projects under their
a 10" piece of a 26" diameter circle is practically straight. yes, it may
break easier, but it will be vastly harder for the OP to clean up the edge
btw: you want to get the fewest, and largest, scrap pieces. the OP probably
doesn't care what happens to the scrap, since they'll probably be discarding
it anyway. doing relief cuts on this is piece is silly and wasteful. for all
practical purposes, it's a straight shot. furthermore, since it's an outside
cut, if it runs, it will run off as a relief would anyway, thus producing
your relief cut. single window glass is very soft, and this type of break is
simple to do.
you want a hard thing to practice on? try cutting a 2" circular diameter
hole out of the middle of a 14" diameter circle of white stained glass.
On Tue, 27 Jul 2004 09:14:35 -0700, "Charles Spitzer"
remove ns from my header address to reply via email
As an interested standby reader of this thread, who is trying to
learn, I would politely ask that you stop attacking Leon. He expressed
an opinion and you denigrated it ("Nonsense"). He continues to
politely talk it over and you start getting sarky.
It's not the milk and honey we hate. It's having it
rammed down our throats.
the advice that leon has given is wrong. it will cause the OP to have a
piece of glass that a: will need fixing using expensive diamond tools and
specialized glass working tools, that for sure they don't have, and b:
possibly be dangerous by having shards of glass sticking out of their
original piece that they will not be able to remove without using such
the method i gave is the correct one, and will result in the easiest and
safest resulting piece of glass for the OP.
for leon, his way is quite sufficient for someone who has the tools to fix
the problems associated with his method. it is neither the easiest, nor
quickest, in my professional opinion. his method would be correct, if for
example, it was a 10" rise in 10" width, which, while not impossible to cut
directly, is somewhat harder than the original request.
As a bit more of an indicator, if that arc that is 10" ling with a 1" rise
were extended into a circle, the radius would be 13". The edge of that
circle would hardly be close to practically straight IMHO.
It does not sound like much curve until you realize that the rise is 1" half
way though the arc and not a total of 1" at the end of the 10" run. So the
1" rise happens at 5" into the run assuming the arc will form a circle. The
waste side of the glass will more than likely break somewhere. When working
with the more expensive stained glass you tend to want the scraps to break
such that you can get more pieces from them also. Making the relief cuts
where you want helps insure that the scrap will be useful also.
Umm, one more thing here, you are partially right to advise using a
lubricant but,,,It is not for the glass. It is common to dip the cutters
into a lubricant to lubricate the AXEL that the wheel spins on. All of my
glass cutters have built in lubricant dispensers that lubricate the axel and
wheel when the cutter is depressed down on the glass. This extends the life
of the axel.
The oil serves two purposes.
From the Warner Crivellaro web site (
Lubricant - Glass cutting lubricant or oil is generally a half and half mixture
kerosene and a light oil. This cutting lubricant serves to
little slivers of glass that cling to the wheel of your glass
interfere with the wheel spinning freely. It also helps
score line from sealing itself which can prevent you from
the glass even though the score line is still visible.
prepared lubricants are available.
Buffalo, NY - USA
(Remove "SPAM" from email address to reply)
Well, hummm,, My instructor 20+ years ago mentioned that the oil was for
the wheel axel. We never really saw much oil on the glass at all. As for
the score line, he told us to break the glass ASAP after scoring.
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