Glass, double strength - Cutting Help

[Matt]

Go back to the glass shop.... but DUDE. THIS TIME BRING SOME WEED.

[Charles Spitzer]

double strength glass is 1/8". single strength is about 2/3s that.

you have 1/4". it's harder to cut than double strength.

you might try a stained glass store or anyone you know who does that. they'd probably do it for free but not guarantee that it won't break badly.

if you want to try it yourself, it's always easier to cut something in half than a sliver off a piece. if you're attempting to do the latter, then i'd suggest having someone else do it.

use a $2 carbide wheel glass cutter from the hardware store. score it in a straight line, don't go back and rescore skips, don't retrace the line. you should hear a skritch when scoring correctly. get some window glass and practice first. put a pencil or dowel down under the scored line. press down from both sides firmly. it will break, but take a good deal of pressure. if you're lucky it will break on the line. wear gloves and eye protection.

there are tools to do this safer and easier, but they're more expensive than what you've already been quoted.

a tile cutter won't do this wide a cut.

[Charles Spitzer]

you've seen and tried to cut it?

it may not be. there's no rule that it has to be.

[Charles Spitzer]

well, 1/8" is even easier than 1/4".

it's all technique, and practice does make it easier. if you have problems breaking long pieces, do it more gently at one end of the score, then go to the other end and break from there.

running pliers would help a lot, if you have lots of these cuts.

you can also snap scores over the edge of a table, if you're daring enough.

regards, charlie

[Bo Williams]

[...]

I've never gotten the hang of one of those. There's a technique to it that I can't quite get. I always think my scores are fine, but when I go to separate it I only break it on the line about two-thirds of the time, which is of course an unacceptably high failure rate. :)

My father-in-law does it as easily as marking on lumber with a carpenter's pencil.

Definitely practice as much as you can before attempting your real cuts. Or, just have the glass shop you talked to cut it. Don't think it's a "ripoff" just because you got the glass cheap. How much will it matter that the glass was cheap if you break it all trying to do this yourself?

[...]

[Charles Spitzer]

no, it doesn't have to be lubricated. i haven't used any oil for years in my cutters. you don't see any cutters in home depot lubricated, and all the glass shops i've been in don't use any lubrication.

glass doesn't heal. old wive's tale.

old glass isn't harder to cut then new glass. it probably isn't possible that a stereo cabinet have plate glass, which would be different to cut, than regular float glass.

typically you want about 5-6 lbs of hand pressure to cut glass, no matter it's type or age.

glass is an amorphous solid.

[Charles Spitzer]

you can tell if it's polarized. take 2 pairs of sunglasses. take the glass outside in the sunlight. put one behind the glass, one in front of the glass. look through the sandwich. if you see a pattern in the glass, it's tempered.

[Jon Dogin]

Hi,

I'm hoping that someone can give me some suggestions for cutting scrap double strength glass. I picked up a few pieces from the local junkyard. They look to be pieces from a stereo cabinet - about 48"x12" and almost a quarter of an inch thick. I'm trying to cut the pieces to size so that I can use them as tops for some fish tanks. Mainly I need to do long cuts to split them in half. I was hoping to get this done at the local hardware store, but was told that the glass that I have is double strength and that I'd have to go to a glass shop. The glass shops are charging about $6/cut - that's more than I paid for the individual pieces of glass. I had one person reccomend that I use a tile cutter for this job. Anyone have experience using a tile cutter to cut double strength glass or have a better/cheaper method? Thanks in advance for any help.

J.

[Leonardo]

It requires more pressure to separate but not really anymore pressure to score. It's all float glass... 3/16 and up is called 'plate' glass

Any glass person with half a brain will not guarantee that a cut will be successful :-)

I think it is best described as the sound like slowly tearing a sheet of paper

No, you don't HAVE to lubricate, it's just a much better way to do it.

you don't see any cutters in home depot lubricated, and all the

Commercial glaziers most often use the lub on the intended score line, not on the cutter. Thus, the possibility of your confusion.

Sorry sir, not true. The older the score, the less likely the glass will separate on the line. I don't know the science but I have often tried breaking off pieces on old score lines will little success.

If it is NOS, no, but usually folks are trying to recut old glass that has been exposed to the elements and it will have pitting or etching caused by pollutants that can effect the continuity of the score line.

If that's the case, try and figure out which side faced in and score on that one.

it probably isn't possible

Most unlikely

which would be different to cut,

Again, the score pressure would be the same. It's a misconception that the thicker the glass the more pressure you need to apply to the score line. Since there is no grain 'cutting' glass is really a controlled break along the path of least resistance.

