Is it possible to cut glass with scissors?

A YouTube video claiming that it's possible to cut glass with scissors by placing the glass underwater has been attracting some skepticism. Geekologie suggests that the guy in the video is swapping out pieces of glass with other pieces of glass as he pretends to cut it.

Hmm. I'm no expert on this subject, but after some quick googling, I'm inclined to believe that it is possible to cut glass with scissors by holding the glass underwater., which appears to be a commercial glass company, addresses the claim on their site (though not with specific reference to the YouTube video). They say that the trick does work, though it doesn't make a very clean cut. They quote from Scientific American to explain why holding the glass under water aids the cutting process:
water causes glass to crack more easily because when a water molecule enters the crack, a reaction occurs in which a silicon-oxygen bond at the crack and an oxygen-hydrogen bond in the water are cleaved, creating two hydroxyl groups attached to silicon. As a result, the length of the crack grows by the size of one bond rupture. The water reaction reduces the energy necessary to break the silicon-oxygen bonds, thus the crack grows faster.
An article by some guy name Paul Umstead, titled "How to cut glass without a diamond cutter," also asserts that the glass-under-water trick works. Umstead sounds like he knows what he's talking about, which is more than I can say. So I'm going to say that it seems to be true that you can cut glass with scissors by holding the glass under water. I would test it out myself, but I don't have a spare pane of glass lying around.


Posted on Fri Apr 13, 2007


Glass itself is a highly viscous liquid, so possibly being immersed in material in a similar state contributes to the mutability of the glass.
Posted by Zoom  on  Fri Apr 13, 2007  at  04:09 PM
Glass is no more liquid than steel or paper. See
Posted by Carl Fink  on  Fri Apr 13, 2007  at  11:09 PM
Um, your link just shows that glass still eventually flows like a liquid, but only much slower than was commonly believed until recently; longer than the universe has existed instead of hundreds of years.

Also... "[D]efinitive proof might require an instruction book written in the Middle Ages advising glaziers to install glass panes with the thick end at the bottom. Now if only such a handbook could be found."
Posted by Zoom  on  Sat Apr 14, 2007  at  09:34 PM
I seem to recall a successful demonstration of this on the UK children's TV programme 'How', probably in the late '70s.
Posted by MrHenderson  on  Mon Apr 16, 2007  at  03:29 AM
I had some glass from an old picture frame so I decided to test it out. I wouldn't call it cutting as much as breaking off and snapping. The scissors didn't give any clean cuts. They would start to go through and chunks of glass would fall off where ever they felt like making a break. I "cut" one side of the glass and decided I would make a short video on trying out the other half. It is possible to take a scissors to glass in water but I wouldn't say you would get perfect clean cuts to do much with it. My cat got a bit curious on what I was doing and decided to grace the left side of the screen with her presence. Anyway, we can see how it went for me here.
Posted by Suki  on  Mon Apr 16, 2007  at  02:19 PM
Para los usuarios con buen nivel de espa
Posted by Francisco J. Moreno  on  Tue Apr 17, 2007  at  04:11 PM
LoL, this was tried...and failed
Posted by gilmo152  on  Wed Apr 18, 2007  at  12:54 AM
About the glass beeing liquid... in Sweden there are churches with glass panes that are thick at the top...

Glass is not liquid in a time span that will make any difference.
Posted by Mr Science  on  Wed Apr 18, 2007  at  04:13 AM
I tried it too and it didn't work. The glass just sort of chipped off, and I couldn't control where it broke. The scissors I used were junky, so maybe a better pair would help.

I was all excited because I thought it would be an easier way to do stained glass windows.
Posted by Justin  on  Fri Apr 20, 2007  at  02:32 PM
Glass will flow if allowed time more than the age of the Universe? I'm guessing just about anything would! And what conditions are we talking about? What kind of pressure is it under, for example? Under enough pressure, rock will flow. Window panes do not sag, I know that.
Posted by Ian  on  Wed Apr 25, 2007  at  11:45 AM
Actually this does work, I did it when I was a kid. The glass doesn't cut very cleanly but, it doesn't shatter either. It's kind of cool. I have no idea why it works though.
Posted by joe  on  Tue May 22, 2007  at  05:45 PM
Doesn't seem much of a mystery to me.

The scissors start a crack that instantly propogates though the sheetw wherever it wants. Glass isn't **cut** so much as it's broken.

A cutter places a scratch on the glass which provides a weakness for the glass to break along.

The "Scientific American" explanation is not likely from the magazine but is just made up by someone who took General Chemistry and knows enough to be dangerous.

Take it from a chemist, it's BS.
Posted by bones  on  Tue Aug 14, 2007  at  05:27 PM
The reason that glass is thicker in windows at the bottom is because of two different reasons. One due to the production of the glass. Back in the good old days of glass production everything was made by actually blowing the glass. IE> I guy with a really log pipe blow out a bubble in a molten lump of glass. Then they spun it out with centrifical force making a large plate. The center of the plate is thicker than the edges. They sawed off the round sides making it the shape they needed but one side was always thicker toward the inside of the plate due to being hand made.

Now the reason it is always on the bottom of is that it is more stable to place a piece of glass that way. Simple now that you know eh?

Gnat of Glass.
Posted by Gnat of Glass  on  Tue Sep 18, 2007  at  09:55 AM
I've actually done this. To make an oval picture glass.
To those who tried and failed I would say that it has to be done in a certian way. Don't just try to snip the scissors blades together quickly as if you were cutting paper. You have to make small controlled motions and kind of "feel" your way through. It helps to stay relaxed and focused and have patience.
The perfection (or imperfection) of the cut is a matter of skill and practice.
Posted by jill  on  Fri May 02, 2008  at  09:19 PM
Glass is an amorphous solid. It does not flow at normal temperatures, ever.

As explained above, it's thicker at the bottom of very old windows panes because the installers weren't idiots! It's easier to install with the thick side down.....
Posted by Peach  on  Wed Sep 24, 2008  at  05:39 PM
dont try with tempered glass. disastrous results
Posted by jokes  on  Wed Jan 07, 2009  at  01:18 PM
Oh my god... Are you guys really fighting over if glass will cut with scissors? Who cares?????? If it does then great if not then oh well!!! Stop being little babies over it.. Ang glass over a period of time will run/sag... Look at old bottles and windows duh.......
Posted by Gary  on  Fri Mar 13, 2009  at  07:49 PM
"Glass itself is a highly viscous liquid, so possibly being immersed in material in a similar state contributes to the mutability of the glass."

No. It is not a liquid because it is thicker at the bottom of old windows, that has to do with how they made the glass.

Please, *please*, stop being retarded.
Posted by P-Dub  on  Sat Sep 26, 2009  at  08:24 PM
You don't know what you are talking about. You say you do, but actually, you seem to understand the quotes you use in explaining the fact that you don't understand the answer you eventually lurch towards (that this is possible) At that point what are you contributing and why ? Christ why bother ?
Posted by max  on  Mon Dec 28, 2009  at  02:50 PM
Yeah, cutting glass underwater with scissors definitely does NOT work! LOL!!!
Posted by Cut Glass  on  Sat Jan 29, 2011  at  04:38 PM
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