How do I cut mirror?

[Craig D Peltier]

I have some 3/16th large mirror pieces I took down from my walls in master bath. There like 5 feet x 5 feet and one 4x8 and another one 5x5.

Im aware of the glass score tool that you hold a straightedge on but havent used one for years. Do I do mirror the same? Any techniques appreciated.
Do I score from back since I need to be careful to cut through the reflective material?

[Ray Schwalb]

All you should need is what you suspect, a solid flat surface, a $3 (maybe now $5) glass cutter and a straightedge. One firm score (and only one) on the front, and you should be able to snap it right off. I used to work in a glass shop, and though we had fancier tools, that was the technique.

[Frank Drew]

I've cut glass from time to time over the years but I don't think I've ever cut mirror. With pieces that big, I'd at least think about bringing them to a glass shop for cutting, if possible.

[Bill Spievak]

Thicker glass requires a different angle on the cutter head. Using a glass cutter designed for single or double strength glass on thicker glass will result in unhappiness.

[Andrew Nemeth]

In addition to the previous comments:
use a sharp cutter and dip it in a lubricant before every score (kerosene works well). After scoring ONCE, slide the score line to just passed the edge of your table and firmly and evenly snap the glass. Do not hesitate when attempting to snap or you may get a run away from your score. Cut from the glass from the smoothest side, in this case the side opposite the reflective coating. If you are having trouble snapping a long cut, try lightly clamping (we are talking spring clamp lightly) a board to top of the scrap side before snapping to even out the pressure being applied.

Good luck,
Andrew

[Brendan Plavis]

I would try a diamond blade on a bandsaw, I hear thats whats usually used for cutting glass... Mirror is glass, just polished with mercury(the enviromentalists might have them using something else now..)

But they arent as cheap as a scoring knife(about 100:1) although, you might get straighter cuts .... I did the score and snap method with a piece of polycarb, lets just say thankgod it went in the trash, it was not the cleanest of cuts... and it was a pain, since it needed to be scored about 8 times before it would snap, and this was on 1/8in stuff... I would be cautious scoring and snapping, since it might lead to sutures....

[Frank Drew]

Cutting a sheet of glass that's 5'x5' or 4'x8' on a band saw would be fun.

Not.

[Phil Phelps]

I would try a diamond blade on a bandsaw, I hear thats whats usually used for cutting glass... Mirror is glass, just polished with mercury(the enviromentalists might have them using something else now..)


But they arent as cheap as a scoring knife(about 100:1) although, you might get straighter cuts .... I did the score and snap method with a piece of polycarb, lets just say thankgod it went in the trash, it was not the cleanest of cuts... and it was a pain, since it needed to be scored about 8 times before it would snap, and this was on 1/8in stuff... I would be cautious scoring and snapping, since it might lead to sutures....

NO. Never cut glass with a band saw or any saw you use for wood.

[Craig D Peltier]

Cutting a sheet of glass that's 5'x5' or 4'x8' on a band saw would be fun.

Not.

Very true. It must weigh 75lbs. I wouldnt even think of trying a bandsaw or skill saw etc.

[Richard McComas]

Don't know much about cutting glass but I have read that the older the glass the harder it is to cut. How old are your mirrors?

[Glen Butler]

If you score it, make sure you score it good and plenty the first time. It doesn't take a second pass with the scoring knife very well.

[Tony Bilello]

.....a solid flat surface, a glass cutter and a straightedge. One firm score (and only one) on the front, and you should be able to snap it right off. I used to work in a glass shop.

+1 for me. Although I never worked in a glass shop, I have cut quite a bit of glass.
A mirror is nothing more than a piece of glass with a 'silvered' backing.

[Craig D Peltier]

Don't know much about cutting glass but I have read that the older the glass the harder it is to cut. How old are your mirrors?

20 years or less.

[Myk Rian]

I would try a diamond blade on a bandsaw, I hear thats whats usually used for cutting glass...

Whoever told you that is dangerous to be around.
You cut glass with a scoring wheel, then snap it off.
The older the glass is, the more brittle it gets.

[Steve Leverich]

Also - if by some rare chance your mirrors are tempered instead of float plate or safety plate glass, you'll know the second you try to cut them - they'll shatter into little tiny "bb's".

I'm not sure if anyone still makes tempered glass mirrors, but just something to watch out for... Steve