How to cut a glass tabletop - GIF

**tonyfoale** · Dec 29, 2018, 01:23 PM

Originally Posted by jasp93

The question of rapid “healing” is absolute rubbish - a minute or two, an hour or two etc etc etc makes no difference.
Cutting glass is all about a very fine scratch and confidence!
Jim P

Several decades back one of our kids scratched a mirror. We are still waiting for it to heal.

**Frank S** · May 13, 2019, 08:17 AM

My vote would be the next step would be to grind the edge then placed in an oven to soften the glass to allow it to be shaped into a slight dome. I have a clock with a domed shaped glass just about that size. Also the picture frame comment is a good one.
Make a visit to the house of frames and you can find any number of round or oval shaped frames both with flat and domed glass

**CharlesWaugh** · Nov 30, 2018, 01:08 PM

No, it's not rubbish:
https://www.lehigh.edu/imi/teched/Gl...5_Hermanns.pdf

See page 11 of the presentation (keep in mind these are simply powerpoint slides, not the full lecture, so it's just the very highest of the high points)

I remember reading a Scientific American article ages ago about this, but I don't have access to searching and finding that article (paywalled).
The micro-cracks self-heal, and the oil on the wheel gets in the cracks and keeps them open.

But, in everyday real-world life, no big deal.
:-)

**mklotz** · Nov 30, 2018, 01:45 PM

A good deal of the hocus about glass flowing arises from the observation that many cathedral window panels are thicker at the bottom than the top. This seems to indicate gravity-induced "flowing" until you realize that just as many panels are thicker at the top than at the bottom. Then there's the problem of all that ancient Roman glass that, despite sitting around for millenia, still hasn't flowed.

For a more detailed discussion, read what the Corning Museum of Glass has to say about it...

https://www.cmog.org/article/does-glass-flow

That said, my great uncle used to do all the glass work for a major hardware store in Allentown. My Dad and I often visited to watch him work. He frequently spoke of the need to make the break quickly after scoring the glass. I'm inclined to believe that his concern (and that of other glass workers apparently) was genuine but due to some other physical effect than the glass "healing".

**Frank S** · Nov 30, 2018, 02:09 PM

I'm not so sure if it is the self healing or the migration of micro fractures caused by the cutter. A pressure wave is created in the pane of glass when scored this wave needs to get relieved as soon as possible otherwise the micro fractures might create larger fractures.
Not sure if this is the reason but there is a high plausibility IMHO.

**PJs** · Dec 1, 2018, 10:40 AM

I semi apprenticed under a master glass guy over in Berserkly for a year off and on, making Tiffany style (foil wrapped) stained glass which typically is not flat or even thickness and breaking that stuff quickly is imperative. The glass composition itself has a lot to do with it as well as temp control. He made much of the glass we used with techniques that were beyond me at the time. He eventually migrated into making 14-15th century blown glass miniatures and worked in Iran just before all heck broke loose teaching the next generations glass making...got out just under the wire.