glass-cutting help

[joan from zone six]

in the past i've had occasion to cut window glass without any big problems - recently came across a batch of 1/4" plate glass (salvaged display case shelves) and wonder if anyone has any advice how to go about making smaller pieces out of big ones ? (other than the obvious hammer)

THANKS !!!!!!

[comfortablynumb]

thick plate like that is tough, the score line has to be pretty deep, and the pressure to break it stright needs a "brake" rig. If it is safty glass, like some new showcases are made from it will shatter if you try to cut it, you need a special cutter to do it, BUT any one who sells glass will do it.
if the plate glass is scratched up... it will be even harder to cut without a shatter.
you can buy a diamon wire saw that cuts glass, they are expensive and SLOW, but the do make a nice cut.
Very old rolled glass thats brittle will snap easy even at that thickness, sacrifice a small chunk and experiment with scoring snapping it. I never could get the hang of it myself, i have my buddy who owns the hardware store cut any cglass I need... he aint much better but he has the cutting rig.

[Beeman]

I worked in a glass shop many years ago. cutting 1/4" plate is no different than plain window glass. We always cut plate on the bench and it breaks just like window glass. Keep your glass cutter in a little kerosene to lube the cutting wheel.
If the glass is safety glass, which is 2 pieces of glass with a plastic sandwich you will have to score both sides as you are cutting 2 seperate pieces of glass. You can tell if it is by looking at the edge. If it is tempered or hardened glass you are out of luck. I remember my Dad trying to cut a piece of tempered glass. After scoring it we did get to the point of hitting it with a hammer and it still wouldn't break. All it took was a slight tap on the edge of the glass and it shattered into fishtank gravel.

[joan from zone six]

thanks for the info -
beeman - is hardened and tempered glass the same thing? do they shatter the same?

[comfortablynumb]

I'll have to tell all that to my buddy, that probably accounts for the ton of miscut glass in his glass room at the store. :haha:

I only know what he"told me" about cutting glass.... thinking back on his other ideas onhow to do stuff, this info doesnt suprise me at all.
sorry for the disinformation joan, just goes to shoe you not to believe the first peroson that tells you how to do something. :no:

thanks beeman!

score both sides.. that does make sense.

I'm gonna kick his.... :yeeha:

[joan from zone six]

mucho gracias, numb - i'll try to get through this little job with all digits intact

[Sparkplug]

Hi Joan,
Years ago I work at a glass plant. I watched it roll down the line the automatic cutters cut it. We were at the bottom of the line to catch the "lites" and pack them in homisite lined boxes.
To cut it just score it, with your pull your glass to the edge of the table and pull it up 2 or 3 inches. Then let it down quickly, make sure that your score is past the edge of the table. It will snap right at the score each time.
Now tempered glass and Heat stregnthened glass Can not be cut
Tempered glass will be good only for the bottom of the fish bowl. H. S. glass will break in big jagged edges. Both of these types you can tell that they have been done by the wavey look when you look at the glass from the edge.
They heat it up slow then cool it rapidly, and usally the cooling will show how the glass came down the roller lines thus the wavy look.
Be very carful with H.S. glass it is very unpredictable on how it breaks. Both tempered and H.S. the strength is in the middle of the glass. I have use a sledge hammer to hit the middle of the glass and it not break. But you just tap the edge and look out baby!!! it will explode.
Tom.