Could a glass smith restore a cracked mirror?

Question

I want to know if a glass smith, or anyone, or anything, can get rid of cracks in a mirror. I'd imagine no, but.. even though I don't know much about the subject, it seems like they could just melt parts of the glass so it bonds with itself again, then cool it off so it resolidifies as one piece with no cracks.. am I missing a key obstacle here or what? thanks.

Answer 1

No, it can't be done. The problem is that to keep from cracking the glass while heating, it has to be heated very evenly all the way across. In theory, this could be done in a kiln over a few hours. Then, in theory, the heated sheet could be melted with a torch by someone using one of those silver heat suits.
But the heating would destroy the paint and the aluminum or silver "silvering" on the back of the glass and the welding would produce a distorted surface.
Much much easier and cheaper to start with new glass and recycle the old or keep the old cracked glass if it is distinctively carved, etc.

Answer 2

I don't think so. Mirrors are first a piece of float glass that is made by melting glass in a puddle of molten tin inside of a kiln. The glass is then aluminized on the rear inside of a vacuum chamber. I've done a little work with glass, and I can't imagine doing a welded repair,which would then have to be ground and polished with a series of grits and then re-aluminized. I'm pretty sure it would be much cheaper to replace it, no matter how special a mirror it was. Sorry.

BW,
GH

Answer 3

Yes you are missing what glass is about. There is no practical way to melt it into a sheet of glass and then resilver the back to become a mirror again.

It is broken just like Humpty Dumpty's egg and it can't be put together again.

Answer 4

It could be done but the price would be very high. More so then buying a new mirror. It would only be worth it in the case of something that is one of a kind and has to be restored without replacing.