Arkansas stone cutting speed and limits

[Chasingsharpness]

I recently got a soft ark and I've been enjoying it so far. It looks beautiful and feels great. It cut really slow however on soft stainless and carbon, and it did basically nothing on SG2.

Is there anything I can do to speed up the abrasion rate, like lap the stone with a diamond plate or another friable synthetic?

Also I was wondering what are the limits of this stone. That is to say which steels will it cut and which are the limit.

Are hard arks or hard black arks any different in this regard? I assume they have the same abrasives.

 

[Mr Kooby Shemayrew]

I recently got a soft ark and I've been enjoying it so far. It looks beautiful and feels great. It cut really slow however on soft stainless and carbon, and it did basically nothing on SG2.

Is there anything I can do to speed up the abrasion rate, like lap the stone with a diamond plate or another friable synthetic?

Also I was wondering what are the limits of this stone. That is to say which steels will it cut and which are the limit.

Are hard arks or hard black arks any different in this regard? I assume they have the same abrasives.

Arks are all the same material which is fairly large grain novaculite. The only real difference is how tightly the grains are packed. When packed tightly you get the translucent, surgical blacks, and a few other variations which can finish like an extremely fine synthetic stone.

At the opposite end of the spectrum are the less densely packed varieties and these act like somewhat coarser stones. Just keep in mind that synthetic stones have a sweet spot, let’s say 2K grit on down, where they are really king of the hill.

Arks are of a composition and hardness that allows some abrasion and some polishing at the same time. Yes, they tend to be slow, but oftentimes edge quality will exceed that of a similar grit synthetic stone. Because of this reduced aggression, they can be even slower on some steels, highly abrasion resistant steels in particular.

I have a washita which is like an extra soft Soft Ark. I like to prep it with 60 to 120 SiC to give it a very rough surface, then I use it dry. This gives it the best cutting speed it can achieve. The edge quality is still very impressive.

 

[HumbleHomeCook]

In terms of speed, it somewhat depends on what you're comparing it to but, in general, they aren't overly fast stones. Don't be afraid to use some pressure on them to get started though. That can speed things up.

They're not going to be very good at sharpening SG2 and similar more complex steels. SG2 has a boatload of chromium and decent bit of vanadium. I don't know how much of those elements form carbides in the finished product but it's quite a bit. Those vanadium carbides are very hard, much harder than novaculite. You can't abrade them with an Ark. You'll only abrade the surrounding matrix and burnish the carbides. The chromium carbides are hard as well but less so. However, given the abundance of chromium in the steel there's probably a lot of those carbides to deal with as well.

Don't confuse Rockwell hardness with carbide hardness. Steels can have a high Rockwell hardness but still be sharpener friendly, such as the ubiquitous shirogami.

Arks can handle "simpler" stainless but soft stainless sucks on everything.

Here's a good site that allows you to look up and compare steels. Vanadium is a key element to look at:
http://www.zknives.com/knives/steels/steelgraph.php?nm=SG2&ni=576&hrn=1&gm=0
Also, if you're not using oil, be very conscious of not allowing the surface to clog.

 

[captaincaed]

If you want a faster cutting arkansas, then you want a Washita.
https://www.kitchenknifeforums.com/threads/the-washita-thread.53968/Keep in mind modern washita with purple banding are a different beast than the vintage, no longer mined washita you can find from those ebay sellers. However, they're still much faster than a soft Ark.

I've found a super coarse surface texture doesn't help much with cutting speed, and leaves my edges more ragged than I like. I like a stone prepped with ~220 grit sandpaper..but play around, there's no rules.

They'll still cut slower than any decent modern synthetic. Use naturals for the joy, not the speed.

I often let synthetic stonea do my coarse/medium.work, then jump to naturals. Naturals are also great for touch ups. Throw away your honing rods and use a natural instead. (Maybe keep the rod for that sg2 steel, it's a turd to sharpen well, but gives great results when you do).

 

[Desert Rat]

I recently got a soft ark and I've been enjoying it so far. It looks beautiful and feels great. It cut really slow however on soft stainless and carbon, and it did basically nothing on SG2.

Is there anything I can do to speed up the abrasion rate, like lap the stone with a diamond plate or another friable synthetic?

Also I was wondering what are the limits of this stone. That is to say which steels will it cut and which are the limit.

Are hard arks or hard black arks any different in this regard? I assume they have the same abrasives.

I use both an old diamond plate and other stones. They don't work any better and probably not as well as sic powder or wet dry paper but are usually at hand and a matter of convenience. Anything to keep the surface from glazing over works. Just know that arks are really hard on diamond plates so don't use a plate you care about.

 

[Chasingsharpness]

Is the hard and hard black ark much different from the soft ark in terms of sharpening feeling?

 

[HumbleHomeCook]

Is the hard and hard black ark much different from the soft ark in terms of sharpening feeling?

No. Well, they're harder. The harder they are the finer as well.

Arks are hard, non-shedding rocks. Very different to Belgians and J-Nats.

 

[Mr Kooby Shemayrew]

Is the hard and hard black ark much different from the soft ark in terms of sharpening feeling?

A quality hard black like Dan’s feels like frosted glass out of the box and just like glass after burnishing. It is at the far opposite end of the spectrum from a Soft Ark.

A basic Hard is somewhere in the middle.

And yes the sharpening feedback is very different for each. Fortunately, Arks are known for having great feedback.

Here is a review from Burrtection…. A couple caveats: the stones he uses are probably inexpensive varieties, not the high-end stuff like Dan’s. And he did zero preparation of the stones. No flattening, no edge beveling, no surface prep. He gave them high regards but it would have been higher had he properly prepped them before use.

 

[captaincaed]

Your angle control on a hard or black Arkansas stone needs to be pretty good. If you lift the spine too much, you’ll start damaging the edge fairly quickly. Or at least rounding it, or flattening it. The soft Arkansas is a bit more forgiving, but not as forgiving as a Japanese natural stone, or a synthetic stone.

they’re a great pursuit, but if you don’t get great results, right away, stick with it. Realize it takes a little practice, both on angle control, and matching the steel to the stone. The harder Arkansas stones cut quite slowly. I have much better luck with them on simple Carbon steels.

 

[M1k3]

Arks can handle "simpler" stainless but soft stainless sucks on everything.

Diamond stones make soft stainless seem like you're sharpening simple carbon steels.

 

[HumbleHomeCook]

Diamond stones make soft stainless seem like you're sharpening simple carbon steels.

I use diamond on a lot of stainless for sure.

 

[Chasingsharpness]

Diamond stones make soft stainless seem like you're sharpening simple carbon steels.

Is this the case for resin bonded diamond stones?

 

[M1k3]

Is this the case for resin bonded diamond stones?

Yes, it's actually what I'm referring to. Venev in particular. I have a Sankyo one that's also good, but, I believe it's discontinued.

I haven't used any other brands, yet. NSK is getting high praise though.

 

[Chasingsharpness]

Thanks much appreciated, I am also looking at an NSK which would be my first resin-diamond.