Cutting granite worktop

[baddiyer]

I'm fitting a kitchen that I took out of someone else's house. I'd really like to be able to use the granite worktops too. They obviously already have finished edges and I'd just need to chop the ends off a few to get everything to fit. Most of the cuts needn't be 100% perfect as think I can hide most of them under the fairly thick granite splash back (or perhaps a bit of trim by the oven etc). I've also bought a sink that fits the existing cut-out.

I was hoping I could do this myself. I have a 115mm angle grinder with a newish diamond blade (happy to buy a new one). I also have an older 1500watt corded circular saw and have seen these blades adapted from cutting discs for angle grinders to fit carpentry type saws https://www.atsdiamondtools.co.uk/product/diamond-blades-to-fit-165mm-x-20mm-plunge-saws/ (I'd have to use a reducer to fit my model). Loads of videos on youtube of people doing this with such tools (including people pointing a dribbling hose at the front of their circular saw, which I find scary personally, athough maybe RCD protection makes this fine?).

Anyone with experience / tips? Or is it a terrible idea? If the latter, any suggestions about what I should rent / buy instead. Pro I mentioned it too wanted in the region of £400, so would probably be happy to pay a couple of hundred for something - perhaps something like this? https://www.screwfix.com/p/evolution-r230dct-230mm-electric-disc-cutter-220-240v/520kr or maybe I’d get more use out of a larger angle grinder (don’t have any experience with one and no idea how straight an edge I could keep with it)

Any thoughts appreciated, thanks

 

[johnny2007]

DO NOT USE A CIRCULAR SAW.

Your 115mm grinder will not be suitable.
A 9inch + grinder with diamond blade should work, however, if I were you I would simply take the worktops to a marble merchant and have it cut there.
For 2 straight cuts they charged me £50 at the beginning of the year.
No mess and perfectly straight.

 

[baddiyer]

Hi @johnny2007 Appreciate your response. There are a number of pieces and they’re still big enough and easy enough to damage that I’d rather avoid having to get them to someone if at all possible (although we moved them once, so I’m not dismissing it out of hand) and it’s going to cost me more than that to get someone to mine.

On the saw idea, I wouldn’t have considered it until I started googling. But people seem to do it (see YouTube and the blades I linked to). I’m not saying you’re wrong, but would like to know what I am / they are missing. The main tip I’ve seen (beyond the hosing, which I wasn’t planning on following, and the need to be prepared for hellish levels of dust) was to do it in 2 or 3 shallower cuts. Would this make any difference or is that no still just as emphatic?

Thanks again

 

[foxhole]

Did many cuts on granite with 4” grinder and tile blade, like a knife thru butter, use a sacrificial timber straight edge on longer cuts .

 

[baddiyer]

Did many cuts on granite with 4” grinder and tile blade, like a knife thru butter, use a sacrificial timber straight edge on longer cuts .

Sounds like that’s at least worth a try before I go out and buy anything. Cheers mate

 

[Notch7]

Hi @johnny2007 Appreciate your response. There are a number of pieces and they’re still big enough and easy enough to damage that I’d rather avoid having to get them to someone if at all possible (although we moved them once, so I’m not dismissing it out of hand) and it’s going to cost me more than that to get someone to mine.

On the saw idea, I wouldn’t have considered it until I started googling. But people seem to do it (see YouTube and the blades I linked to). I’m not saying you’re wrong, but would like to know what I am / they are missing. The main tip I’ve seen (beyond the hosing, which I wasn’t planning on following, and the need to be prepared for hellish levels of dust) was to do it in 2 or 3 shallower cuts. Would this make any difference or is that no still just as emphatic?

Thanks again

I’ve cut construction board and tiles with a diamond blade in a track saw. I’ve not tried granite but it would work.

You need vacuum extraction (a Henry with a new bag would work) or it will ruin the machine and cover you in dust.


The problem you might have is polishing the edge + I guess you need a small chamfer too, not sure how you would do that neatly

 

[johnny2007]

Using the wrong tool with an adapted blade can have disastrous consequences.
I think a member here died when he did that.
By all means, try with the 115mm grinder you have, but it might not cut through.
Failing that, I would rent a large wet grinder, same as the ones they use to cut paving slabs for pavements.
It all depends what material you're cutting: some marbles are a lot softer than others and surely 30mm granite is something you won't be able to cut with 115mm grinder.

 

[baddiyer]

Using the wrong tool with an adapted blade can have disastrous consequences.
I think a member here died when he did that.
By all means, try with the 115mm grinder you have, but it might not cut through.
Failing that, I would rent a large wet grinder, same as the ones they use to cut paving slabs for pavements.
It all depends what material you're cutting: some marbles are a lot softer than others and surely 30mm granite is something you won't be able to cut with 115mm grinder.

Yeah, I hear you on the wrong tool thing. It’s my concern too. To be clear, I wouldn’t dream of modifying the blade myself. It’s only the fact that it’s a reputable (I assume) uk company modifying their own product that makes me think it ought to be ok. I’ve now emailed the company with my specific tool and use and will see what they say… or just try the angle grinder on a spare bit (we have way more than we need) and look into hiring if it’s not up to it or the results are poor

 

[baddiyer]

I’ve cut construction board and tiles with a diamond blade in a track saw. I’ve not tried granite but it would work.

You need vacuum extraction (a Henry with a new bag would work) or it will ruin the machine and cover you in dust.


The problem you might have is polishing the edge + I guess you need a small chamfer too, not sure how you would do that neatly

Thanks for the tips. I’ve messaged the company who make the blade for a little more specific advice too. Cheers

 

[opps]

You need vacuum extraction (a Henry with a new bag would work) or it will ruin the machine and cover you in dust.

Silicosis... the new asbestos. Best to wet cut it.

Deadly lung disease in UK kitchen worktop workers is avoidable - British Occupational Hygiene Society (BOHS)

Silicosis, an incurable lung disease, has been known about for thousands of years. However, in recent years younger workers are being reported as being severely affected when working with the cutting and finishing of engineered stone worktops, widely used for kitchen refurbishment.* The disease...

www.bohs.org

 

[mrrusty]

I've never used one, but reputable companies sell diamond blades for track saws to cut granite https://www.atsdiamondtools.co.uk/product/diamond-blades-to-fit-165mm-x-20mm-plunge-saws/

 

[Laurieo]

Hire a petrol angle grinder for slabs with a diamond blade . Clamp a bit of timber to worktop where you want cut as a guide .
Use plenty of water and do out side wearing mask and glasses.
I just done similar to what you are doing and it worked out fine cost about £35 for the week end .