[OP]
Member
In an effort to spend less time stropping I bought a "black surgical Arkansas" stone. I've never actually had a new natural stone before. This stone seems to be anything but "surgical" and leaves a fairly rough finish. Should I expect the stone to be smooth in the beginning or do I need to do something to lap it? It was a $100 stone, so it's not like I bought a cheap one.
Member
My black Arkansas stone came polished like piece of glass when it was new in 1976. It has lost less than .001 inches in thickness since then, so it wears very slowly.
Today some think that an Arkansas should be roughed up so it cuts faster. However a rough stone will not polish very well. A soft Arkansas stone that is left rough will eventually wear to the point that is gives a polish, but a black stone is more dense will wear very very slowly.
Contributor
Oil stones do need a break in period if your goal is a polished edge. The particles of novaculite (the abrasive in Arkansas stones) are only a little harder than O1 steel, according to The Perfect Edge by Ron Hock, and will round off a bit as you use the stone. This slows the cutting process and makes the effective grit finer. Or, you can treat them like water stones, periodically flattening them and wearing away the surface to expose fresh abrasive and keep them relatively coarse and fast cutting.
Also, as has been discussed here previously, shiny/polished and sharp aren't synonymous. You can have a cloudy looking edge that will cleanly shave end grain pine or a polished edge that will crush and tear it (and vice versa).
Last edited by Michael Bulatowicz; 12-03-2019 at 2:47 PM. Reason: Typo
Contributor
From my experience with "black Arkansas" stones my best seems to be from Dan's Whetstones. It was slightly rough when it arrived, but quickly became very smooth. It does leave a polished surface.Originally Posted by Warren Mickley
The other two are somewhat rough. Neither polishes or removes metal very well. One of them came from a yard sale and one of them came as a set for ~$40 at Woodcraft.
So by my experience/opinion, not all "black Arkansas" stones are the same. As always, YMMV!!!.png
jtk
"A pessimist sees the difficulty in every opportunity; an optimist sees the opportunity in every difficulty."
- Sir Winston Churchill (1874-1965)
Contributor
https://sawmillcreek.org/showthread....Arkansas-stone
https://sawmillcreek.org/showthread....rkansas-Stones
I cannot find the advise at the moment, but, it was recommended to me that I needed to use the Arkansas stone differently than my water stones in that I should not simply work the bevel, polish the back, and consider it done. It was recommended that I polish the bevel, then polish the back and bit then polish the bevel again (but less), then polish the back (but less), etc...... And I indeed had a bit better luck with that.
If you lived in the middle of Ohio, I would say bring them on over... :-)
My Arkansas stones are still relatively new and even my finest stone will leave a hazy finish compared to my water stones, which leave a mirror finish.
Andy
Member
Andy,
That is known as "chasing the burr". Truth is you should do the same with any polishing stone.
ken
Member
About a year ago I bought a hard Arkansas stone to try out as my final stone for my oilstone setup. Over time the hard Arkansas has smoothed out to the point I'm considering re-dressing the surface to get it cutting a bit more aggressively again. I've been quite happy with it. With some light stropping as a followup, I've able to consistently get a hair-popping edge. It's probably not as polished as I could achieve with a high-end waterstone, but the edge I get is always sharp enough - and I've done a lot of chisel work in white pine over the last year!
I'll probably spring for an 8" x 3" translucent Arkansas in the future.
Contributor
Interesting.... I had no idea. I will have to try that on my 16,000 glass stone to see if I can notice a difference. I saw a big difference with the Arkansas stone for sure.
Thanks Ken, very useful indeed.
Andrew
Member
This!
Warren speaks with decades of experience, earned in his everyday profession. If you wish to duplicate his stone, contact a used tool dealer, such as Patrick Leach, telling him exactly what you are after.
If the thunder don't get you, the lightning will.
Contributor
Yes, a hard arkansas used for polishing will need to be very smooth. The surface should feel like glass, as Warren described.
Sounds like your stone has a rougher surface finish than is ideal. Some vendors do a better job than others- Dan's is very good in my experience.