Lenny

[3rd eye]

It's tempered. You're not going to cut it. Fugetabout it.

[Jon Dogin]

Correction - I made an error. It is 1/8 inch glass and not 1/4 inch. I may end up going back to the glass shop, but if I can take the pieces back to the junkyard and swap them for something thinner, that might be the best way to go. Thanks for trying to help.

[Joseph Meehan]

Additional note here. Make sure the wheel is lubricated and turns freely and make sure the glass where you are going to cut it has been carefully cleaned. Don't delay between the time you make the scratch and when you break it. The longer you weight the less chance you will have to have it work. Glass heals itself so after a few minutes the scratch is not as weak as it first was.

Additional additional note: old glass is much more difficult to cut than new glass. Remember that glass in not really solid, but rather sort of a hard liquid.

[Mike Cahill]

How about some advice from an actual glass cutter ?

Lubricate EVERY cut, we use a special oil for this, but in a pinch at home i use 3 in 1 oil. You do not want a "hot" score. Yes, after about 20 minutes a score will NOT run, or break because the score has healed. Slow, steady pressure on the score, and don't pause or stop. Wear gloves and eye protection. Run the score either using the pencil method described earlier, or grab the glass each side the score with thumb and fingers and pry up.

6mm (1/4") is no easier or harder to cut than 3mm once you know how to score it. Cutting machines use varying pressures when scoring.

BEWARE, if you got these pieces fo glass out of a stereo cabinet (regardless of the thickness) they may be tempered and when you score the glass it will go boom !!!

Bottom line, go to damn glass shop and some pieces cut to size, it's not that expensive.

Mike

[JerseyMike]

glass from a stereo cabinet is probably tempered safety glass and you will not be able to cut it. since it is decorative glass, there probably isn't a safety stamp on it, but more than likely it is tempered. hit it w/ a hammer and see if it breaks into a thousand diamond like pieces, if it only breaks into large pieces then you'll know it wasn't tempered....just kidding w/ ya. since you're not sure of how to cut it, bring it back to the glass shop and ask them, but they'll probably tell you the same thing. the only other tip i can give you is, if there are small *dimples* anywhere along the edges, this is a sign that the glass has been tempered,but w/out seeing that stamp it's hit or miss you won't know until it is scored and you try to run the cut.

mike..........

[3rd eye]

No. obviously not.

If it did indeed come from a stereo cabinet I'll bet you lunch it is tempered.

>

[JerseyMike]

a real glazier will lube almost every cut, unless he is using a self-lubing cutter or is if he is only making one or two quick cuts. it's important to keep the wheel and the cut cool to ensure a good clean break, one thing you don't want is a hot cut.

mike.........

[toller]

Yeh, I was taught in high school that glass is an extremely viscous fluid; just look at old windows. Turns not simply not true. Glass is just a plain old solid. Old windows don't flow; they were uneven to start with. Half of what everyone knows is not true. Sadly, it is hard to be sure which half.

But getting back to the poster's question. If you paid less than $6 for the glass, then buy a $2 glass cutter and try it. The worst that can happen is that it doesn't work.

[Jon Dogin]

Well, that was an interesting exchange :-) At this point, I'll probably try to cut one of the pieces myself. As has already been noted, if it doesn't work, I'm only out about $3.50 - what I paid for the glass. If it does work, I just saved myself $6.00. Actually, if I can do this repeatedly - which I'll have to given that I need to make an average of two cuts per piece to get it to the size/shape I want, then I'll be saving a whole lot more. Thanks.

[Charles Spitzer]

i guess i'm not an actual glass cutter, only have 20 years in the business of doing thousands of feet of stained glass.

haven't used oil in years. no difference. there are cutters designed for no oil, specifically diamond, but there are some carbide cutters also.

really? i have some scored glass that still shows the score. 10-15 years old. they aren't healed. still break well too.

it takes significantly more pressure to start the run the thicker the glass is. it doesn't take more pressure when scoring though. it takes a LOT of pressure to run 3/4" glass, as i recently found out.

[JerseyMike]

there is a big difference between making long consistant cuts involved in cutting window glass and plate glass and that of stained glass. a good glazier will always use a lube such as kerosene or mineral spirits or even a light weight oil like WD40 if necessary. a hot cut and a new cutter can ruin a good piece of glass if used wrong. when cutting plate glass you would want to use an older cutter w/ that has been *dulled* a bit and on a piece of SSB or DSB a newer cutter that doesn't need much pressure to make the cut since you can actually break the glass if you push down too hard on on single or double strenght glass . if a cut is too hot it will *pop* little rice like pieces along the cut and make running it very difficult and could make the break unclean and rough.

mike..........