Cutting rough glass

Interesting question.

My first thought would be to find someone with a waterjet to cut the slabs for you. "Maybe" you could cut it with a diamond bladed tile saw, depending on the thickness of the glass.

But, this glass is (probably) "pyrex", and I don't know if it could even be cut without shattering. It might have to be re-annealed first? Some of the glass blowers around here might know about that.

If you can get it cut, then you'll have to have it polished, as the saw blade or water jet will leave a surface that looks like the glass has been sandblasted with coarse sand. And then comes the question of etching it. With what, sandblasting, grinding, or acid?

It's the kind of job that somebody with a lapidary (stone-working) workshop could probably undertake. A water-cooled, diamond 'slab-saw' (as used for cutting slabs of stone) would do it - and would allow the glass to be clamped to ensure that the slabs are parallel.

You'd probably need to get the slabs of glass polished afterwards (lapidary job again, successively finer grades of abrasive followed by a polish) before doing the etching.

As to wastage - the saw will take out a slot of maybe 1/8" inch, possibly a little thicker....

Hope this helps ? Adrian

Do I understand right that you want to cut the curved fresnell pieces radially, to get say ½" slices withthe three polished sides intact. Interesting job. How thick are the fresnedd segments. A tile saw may reach 1½"deep lapidary saws a little deeper. Large blades are thick to prevent vibration. What you need is to get together

1. A glass artist with that kind of experience of cold working with wet belt sanders and plishing planes.
2. A gravestone maker with proper saws. The etching then is easily found.

-lauri

a normal 10" tile saw will cut these ok. you can cut up to about 4" thick. it won't be polished, which will take normal glass polishing techniques. someone with a flat lap or vibrolap could do that.

Thanks for the advice and I think I'll go with the 1/4" thick and get it polished. These are like big rough pebbles mostly and came from the lens being smashed on the rocks when being replaced years ago. I keep finding lumps and have given a good few away to visitors who have an interest in lighthouses or this location. Just thought if not too expensive it would be nice to be able to give them a piece engraved by a local artist. Thanks again to all for the advice and I am taking some down on holiday with me in a few weeks and will try to locates a firm in the Yorkshire/lancashir/Cheshire area that can do the job.

Mike

Ah - you didn't say you were in the UK !

Have a word with Andy at

bloke, did some cutting / polishing for a neighbour of mine whenI lived back in the UK.I've only got a small lap saw at the moment, so can't help youmyself... sorry...

Hope this helps Adrian

That looks fine and would fit in with a day or so going from the North Yorkshire Moors to the Dales and then on to the Lake District.

Tahnks - Mick

No problem - as I say, he did a good job for me a few years ago on some uncut agate geodes that my neighbour brought back from somewhere in Africa. They came back nicely cut in half and polished

Hope it works for you Adrian