First thing I would do is check that it's flat. I'm suspicious that something was off in this vendors surfacing process. If it's not flat I would consider returning the stone to the vendor if possible. You can flatten it yourself but I wouldn't want to do that on a $100 stone.
If it's flat, then your issue is just the surface roughness. It will wear finer just from normal use. If it is currently intolerable and you want to speed up the process, you could a few things. First I would work some hard tool steel on the stone, like the back of a plane iron or something- work it all over the surface for as long as you can stand. Use a very light film of oil. If you have an A2 or HSS iron, that should speed this up. You can do this for a few minutes every sharpening session. It shouldn't take too long before you see significant improvement.
You could also try lapping with very fine sandpaper- maybe 1500 grit. Down to micron paper if you have it. Shouldn't take long if the stone is flat. You could also work some hard tool steel on the stone, like the back of a plane iron or something- work it all over the surface for as long as you can stand. If you have an A2 or HSS iron, that should speed this up.
Once you get it to an acceptable level, just keep using the stone and it will get finer and finer for the rest of its life. At this point you don't ever want to touch it with sandpaper or diamond hones, or any sort of abrasive- you will only make it coarser.
[OP]
Member
Thanks, all. I spent a few minutes with the tone on a diamond plate and it seems better. More to come.
Member
Andy,
High grit number stones make a smaller "wire edge" than stones with larger grit such as Ark stones vs. greater than 8000 grit water stones. It is still there but smaller and usually easier to get rid of depending on cutter being sharpened. Another factor is many folks equate "shiny' with sharp, in other words the shinier the bevel/back the sharper the iron. That just ain't so. Many of the best natural stones will leave a "smoky" surface vs. a very shiny surface. It is all related to the scratch pattern, shape and depth of the scratches. Bottom line: a scratch with a near vertical face will reflect more light and look shinier than one with more rounded edges such as you get with many natural stones.
A natural polishing stone will produce as sharp an edge as the highest grit synthetic stone, it will likely be smokey vs. shiny but just as sharp and it is also likely to stay sharp longer because of the differences in scratch pattern.
Of course, as always with everything wood and sharpening, YMMV, and also as always I could be full of horse plucky.
ken
Last edited by ken hatch; 12-04-2019 at 9:44 AM.
Member
In the eighteenth century, and for centuries before that, craftsmen used water stones for sharpening and oil stones for polishing. In other words the tool was made sharp by the water stones and the job of the oil stones was to smooth out the scratches made by the coarser stones. The Arkansas stones are good at polishing, removing scratches; they are not good at removing material once a smooth surface has been achieved. Arkansas stones cannot be put on a spectrum with harsh water stones.
About the burr: Water stones have loose grit or slurry flowing on the surface of the stone. This tends to beat up the little sliver of foil we call the burr. Arkansas stones tend to be without slurry, so the burr remains intact and has to be removed.
Contributor
That makes a lot of sense. And that sounds exactly like what I am seeing (in that it leaves a hazy pattern from the Arkansas stone).... many folks equate "shiny' with sharp, in other words the shinier the bevel/back the sharper the iron. That just ain't so. Many of the best natural stones will leave a "smoky" surface vs. a very shiny surface. It is all related to the scratch pattern, shape and depth of the scratches. Bottom line: a scratch with a near vertical face will reflect more light and look shinier than one with more rounded edges such as you get with many natural stones.
A natural polishing stone will produce as sharp an edge as the highest grit synthetic stone, it will likely be smokey vs. shiny but just as sharp and it is also likely to stay sharp longer because of the differences in scratch pattern.
Of course, as always with everything wood and sharpening, YMMV, and also as always I could be full of horse plucky
ken
What little I know about this, it sounds reasonable to assume that a rounded scratch would be less likely to break down.
Ken, you may be full of horse plucky, but it all sounds reasonable to me.
Learning a lot more from this thread than I expected. I also agree with your thoughts on raising a burr, but, Warren's reply I think adds to it...
Contributor
I had not considered that...... but it makes sense.
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