I need to cut about 1 1/4" off the bottom of the door glass in my truck (shortening doors and moving door sill up ~8"). Thinking back to middle school shop class, I remembered using a scoring tool on some glass. Dug around the basement, found one, scored myself a line on the glass, tried to break it, and promptly shattered the whole damn thing. :( So, once I find a new one at the yard, how do I go about cutting it without shattering it?

Anybody got a cheap (scratched OK) driver's window for a '73-'87 C/K (-'91 R/V) Chevy truck in Denver?

Pete

I don't think you can cut tempered glass?? That's what temper glass doesn, it keeps glass from breaking in large and dangerous sheets of glass. You may be stuck with it, or you might have to go to a glass shop and see if they can do it for you. :confused:

seems like your best bet might be to actually 'cut' the glass. probably use a cut off wheel in a grinder or small hand saw. several passes over a spot and you could eventually cut through. might lightly clamp a 2x4 to it to use as a guide. i'd definitely use eye protection and probably a respirator too ... glass dust doesn't seem kind on the lungs.

- jack

easiest way is to tape off what you want to keep and use a sandblaster with a fine tipand go back and fourth . It worked on a fullsize chevy windshield and door windows! :D

Some glass shops use a large belt sander with a special belt on it and sand it down to the needed size. Go to your nearest glass shop and see if they san do this.

GREEN WAGON is right!!!!
THIS WORKS ON WINDSHIELDS (I've never cut door glass)
Mark a line where you want to cut then Tape off the side you want to keep with duct tape. put 2 or 3 lalers and make sure its pressed on good. Be sure to tape both sides.You will need to own,rent,or buy a sand-blaster and air-compresser(do this outside!!!!!!!!!!!!!!!!)Blast back and forth keeping the gun moving, and feel the glass with your hand every few minutes DONT let the glass heat up,if does it will crack.Once the front is cut down to the safety rubber , flip the glass over and repeat.Use a razor blade to cut the safety rubber off.After your done take the glass to a glass shop and have them polish the edges (if you dont it will crack)it should cost around $20.
practice on a junkyard glass John

GloNDark is right about you not being able to cut tempered glass. I know this because I am a professional glazer (commercial window installer). Tempered glass will shatter when cut. I haven't had much experience with auto glass, but I would try the sander approach. I know we have cut down several pieces of tempered glass with belt sanders and a special belt. I don't remember where we get the belt, or what grit they are, but try calling a glass shop and see if they can help. Good luck

All I can imput, is wear heavy leather gloves, heavy long sleave gloves. When safty glass pops, it will shred you to hell! I know quite well! Safty glass is cut, and then temppered, so sanding/sandblasting is your best bet!

there is no way to cut temperd glass. it is cut to size then temperd. you can how ever cut laminated glass ie windshields. you have to score both sides run the score then heat the lamination material between the glass, usualy done with a flamable liquid like denatured alchole.

as far as grinding it the only thing you can do is polish the edge. go to far with the polish and pop shatter into millions of pieces. the edge of tempered glass is its weakest point.

have fun

jeff:usa:

Air-tempered glass is heated to ca. 700 degrees and then quickly cooled with air. This creates a thin skin around the surface of the part that is under a lot of tension; you can see the effect with crossed polarizers. Chemically tempered glass is submerged in molten salt (usually sodium or potassium nitrate, depending on glass type) and soaked for 8-12 hours, then cooled slowly. This through-hardens the glass and causes microstructural changes throughout the depth of the material. Chemically tempered glass is superior in strength, although a lot of places still use air. Again, the only way to be sure is to check with crossed polarizers and look for a cross pattern. Air tempered glass can be annealed in a big oven, and then cut and re-tempered. Chemical tempering is pretty much irreversible (ie. it'd be a lot cheaper and better to just start over). Laminate can also be cut with a wet saw, but the glue gums up the blade badly and you've got to stop and clean it often - otherwise it'll get hot and break the glass.