Tools for Cutting & Polishing Granite
Granite is an extremely hard stone and isn't easily cut. You'll probably need some power tools, whether you're aiming to create sculpture or cut an appliance port in a granite counter top. Granite's hardness, however, isn't the only factor to consider before you get started.
Granite contains silica, which is dangerous if inhaled, so there's some special safety equipment involved in the process as well. Whatever your goal, be prepared to put in hard work and sweat when dealing with this stone. Here are some tools that will help you out.
This is an important consideration with granite. Flying and falling stone debris is dangerous, and working with the power tools you'll need is noisy and hard on the hands. You'll want to cover up with a good pair of coveralls and wear eye protection, ear protection and shock-resistant gloves. It's also advisable to wear a respirator when working with any stone, and you'll also want a good pair of steel-toed work boots.
For this job you'll probably want to use two different grinders: one with a larger blade for roughing out the shape, and one with a smaller blade for closer work and for getting debris out of corners. There are saws specifically made for stone, but they're more expensive than a basic industrial grinder. Look into your options and do some research to find out which saw will be right for you and will be most efficient for the amount of time you'll be working. It's best to use a water-cooled saw system when working with granite, because it helps keep down the dust and silica.
Generally speaking, a nine-inch blade works well for roughing things out and a five-inch blade is better for detail work. Nine-inch blades are usually rated for a maximum of 6000 RPMs; don't exceed that maximum. Different saw blades are meant for different materials, so buy a blade that's meant to be used on granite or marble and is diamond impregnated. It's also important to keep an eye on the wear to the blade. If your saw keeps jamming for no reason, it probably means the blade is worn out; toss it and buy a new one.
Hammer and Chisel
It's important to use tools that are of high quality when dealing with granite, because it will break even carbide-tipped chisels. Use a high-quality steel hammer, around three pounds, for removing large chunks of stone. You'll also want high-quality steel in your chisels. Twelve-inch chisels are good for rough work, and an 18-inch chisel can reach into deeper areas to remove excess stone from crevices. A protective handle on your chisel will save you a lot of pain should you miss your mark with the hammer.
To polish your granite, you'll need a pneumatic polisher with a center water feed, which will help keep dust down and the polisher cool. Some of these come with heads that will accept different pads of different grits; make sure the polisher you use has pads containing diamonds, and you'll need a very fine (3,000) grit in order to polish granite.