Cutting granite with a circular saw

[Origin Unknown]

Picked up the MIL's new fireplace surround and hearth this evening. Offered up the granite back panel and it's around 2" too narrow so needs widening.

A bit of googling suggests using a diamond tipped wet cut blade in a circular saw should be capable of making the cuts. Any top tips from those that have done this?

I assume the key will be taking it slowly, ensure the slab is well supported and plenty of water. Gaffer tape along the cut to support the cut and to stop chipping and a guide timber for a straight cut.

Should I looked to clamp a timber right up close the the blade on the good edge to further stop it chipping?

[IanMorewood]

For circular saw read angle grinder and its doable. Wear appropriate protective equipment and keep the cut very wet.

[Origin Unknown]

Interesting, the problem I have with using an angle grinder is achieving a straight cut. Have a look here

[B17NNS]

Circular saw for granite?

Grinder with a diamond blade would do it. Better if you can keep the piece/blade wet.

[Origin Unknown]

I wasn't so sure but have a look at the link in my previous post. I'm assuming decent wattage Circular saw would be required, think mine is 1500W so should be up to it? Like I said previous, I like the idea of using a circular saw over a grinder for control more than anything.

[Simpo Two]

Origin Unknown said:

Offered up the granite back panel and it's around 2" too narrow so needs widening.

I like the way you can make something wider by cutting it

[Origin Unknown]

Don't tell anyone, but as a result of many years of cutting too much off, I've now perfected a way of cutting more on

I'm talking abut the opening of course!

[Griff Boy]

I've only ever cut granite with a grinder, never even though about a circular saw!

If it's just a simple rework of a piece to fit, and your not confident with a grinder, then maybe worth just taking the piece to your local granite / fireplace / headstone place and paying them to cut it for you, maybe easier than trying to source a specialist blade for a rip snorter that may or may not work..

[rhinochopig]

Griff Boy said:

I've only ever cut granite with a grinder, never even though about a circular saw!

If it's just a simple rework of a piece to fit, and your not confident with a grinder, then maybe worth just taking the piece to your local granite / fireplace / headstone place and paying them to cut it for you, maybe easier than trying to source a specialist blade for a rip snorter that may or may not work..

A thousand times this. Why take the risk?

[blueST]

I've cut concrete with a diamond blade in a regular (Rage) circular saw with no problem. Leaves a lovely finish and a straight edge. I didn't use water either for fear of getting electrocuted. I was cutting flags that had already been laid on a concrete base. The amount of dust was unspeakable though.

Having said all that, how much tougher than concrete granite is, I don't know. I think you should have a go, even if you ruin the job it'll bee recorded here as a warning to all us DIY have a go heroes!

[993AL]

With a G50 diamond blade, this will cut it http://www.exakt.biz/dc270.html

It's a dry cut but you must use a vacuum with it.

[hairyben]

I'd use a continuous edged or tile/granite specific blade.

If you're looking to cut off two inches, I'd do a practise cut at 1" on the waste side so if it all goes tits the slab isn't ruined.

Insulation tape in a contrasting colour can be a good way of marking a cut line.

[Busterbulldog]

I have cut a few of these over the years..9 inch angle grinder with a diamond blade. Cut it on a flat surface eg sheet of ply.If the cut edge is not hidden by the fire just get it cut professionally it wont cost a lot.

[pacman1]

Slightly off topic, but I hope u guys wear an appropriate mask cutting stone.
Soft stone, eg limestone ain't so bad, but hardstone dust is really not good for the lungs, it's as bad as coal dust.

[V8RX7]

Circular saw, wall chaser, angle grinder - really doesn't make any difference.

G clamp a straight edge to the stone ensures you get a straight edge regardless.

A good blade and taking your time PLUS a practise cut first, ensures a good result.

However as mentioned for a one off I'd pop to the nearest stone place and get them to cut it - would cost less than the blade.

[hairyben]

V8RX7 said:

Circular saw, wall chaser, angle grinder - really doesn't make any difference.

It kind of does, they're 3 different specific tools.

[Origin Unknown]

Some good advice in here, based on someone else mentioning it, just remembered that I already own a twin blade wall chaser (I try not to think about this tool as there is nothing enjoyable about using it).

Whilst I am tempted to find a DIY solution and post back the results, I will initially see what someone will charge to do the cut for me. I have enough work with this fireplace without creating more for myself.

[V8RX7]

hairyben said:

V8RX7 said:

Circular saw, wall chaser, angle grinder - really doesn't make any difference.

It kind of does, they're 3 different specific tools.

Really, in this case, in what way does it matter ?

Which is the specific tool for the job and why ?

[Wozy68]

I'm a wood machinist by trade and have used many many woodworking machines, some are exceptionally dangerous to use and I've used them all.

However I would be scared stless using a portable circular saw to cut granite, whatever blade was installed. I have no idea if it works or not. (I build and install quite a few kitchens and never seen a granite installer use one on site) But I'd hate to think how many fingers/hands/arms I could lose if it doesn't. I would NOT try it.

Personally I'd take it to a granite company and play safe.

Edited by Wozy68 on Sunday 19th October 21:59

[Muncher]

Wozy68 said:

I'm a wood machinist by trade and have used many many woodworking machines, some are exceptionally dangerous to use and I've used them all.

However I would be scared stless using a portable circular saw to cut granite, whatever blade was installed. I have no idea if it works or not. (I build and install quite a few kitchens and never seen a granite installer use one on site) But I'd hate to think how many fingers/hands/arms I could lose if it doesn't. I would NOT try it.

Personally I'd take it to a granite company and play safe.

Edited by Wozy68 on Sunday 19th October 21:59

This x10000. It's just a recipe for disaster.