kcress
New member
Tempered glass makes lots of sense.
It's three times stronger than untempered glass. It also is five times more resistant to temperature shock. This means ANYthing made of tempered glass can weigh about 1/3 as the same thing made from untempered glass and the maker gets to use 2/3s less glass building it. It also is very dang hard to actually break. But using tools, ignorance, and perseverance, you can do it! (I know. I did it about 3 months ago.)
I gave my kids a lesson on cutting glass since one of them discarded a piece about 2 x 3 feet long. Using a new cutter I scribed it - noting it was REALLY hard to do. Then I showed the tapping from beneath method to propagate the crack to break the two parts in two. It was painfully loud. Hearing protection loud. And nothing seemed to be happening. At this point I decided to maybe not continue this on the kitchen table.
I took it out side to a work bench. It was dark and cold so I left it for another day.
Next day I set it so it was correctly hanging off the side of the bench and with hearing protection tapped it again from beneath. This wasn't getting it and I started to think something was very amiss. I got a hammer. And used that to tap it from beneath. It sounded like I was beating on a steel plate. I actually got very nervous about this whole thing. I decided it was getting just too dangerous. By now I was pretty sure this was tempered glass - especially since I had no idea of its pedigree.
I took it down and set it on its edge between two pieces of plywood that were leaning against a wall. I walked away. As I got about 5 paces away there was a loud BANG! Broken glass had sprayed a distance of about 5 feet out of the plywood opening up the driveway. The glass finally decided to relieve its tempered stress.
It's three times stronger than untempered glass. It also is five times more resistant to temperature shock. This means ANYthing made of tempered glass can weigh about 1/3 as the same thing made from untempered glass and the maker gets to use 2/3s less glass building it. It also is very dang hard to actually break. But using tools, ignorance, and perseverance, you can do it! (I know. I did it about 3 months ago.)
I gave my kids a lesson on cutting glass since one of them discarded a piece about 2 x 3 feet long. Using a new cutter I scribed it - noting it was REALLY hard to do. Then I showed the tapping from beneath method to propagate the crack to break the two parts in two. It was painfully loud. Hearing protection loud. And nothing seemed to be happening. At this point I decided to maybe not continue this on the kitchen table.
I took it out side to a work bench. It was dark and cold so I left it for another day.
Next day I set it so it was correctly hanging off the side of the bench and with hearing protection tapped it again from beneath. This wasn't getting it and I started to think something was very amiss. I got a hammer. And used that to tap it from beneath. It sounded like I was beating on a steel plate. I actually got very nervous about this whole thing. I decided it was getting just too dangerous. By now I was pretty sure this was tempered glass - especially since I had no idea of its pedigree.
I took it down and set it on its edge between two pieces of plywood that were leaning against a wall. I walked away. As I got about 5 paces away there was a loud BANG! Broken glass had sprayed a distance of about 5 feet out of the plywood opening up the driveway. The glass finally decided to relieve its tempered stress.
