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By Osvaldd
Sorry for the click-bait title. :twisted:
I came across a pile of slate stones, brought a few home, flattened one and tried to sharpened a plane blade. I was amazed at the results. It's quite fast and gives a fine scratch pattern, few strokes on the strop and I was shaving hair. wow.
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By Trevanion
Welsh black slate is revered by some barbers for sharpening razor blades. All the local stuff we have around here is quite bright blue and very soft though, otherwise, I would also be opening a business venture! :lol: I think the harder stuff comes from up northwards (Naturally... :roll:)

Quite a few people selling new black slates on eBay for about £30 or so a stone.
By D_W
I can tell it's slate (hadn't read your question) just by the slurry on the stone.
Slates are a bit slow for their fineness, and the edge they make can be a little bit toothy and harsh (from a shaving perspective), but there's no issue with them like that for tools.

Good for vintage steel, but will be a bit tired on tools on the hard side or modern and hard side (as in, tools with chromium and such in them).

Water of ayr is *highly* desirable for razors and a good clean one with little use in a larger size can fetch $200-$400.
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MikeG. wrote:I've got a pile of slates left over from a roof. I can see a lucrative sideline opening up for me... :)
Think of a catchy name for the slate method, and you're laughing. £80 per slate.

Sent from my SM-G973F using Tapatalk
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By Osvaldd
It seems that this slate prefers water as lubricant, I tried mineral oil and it created a very thick messy slurry I think it was slower with oil as well.

If someone wants a piece give me a shout on PM, I might be able to find smaller stones(most are big 5-10kg chunks though).free+p&p
Last edited by Osvaldd on 07 Nov 2019, 21:58, edited 1 time in total.
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By Ttrees
I was only pondering the other day about trying out some old stones lying about for the craic.
I wonder if anyone has done any research on the results of using various common type stone in the UK and Ireland.
It seems that sandstone in Fermanagh county was popular for scythes. (there's now 37 hands videos on YT in a playlist)
I would love to see what types would be the best to shoot for.
Kinda surprised this hasn't come up in the last few years.

I feel ignorant about not knowing what the composition of the stones are, or anything about stone really.
I presume the stone carvers know all about this, and could give you a list in order of preference
and of grit sizes, and even knowledgeable about the qualities of a same type of stone from various locations.
Is slate a type of limestone?
The only types of stone that I could name out is limestone, sandstone, basalt, granite, and whatever greywacke is that's in Drogheda which was used for Newgrange megalithic tomb/call it what you will. It was more easily cleft as it comes out of the ground vertically there, and might differ from the horizontal stuff
Just trying to see if the stone differs from the regular stuff,
I.e... If I find an auld slate will it be as good, or should I try out a few from various places.
I wonder if a Bangor blue slate would have the same qualities as the welsh type that looks darker.

In the north of the Island I believe that flint from there was sought after (Ray Mears programme I think, I might stick this in if its of interest and I can find it.)

Across the pond you guys have a few sought after stones aswell
The Welsh slate which is still in production by Inigo Jones. ... ng-stones/

The other two in the UK I know of are the Water of ayr/Tam O'Shanter in Dalmore quarry in Scotland, Is also called a dragon's tongue?
and Charnley forest from northwest Leicestershire (possibly incorrect from a quick Googling)

Apart from these, I've not heard of any type being used for tools
and never heard of anyone using a local stone for their finer edge tools.

There must be a juicy thread somewhere in the archives about this.
Last edited by Ttrees on 07 Nov 2019, 21:53, edited 1 time in total.
By D_W
Oil will shut down their cutting speed. Generally used with water unless they're too coarse for a razor, and then oil is used to glaze them over a little bit and slow them down.

Stick with the water for tools.

Most slates can be cut pretty easily with a used hacksaw blade or coping saw blade, and will cut fine for a while even as the teeth on the blade wear, they'll just rasp material off. Wear a dust mask if doing so.

I hand cut japanese and slate stones in a plain old multi purpose bench vise with a coping saw fairly regularly. watch out for heat - something with set is better, but used fine dry if there's enough. If there's too much heat, you'll find out quickly with a blade breakage. Water added to the cutting process just makes for a slimy mess.
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By AndyT
Ttrees wrote:There must be a juicy thread somewhere in the archives about this.

You could start here for the links I found when I bought a slate hone.


Somewhere I have a bookmark to a Dutch site which has the sort of research you want. I'll post a link if I can find it.
By dannyr
Roof slates can be a bit variable, but available by the thousand in some parts - select the best.
I used very good slab slate (broken mantle shelf in a skip) many years ago when I'd only heard of 'oil'stones … lovely 6x12x1.5" flat stone which was reasonably easy to cut with an old worn hardpoint handsaw (with water). Tried thin oil but then cleaned it off with soap and water and used the same for a better lube - great for back flattening and sharpening, hard work if major repair is needed, quick hone on a hard strop after can help, but not really nec. Wears quite quickly - make two and rub together for flattening. Some years later I heard of the v expensive natural Japanese water stones. Still have this large flat slate, but also alternatives such as diamond, which I tend to use, plus a large Charnley Forest/Charnwood/Charlie stone for hone.
Go for it - try your local stones (if you cut with angle grinder - easy - do it outside, away from people, wet the cut and wear a mask and eye protection).
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By ED65
A few members have tried this over the years and their varied experiences showcase how variable slate is as a material. Some will work fine, others work okay-ish, not great but usable in a pinch. And some just isn't suitable (too soft, too flaky, gritty inclusions constantly being released, possibly a combination).

Slate can work well as a final fine hone so it's great if you do find a piece that's suitable obvs. I was quite pleased with the performance of the two commercial slate hones I've picked up secondhand over the years, although one was noticeably superior to the other and I was far more tempted to make it a keeper.
By lurker
As I can just about see what was thought to be the best quarry (whittle hill) for Charnwood stones from my house, I have looked into the history and geology a fair bit.

I have no idea about how the charnley name came about; it’s either a corruption or confusion with some (inferior) stone up near Derbyshire. There is a hamlet a few miles away called Charley that has a few outcrops.

The hills around Charnwood are remnants of a massive volcano rim which is the source.
There is also slate in the area as well (I have a lump of broken door step that is smooth Swithland slate and it is a decent hone).

Until stone started to appear from USA there was a thriving industry locally. 15 miles to the south there is even a village called Whetstone: my personal theory is this was a centre for trading with other parts of the country as it is on what was the main road to London and the south, but has no stone itself. I can’t find any evidence to back this however.

I have several nice whittle stones, which as you might imagine are more common around here if you know what you are looking at.