Glass cutters.

[Fat ferret]

What’s the best way of cutting 4mm single glazing? I want to make a load of old odd shaped panes into 200x250mm panes. I have used the cheap silver line wheel and oil cutters with indifferent results but maybe that was my technique. I see there are glass cutting wheels for grinders. Are these better than the wheel type cutters?

 

[Rorschach]

The problem with grinders is heat buildup which can cause the rest of the pane to crack. Wheel type really are the best for this but you need good technique. One single hard cut, no double cutting and a good flat surface for cutting and snapping on.

 

[Jacob]

Glass needs to be really very clean along the cut (doesn't take much to send the cutter off line), ideally resting on very flat table bigger than the glass, with fabric or paper table cover, and one straight gentle stroke with wheel cutter dipped in oil, along a firmly held straightedge.
Put the cut on the edge of the table to snap it by gently increasing pressure. Maybe a bit of practice first? You get an idea for when it's going right - you get a hiss rather than a scratchy sound.
I've got an "oil" cutter with oil in the handle, but it's never cut very well and instead I've used a very ordinary one I've had for many years.
Glaziers pliers are handy.

 

[Phil Pascoe]

If it's old and /or used glass you'll be luck to cut much of it cleanly regardless what cutter you use.

 

[Jacob]

I've cut acres of old glass, all sorts including blown, embossed etc etc. Never any problem - virtually always cuts as new. Has to be very clean where the cut is being made.

 

[screwpainting]

For consistent results, use a hammer and bolster. 8)

 

[tony_s]

The guy in the glass shop near me uses a cheap looking glass cutter, certainly nothing fancy, which he dips into white spirit before making the cut. Not sure what the white spirit is supposed to do....

 

[Jacob]

The guy in the glass shop near me uses a cheap looking glass cutter, certainly nothing fancy, which he dips into white spirit before making the cut. Not sure what the white spirit is supposed to do....

It cuts better, I don't know why. I use thin oil.

 

[Fat ferret]

Right I didn’t clean anything last time, though I’d clean it if I managed to cut it right. This time I will clean it properly and see what happens. Do you score both sides or just one, once or repeatedly?

 

[Phil Pascoe]

One side once.

 

[Doug71]

It is always easier to cut off say 75 mm as opposed to say 10 mm. If it does not snap easily you can hang it over the edge of the bench and gently tap it underneath the cut line with the glass cutter (some have a metal ball on the end for this very purpose). You will see the cut/crack appearing but you will not get as clean edge as if you just cut and snap.

Glass cutting will soon be another forgotten skill alongside pointing putty.

Doug

 

[sunnybob]

I have cut quite a lot of glass (I used to make aquariums), and had a friend who had his own glazing business.

The best cutter is a diamond. Wheels are ok, but they get blunt and you never know when untill you ruin an important pice of glass. I have two diamond cutters that belonged to my dad, and he died 40 years ago. Still sharp.
https://www.ebay.co.uk/itm/HIGH-QUALITY ... xy039TKrwQ

A diamond cutter does not need the white spirit. You can use that to make sure the glass is spotlessly clean along the cut line.
Use ONE firm consistant pressure stroke from end to end. never go over a cut, not even to nick the ends.

If youre brave and / or experienced, you can hold the sheet up and snap it with your hands. My friend could make a 4 ft long ragged edge icicle this way. I was never quite that brave.
As a newbie, and assuming the cut isnt massively long, the best way to snap it is to place the glass on a flat surface with a towel or bedsheet underneath (to stop grains of sand or similar impacting the glass), put a matchstick at each end under the cut and in line with the cut. Then slowly and gently increase pressure either side with your hands.

 

[Phil Pascoe]

The best cutter is a diamond. Wheels are ok?
I dealt with large glass firm regularly for a while when doing some dichroic glass work and they sold the cutters that ALL their men used day to day on all types of glass - they were Japanese oil filled wheeled cutters (I've still got mine). I was a bit surprised and asked about it and they said they were unquestionably better.

 

[Jacob]

The best cutter is a diamond. Wheels are ok?
I dealt with large glass firm regularly for a while when doing some dichroic glass work and they sold the cutters that ALL their men used day to day on all types of glass - they were Japanese oil filled wheeled cutters (I've still got mine). I was a bit surprised and asked about it and they said they were unquestionably better.

I've got one but it doesn't work very well. Maybe a dud.
Wheels good, diamonds best.

 

[Lons]

I did the same as Phil and bought from the glazing company I regularly used, same as they used themselves and cost me only a fiver though may have been trade price as I was buying a fair number of d/g units at the time.

I've always found old glass is more difficult to cut than new and if you ask the pros they'll tell you the same. I've asked that question several times and I believe the guys who cut for a living every day.

As said though must be spotlessly clean along the cut line and only one pass with the cutter.

Bob

 

[Jacob]

...
I've always found old glass is more difficult to cut than new and if you ask the pros they'll tell you the same. I've asked that question several times and I believe the guys who cut for a living every day....

I'm a pro (or I was) and I can tell you that old glass is not a problem at all. I can see it might be a problem in a shop which does mostly new and has to adjust to the slight differences of old glass - the main one being having to clean it. It's also a problem in being in smaller sizes having been recycled, so there is more wastage. I usually cut off the puttied edges complete - which is where problems can happen with little spelches and incipient cracks etc

 

[Phil Pascoe]

If you have a table saw or even a router with small cutters, if you need to cut off very narrow strips cut a groove the same width as the thickness of your glass but slightly shallower and use this to snap it off after scoring. Much easier and safer than trying to use pliers.
I made several of these boards for people I did courses with.

 

[Jacob]

Looks a good idea.
Glazing pliers work once you get the hang. You have to apply a gentle bit of pressure - sometimes moving along and ease it - keeping an eye on the cut. You can see it suddenly deepen before it actually breaks. If it doesn't show then move along. More force might not be enough.When you get good at it you can break off a 5mm strip from the edge of a large pane, in one piece.

 

[Lons]

...
I've always found old glass is more difficult to cut than new and if you ask the pros they'll tell you the same. I've asked that question several times and I believe the guys who cut for a living every day....

I'm a pro (or I was) and I can tell you that old glass is not a problem at all. I can see it might be a problem in a shop which does mostly new and has to adjust to the slight differences of old glass - the main one being having to clean it. It's also a problem in being in smaller sizes having been recycled, so there is more wastage. I usually cut off the puttied edges complete - which is where problems can happen with little spelches and incipient cracks etc

Wouldn't dispute that Jacob but the guys I spoke to said different and they're the ones I know personally so with all due respect!
Just to be clear though in their case they also clean new glass before cutting, never asked if that was usual practice in the industry however but they do it and I've witnessed it.

I haven't cut the "acres" of old glass you have but have done a fair bit and I certainly found it more difficult than cutting new.

cheers
Bob

 

[Chippyjoe]

Well never thought I would agree with Jacob on much, but must agree cutting old glass is not difficult, ok it is more brittle than new but 99 times out of a 100 it can be cut ok.

I have cut hundreds of sheets of new glass in a past life and always used and still have my trusty Toyo glass cutter (Japanese). The hairiest glass to cut were full sheets of obscure glass , I did have a couple sheets break whilst lifting them to the cutting bench that makes your backside nip up :shock: .