Cutting Granite

[Edward P. Surowiec]

I cut a kitchen sink "cut out" in a six foot granite counter top. I was able to do the work out doors. First attempt was with a $40 diamond Rotozip bit, it took forever just to bore through the 1" granite. I switched to a 6" diamond tile cutting blade and my cut-off saw for the long straight cuts and completed the rounded corners with a 2" diamond blade for RotoZip. As everyone above has said Dust , Dust , Dust is a big problem. I wore a mask, glasses, and worked in the rain and the dust was very bad.

[Mike OMelia]

Everybody keeps saying skilsaw. In the South, we say coke for coke & sprite & etc. So, does this mean any capable circular saw?

Mike

[Ron Fairbanks]

Hi guys and gals, just coming off 15 years in the ceramic and granite tile market moving into the engraving market. My experiance with granite cutting shows this to be the safest and fastest way I've seen. I'm assuming that the sink cut out or faucet cut out needs to be modified. This is what our granite install guys would do. For faucets they would find the largest diamond holesaw they had and do this. Lay a couple of grout sponges soaked in water around the hole or spot to cut the hole. Then they would put a piece of plywood with a hole in it larger then what they needed to drill over the sponges. They would angle the holesaw to start the cut and then plunge down while pressing on the plywood. This would squish the sponges and water would come out cooling the saw and capturing the dust. Keep in mind that as the hole is drilled the water will drip to the inside so plenty of rags were placed there to catch the run off.
Another thing to think about is when you drip coolant on a cutting tool you risk thermal fracture but with a bath will not. Think of pouring hot water on your frozen windshield it will crack everytime. For making a sink cutout larger they used the same process. Use some soaking wet sponges and a straight piece of wood along with your diamond blade saw. Don't let the water get to your power drill or saw unless it is designed for wet use. My two cents, good luck.

[Maurice Ungaro]

So, does this mean any capable circular saw?

Mike

In a word, yes.

[Rob Hermann]

I'll preface this with I have never worked with granite at all but, I have drilled glass which I suspect is similar. When we do holes in glass we use a diamond bit and build a dam around the hole with modelers clay and then pour water into the hole. An assistant can keep pouring if necc and then when you get through you can wipe up the mess easily and no dust at all in the air. It keeps the bit cool and the dust down. Good luck with your project.

[Victor Robinson]

I'll need to trim a granite slab in a bit too and was planning on using the Skil (circ) saw method. So this is very timely - thanks Mike for posting the question.

But what I'm not sure about is to have any water in the equation or not? Water...electric saw not meant for wet use...

[Mike OMelia]

Right. A 120v circular saw is NOT a wet saw. This might be a job for an air saw (and an excuse to get one!)

Mike

[Glen Butler]

I have used power tools that were drenched while while standing in a pool of salt water on a concrete floor with nothing more than a tingle to the finger. No breaker trips no GFI. You will be fine, just get to it.

[Tom Godley]

I had to shorten a granite top for my kitchen after a design change -- they cut the 1.25 inch top with a worm drive saw and a diamond blade. This was a straight cut, they did it outside using a straight edge and a second guy was holding a air gun connected to a compressor to keep the cut clean and keep any buildup from moving the saw. Lots of dust!!

The problem with extending a cutout is getting the cut started on the long side!

[Randy Klein]

I would get a quote from a granite installer to see how much a simple cut would cost you.

[Sam Layton]

Mike, cutting granite is not hard. I cut and installed the granite in my small bathroom, c-photo. After I built the vanity I got an est on the granite. The place wanted $750.00 to fabricate the granite and I had to install. That included $100.00 to cut out for the sink. I found a prefabbed slab 2' X 8' for $280.00. I needed about 21" X 49".

I purchased two diamond blades, one for my skill saw and a 4" blade for my angle grinder. I cut the slab outside with the skill saw. I installed the granite and cut the sink hole inside with my 4" angle grinder. I used my shop vac to catch the dust. It did a good job.

I like Rick's idea with the wet sponge. A 4" diamond blade on an angle grinder is all you need. Just make several passes. A good diamond blade cuts really well.

Sam