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Cutting and drilling slate

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Richard_C

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I have a couple of pieces of slate bought years ago from the odds and sods bin of a slate mine shop. Might be useful one day kind of purchase.
They are c. 15 cm wide by 2cm thick and 100 long, square edged and well finished.

I now have a use for them as plinths for wooden sculptures but would need to cut to shorter lengths and drill through.

First thought is my small angle grinder to cut, and masonry bit to drill, maybe lubricated by running water.

Any thoughts or experiences welcome. Not something I have done before.
 

Trevanion

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Depends on the hardness of the slate, the slate we have around here you could drill very nice holes in it without the hammering action on the drill and with a regular jobber bit with the cutting edges dulled slightly to a neutral rake with a stone, the absolute best one I imagine would be a tile drill bit rather than a masonry or jobber bit. Should cut very easily too with pretty much any kind of grinding wheel but a diamond one would be best.
 

Brandlin

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I've had success drilling slate with a tile drill rather than a masonry drill. Not tried sawing though.
 

Rorschach

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A good hacksaw will usually cut slate fine and regular drill bits also work well.

Better though is a diamond drill and a diamond tile saw.

You can sand and polish slate using wet and dry paper.
 

TFrench

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I did our bathroom last year and used a bit of slate that had been in Dad's garden for ever as the countertop. I used a diamond wheel in the angle grinder to trim it to fit, worked a charm. Also used a normal HSS holesaw to cut out for the sink and tap as I didn't fancy buying a diamond saw that big for one job. It burnt it out but it managed two holes through 20mm slate.
 

Lons

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I've cut and drilled a fair bit in my time, various thickness from 30mm down to roof slates thick.
You should be able to drill using ordinary masonary bit but as said not hammer, be careful as you break through the underside as it can flake off. I've never used water when drilling just withdraw the bit and vacuum out the dust as you go. Anything over about 6mm dia I'd drill in stages increasing drill dia.

You can cut with a grinder and thin diamond disk, they're cheap as chips and any will do as slate is soft enough but loads of dust. I prefer to cut however using my wet cut tile saw which gives a nice clean cut.
 

Richard_C

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Thanks all, useful and encouraging information. Looks like it won't be as hard (in every sense) as I thought it might be. I will wait for a day when I can work outdoors to avoid dust all over garage and give it a go first with hacksaw but most likely with angle grinder - I have a diamond wheel somewhere. Looking at holes 6 or 8 mm so from what you say it should be easy, if no hammer needed then my little pillar drill might do nicely.
 

MikeG.

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Richard_C":6t0q0ab8 said:
Thanks all, useful and encouraging information. Looks like it won't be as hard (in every sense) as I thought it might be.
Slate is extremely soft. You can scratch it with almost anything. It was used by kids in school instead of paper 100+ years ago who scratched its surface, writing with a piece of soapstone. ("Wipe the slate clean" comes from that.) It is generally cut by roofers using slate pliers (like hand held pliers/ scissors), a small guillotine, or a small hammer-like sharpened tool over a raised frame.

I will wait for a day when I can work outdoors to avoid dust all over garage and give it a go first with hacksaw but most likely with angle grinder - I have a diamond wheel somewhere. Looking at holes 6 or 8 mm so from what you say it should be easy, if no hammer needed then my little pillar drill might do nicely.
You could punch the holes through with a small punch, so long as the underside is well supported. That's how nail holes are done for slate roofing. And you don't need a diamond disc particularly.....any disc will do. Just as an aside, if you don't want to risk a drill bit you can use a Reisser-type self-cutting screw, albeit starting isn't quite so easy.
 

Trevanion

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MikeG.":1msd5y31 said:
You could punch the holes through with a small punch, so long as the underside is well supported.
Would that work on a 20mm thick piece?
 

MikeG.

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Trevanion":19tdxj1h said:
MikeG.":19tdxj1h said:
You could punch the holes through with a small punch, so long as the underside is well supported.
Would that work on a 20mm thick piece?
Eventually! :) There might be some collateral damage. I was more making the point that slate is extremely soft, not so much suggesting this for the job in hand which sounds like it needs to be a bit neater.
 

Lons

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MikeG.":25t4a2tq said:
Slate is extremely soft. It is generally cut by roofers using slate pliers (like hand held pliers/ scissors), a small guillotine, or a small hammer-like sharpened tool over a raised frame.`.
That reminds me I still have my guillotine and slaters hammers, must sort them out and get rid.

Richard. Out of general interest and just to confirm what Mike said, using a guillotine on roofing slates needs just medium hand pressure and feels like cutting through soft hardboard / hard cardboard and the slate flakes on the back of the cut to give that soft weathered edge you see when you look at a roof. Slaters hammers have a spike on one end used to punch the nail holes. There's also a little sprung punch that knocks out both holes at once but that's for wimps and if you're a "real man" you can cut the slates with the edge of a trowel. :)
 

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MJP

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Quote:"Slate is extremely soft. You can scratch it with almost anything. It was used by kids in school instead of paper 100+ years ago who scratched its surface, writing with a piece of soapstone. " Unquote.

Hah - not that long ago, I used a slate and stylus in my first primary school in Neath, in Glamorgan, back in the 50s.

Martin.
 

MikeG.

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MJP":uf9y9xrp said:
Quote:"Slate is extremely soft. You can scratch it with almost anything. It was used by kids in school instead of paper 100+ years ago who scratched its surface, writing with a piece of soapstone. " Unquote.

Hah - not that long ago, I used a slate and stylus in my first primary school in Neath, in Glamorgan, back in the 50s.

Martin.
:lol: :lol: Yeahbut Neath is 100 years ago, even now! :D

Seriously, what did you use to write on it with? You say a stylus, but do you know what that was made of?
 

AES

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I won't swear to it 100% MikeG, it's a long time ago, but when I started Primary School, 1950, SE of London (Kent) we used slates and had small sticks of chalk (I'm pretty sure) to "write"* on them.

* meaning scribble more like!
 

Trevanion

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I’m pretty sure we were still using slates and chalk 15 years ago or so here in the west.
 

MikeG.

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It's the chalk bit I'm curious about. I've seen reconstructed Victorian classrooms, and the kids weren't writing on the slate with chalk. That said, I can't for the life of me remember what they were using. The marks were scratched into the surface of the slate, then wiped off with a damp cloth.
 

AES

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MikeG.":1ozny67s said:
It's the chalk bit I'm curious about. I've seen reconstructed Victorian classrooms, and the kids weren't writing on the slate with chalk. That said, I can't for the life of me remember what they were using. The marks were scratched into the surface of the slate, then wiped off with a damp cloth.
Me too Mike. I only "think" I remember small sticks of chalk (coloured?) and I do THINK I remember a damp cloth to clean them again. But you're dead right, if not chalk (and I repeat, I'm really not sure about that any more) then WHAT was it???
 

AES

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Not being daft (hopefully)! Would a slate pencil be like a todays pencil but with the "lead" (graphite actually) replaced with a piece of slate? How would that write on a piece of slate please?
 

Lons

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I think they used white slate or limestone with or without a paper wrapping.
 
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