Cutting mirrors

[Steve]

Anyone know if it is possible to cut mirrors to size or are they already hardened? Steve

[BigWallop]

If the glass has two or three small dimples on one edge, then the glass has been hardened after being cut to size. If you can't find any small dimples around the edges of the glass, then it should cut easily.

[Andy Dingley]

They're just glass - some of it is tempered for safety, but most isn't.

Same as always, a sharp cutting wheel to score, lubricate with white spirit or paraffin, a good solid straight edge that isn't going to move when you lean on it, and only make a single bold pass with the cutter. Then slip a matchstick under one edge of the score and press down.

Mirrors have a bad reputation for being hard to cut, but it's largely undeserved. Old ones were no different. Modern mirrors are all "bathroom grade" and have a plastic coating over the silvering. This makes them _slightly_ harder to separate, but it's no big deal and doesn't affect the score/snap process. Just use a scalpel to slice any backing that doesn't part.

More than ever, use a piece of old carpet as a cutting mat and be scrupulous for cleanliness. Scratching the coating with a shard of cut glass is a real pain !

You _can_ grind or bevel your own edges by hand, working with a coarse carborundum stone under water. It's a grim job though.

For an easy life, take a cardboard template to a good glazier. If it's a curved edge or you need a ground edge, this is recommended.

[N. Thornton]

why under water, rather than just wetting the stone?

NT

[Andy Dingley]

Water damps vibration and supposedly reduces chipping. If you use a powered glass grinder (a proper one for stained glass) it'll have a water pump and recirculator.

I haven't done enough to know how true this is. Maybe I'll cut out two dozen arched mirrors this week and find out...

[Jon Nicoll]

'when I wer a lad', I read in one of those '1001 science projects for boys' type books that you could cut class underwater with a pair of scissors.

The idea always fascinated me, although I never actually tried it in earnest. I would be interested to learn just how 'likely' this is..

Jon N

[Andy Hall]

The Book of Experiments by Leonard de Vries.

This is a classic of this type and I am pretty sure it has the cutting glass with scissors experiment in it.

Amazon have secondhand copies.

[Andy Dingley]

Thin glass, big scissors, it works. Gilbow tinsnips are probably easier to find in suitable sizes. I used 35mm glass slide mounts for the glass.

Dry the scissors carefully afterwards!

[The Natural Philosopher]

Seems a complicated way to do it. We just used to bunk off and go train spotting...