Flatten Arkansas Stones

[John Grossbohlin]

UNCLE!!! I've DAGed and Goggled and haven't come up with what I consider a good answer to the question of what to use to flatten Arkansas stones... I've got quite a collection of stones, accumulated over about 35 years, ranging from large soft stones to a large Black hard stone, along with assorted slips, etc. The soft stones in particular are no longer truly flat and the medium stones are a bit glazed.

Why Arkansas stones? Because when I started buying stones they were about the best thing available... India stones were the other choice and those I used were all glazed--I "found" them in my father's tool and die maker's tool box. ;~)--and they didn't work too well.

I'm considering the Woodcraft granite surface plate and wet-dry paper approach but wonder if a diamond stone would be better? I'm concerned that the courser diamond stones may actually make my medium and fine Arkansas stones too rough. Is there a consensus?

John

[Hambone Slim]

John: Silicon carbide lapping grit on glass will dress your stones nicely & quickly. Lee Valley has it:

90x & flat safety glass are all you will need.

This dosen't change the grade of your sharpening stones.

A sharpening oil of 50% light machine oil (3in1) & 50% kero will keep your stones cleaner, and give a more positive feel of the tool on the stone when sharpening.

-- Timothy Juvenal

[charlie b]

or you can get the Norton stone flattener. about the same size as a japanese water stone - diagonal grooves for slurry to escape into. about $26 US. works well and quick - at least on japanese waterstones. haven't had the need to try it on hard] arkansas stone.

charlie b

[bridgerfafc]

I've used wet/dry paper on glass, loose grit on glass and a coarse diamond stone. I haven't done it in some time- I don't use the natural stones much these days- but if I needed to flatten one now I'd use the diamond stone and finish with wet/dry paper on glass if it wasn't smooth enough for me.

[Australopithecus scobis]

How long does a glass plate last before it's too dished for flattening? The folks who grind their own telescope mirrors use elaborate patterns to get the dish shape they want. Seems we'd be well advised to look at their methods--then do something different--to keep our glass plates flat.

I'm guessing that one new glass plate would stay flat long enough to flatten at least a couple of Arkansas stones.

[Tom Dacon]

Along with the silicon carbide lapping grits, Lee Valley sells 8 x 10 sheets of thin soft clear plastic with a peel-off back. You put the plastic down on the glass sheet and then put the grit on top of that. The plastic is soft enough that the grit embeds itself in the surface, and leaves the underlying glass untouched. I've used it on a couple of stones and it works just fine. Takes a while though, even if you work your way through the grits from the coarsest. At least that was true for my stones, which had never been flattened in their lives.

Tom Dacon

[J. Clarke]

Use three stones and grind them against each other and you can obtain optical flatness if you're persistent and careful and have a reference flat to test against . Would help to obtain a book on lensmaking that goes into the hand grinding of optical flats before you start though.

[CW]

The three plate method is used to produce a reference flat, you don't need one to check against. This is far more precise and far more work than needed for a sharpening stone.

[Tex]

... maybe a dumb question, but why can't you use a good sized diamond hone to do the job? I know, you'd have to clean the crud/residue periodically, but I don't think a stone is gonna degrade it's flatness.

[J. Clarke]

You can and it works fine. I was being facetious. I see I left off the smiley.

[AAvK]

Those are cheaper at Craftmman Studion in San Diego. It's a website. They do work great for water stones. AAvK

[LDR]

I'm fairly sure I'm thinking of the same stone: $80 at Woodcraft and elsewhere I've seen it on the Net, although I don't remember the addresses.

Those are cheaper at Craftmman Studion in San Diego. It's a website.

Where exactly, please.

[DanG]

There is a less tiring method of flattening old garage sale stones and ones worn from long years of use/abuse.

Nail up a 4 sided frame large enough to contain all the stones. Install an eye bolt or similar to one face of the frame. Find a grand kid, neighbor kid, or young relative with a tricycle. Multiple operators are a plus. Attach frame to tricycle with an appropriate piece of rope. Find an suitable expanse of concrete drive or patio surface, preferably with shade available. Beer cooler optional, but sure helps the process. You can water the slab to accelerate progress. Install all stones in the frame(s) and let the grinding begin. This method can take up to a full case of beer to properly supervise.

______________________________ Keep the whole world singing . . . . DanG (remove the sevens) [e-mail]

[AAvK]

[LDR]

Thanks for following up. The flattening stone is not the same, nor does it look as nice, as the one I had in mind. However, no reason why it wouldn't work, and the price is certainly right.

[AAvK]

Which one did you have in mind, may I ask? Because every other one I have seen anywhere online, other than this model by Norton, is HUGELY expensive. Besides that, these Norton are really not all that hard, they chip a bit easily and are designed for Norton's water stones, which I have. It works great for them tho... I just would not even attempt to flatten an Arkansas stone on one, the Arks seem to be much harder in all reality, seriously, but it is your money. Ark stones are a highly pressure compacted silicate sand, which is rock, not ocean sand which is sea shells. The Norton flattener is lightly compressed aluminum oxide or silicon carbide. Not a good combo IMO.

[LDR]

Which is why I jumped into the thread. The one I saw at Woodcraft really looked nice, and maybe it should for $80. Not aware of other flavors of the stone I thought maybe I was overlooking a bargain. Anyway, as you say, if $18 (price I just saw at Craftsman.Com) does the job, what the hey.... Larry

(snip)

[AAvK]

So, what kind of stones do you need to flatten? Because if they are Arks I would seriously consider thick glass and abrasive paers such as AO. Even dry wall screen sheets. Anything that is tougher than the stone itself. AAvK

[John Grossbohlin]

After a busy weekend I've finally gotten a chance to read the responses to my initial inquiry. Dry wall screen is something I hadn't even considered... got a bunch of that in the shop in anticipation of rerocking the family room and living room. Think I might give that a try with some of the big soft Arkansas stones simply because they are big and a diamond stone large enough to accommodate them would be hugely expensive--it would be cheaper to buy new soft stones once in a while!

The silicon carbide lapping paste sounds interesting too as does the granite block with wet and dry paper. Maybe I'll try all three approaches to see what I like best!

Thanks for the interesting responses! DAGS was making me nuts as the threads deteriorated fast in many cases!

John