Cutting and shaping granite

[wishiwastommy]

Hi all

I am new to the forum (have been reading for the last month or so) and I was just wondering if any of you guys know how to cut and shape (and also polish) granite. I have a small slab (1000x600x20) and I want to make it into a top for a table I am making.

Is it worth just getting a pro to do it? What would that cost. Does anybody know of any in Bris vegas?

Thanks

*mark

[johnc]

You have picked the toughest of stone, marble, sandstone bluestone etc cut easily but granite laughs at most gear. I would imagine the diamond blades floating around will do the job, just add water get a basic blade no point stuffing up an expensive one and see how you go.

To polish you need to get down to a sawn smooth surface and rub back with finer grits until you manage a polish, get in touch with a masonary supplier and they will advise the type of paste and wheel you require, you can possible get one that will fit an angle grinder.

IMHO I would not even think about it, look up granite, stone suppliers specalising in kitchens or monumental work and get them to do it. They have the right gear the cost is usually reasonable and you will get a good job, don't know if you will find one to touch your material but if its a flat slab with an existing polished surface you should be right. A rough old bit of rubbish belongs in land fill it's cheaper to buy a polished piece cut from large stock than polish up a small item.



JohnC

[vsquizz]

Yeah, get a pro to do it. A diamond blade will cut it (slowly) but it can leave a rough cut. My uncle has a polishing machine for small pieces but you are best off approaching a benchtop mob.


Cheers

[wishiwastommy]

thanks guys

I think i will take it to a pro. Don't really want a dodgy job.

Thanks again

*mark

[Stubchain]

Grinding and polishing granite by hand is a long process. You need silica carbide and a finish off with an alumina based polishing compound. Best to get someone with the appropriate machinery. Hand held grinders have a water jet right through the centre, these are usually diamond of varying grades. Funny enough granite is not very difficult to polish once it is smoothed. The harder a substance the easier it is to polish, the hard part is getting it fine enough.

[johnc]

Stubchain is quite right, with granite you actually polish the stone, with something like marble which is relatively easy to polish with a carborundum stone followed by something finer such as a piece of flat sandstone which is capable of breaking off into a soft slury both with water you then apply a polish to give a shine. Fine for indoors but no matter what you do marble lacks the strength to hold a polish outdoors. Before diamond saws granite was cut with huge cross cut saws, nothing like those used in woodwork, these had arches that held a slury of steel shot and putty and gradually worked there way through the stone. Mind you if you are really keen drill a series of holes not through the stone though. fill with water and leave over night, if the temperature drops below freezing the ice will crack the stone along the drill line. Not so good for temperate climates like ours. Thats enough useless information none of this is siutable for the home handyman.