View Full Version : Tempered Glass question

Art Crowe
09-09-2006, 10:24 PM
Has anyone out there had success laser engraving glass and then having that glass tempered? I noticed a previous thread that mentioned difficulty while trying to laser tempered glass so I'm guessing that is out of the question.

http://www.sawmillcreek.org/showthread.php?p=410158#poststop is the link to the "Stuff you should never try to" post and Guy made a comment about tempered glass there.

Thanks for any thoughts on this one!

Perry Holbrook
09-10-2006, 10:39 AM
I'm not a laser person, but I am a glass person. When glass is tempered it is heated and cooled very quickly. This causes the outer skin of the glass to put the inner core into a stressed state of compression. If an additional stress is added the glass will shatter rather easily. I would think that is why a laser after tempering is not a good idea.

On the other hand, if lasered first, I would GUESS that it would work. The main concern would be if the laser induced stress into the glass while working. The rapid heating and cooling will break glass if it already has stress.


Art Crowe
09-10-2006, 2:36 PM
Perry, Thanks a bunch for your response. If you deal in glass, do you have any estimated costs associated with tempering? How is it usually priced (square feet, thickness, per hour, etc.)? Also, what would a fair price be? Thanks!!


Perry Holbrook
09-10-2006, 3:02 PM
Art, my hands on experience in glass is what's called warm glass. This means I fuse multiple layers of glass together with added color in a kiln that runs at about 1500F. The end result is a glass tile which I use in the
the other products I make in the studio. My web site is kopperwood.com.

I have not had any of my pieces tempered, it is not possible to temper fused glass due too the small air bubbles that are inside the glass.

However, I do know that my local glass supplier can send off items to be tempered. His place is the kind of place you would go to to get a glass table top, shower enclosure, etc. You probably have something like that near you.

BTW, the tempering process heats the glass from room temp to 1100 F in 5 minutes and cools it back down in another 5 minutes. The machinery cost around $2 million.