Granite question

Another question this time related to granite. I am keen to get hold of a piece for sharpening on.

Well while at the HH Restore it store the other day i came across a two pieces of granite that were from the same top which had cracked in half.

I negotiated the one piece down in price but then i had second thoughts and decide no hurry they been there more than 6 month already and i wanted to check with people here first.

So my question is given this top broke in half (it was a long one) if i bought this peace of granite about 2x2 and a bit more on the broken edge, do you think i would have it shatter and crack on me when i use a grinder to cut the jaggered edge straight to be able to use it.?

Have any of you had this experience before?


My concern is buying it and having the whole thing decide to cut loose on me when i trim the edge something like tempered glass does.

Might sound like a stupid question given its rock but hey i aint taking chances this is what made me negotiate its price down.

How would you cut it?

I have a small diamond blade for my hand grinder and this is what i was gonna use along with some water to keep dust down and things clear and cool.

All advice and comments welcome.

As you know Rob I just did granite tops for my kitchen. I had no problems cutting the granite tiles on my cheap $88 tile saw from home depot. I could reliably cut 1" wide pieces no problem. The top could of cracked because of a vein in the granite and not lifting it without twisting it.

Go ahead and use the angle grinder with the diamond blade. Take your time and if you want to use water to keep it cool while cutting use a sponge to apply the water. You could even set the sponge up against the blade while it cuts to help keep it cool. One more thing I also did to prevent cracking was to make a cut all the way thru the top on the granite on the edges about 1/2" to 1" in from the edge to keep it from cracking off when I finished the thru cut.

I cut a bunch of flagstone using a diamond blade in my worm drive circular saw (Jim Delaney gave me that tip) and it worked like a dream.

I would think with a straightedge clamped on the granite, you could get a very nice cut that way...

I've never done it, but heard of and seen it done on tv with a 4.5" angle grinder and a diamond blade. Wear a respirator or a dust mask. From what I've heard the rock dust is hazardous to your health on a dry cut tile/granite/stone etc.

I have used the concrete blades from the borg, The black one in a circular saw to cut stone. They are cheap and when your done ya can throw it away.

Brent Dowell said:

I cut a bunch of flagstone using a diamond blade in my worm drive circular saw (Jim Delaney gave me that tip) and it worked like a dream.

I would think with a straightedge clamped on the granite, you could get a very nice cut that way...

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Yep! Just do it that way. It'll work just fine.

Control may (or may not) be a problem with an angle grinder. If the blade gets cocked off to the side either it could catch, or the granite could break.

rob, did you hear about the stone that was taken advantage of by all his friends, and then ignored?

he was taken for granite....

Jim DeLaney said:

Yep! Just do it that way. It'll work just fine.

Control may (or may not) be a problem with an angle grinder. If the blade gets cocked off to the side either it could catch, or the granite could break.

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The cut edges with a saw are darn near polished as well, and straight as an arrow... Just make sure to do it way far away from the house and wear a really good dust mask.

All that has been said is true and feasible. But before that and before buying it, I would put it on an edge and knock on it at several points, with my knucles or with small cobblestone.

If it sounds clear then the slat is fine, if the sound is muffled more like "thud" "thud" it means that it has a hidden crack. The same procedure can be used for checking pottery or clay flower pots, the should ring like a bell.

I would use this.
It's what the granite top guys use to cut it with.
One of them at some point in time decided that I would be much better off with this than he was so he left it behind for me.
Oh I should add that I love it when people decide to abandon their tools on my job.