Is this sandstone any good?

[tess_lawrie_fan]

I can get a sandstone (arenite) for less than $9 (shipping included), but my guts are saying that's a very bad deal. Too coarse, too soft... Not useless, of course, but adds nothing to the tools I already have.

https://zebu.com.br/produto/pedra-de-afiar-e-amolar/

I'm open to experiment with new toys, but... apart from that, is there any reason to get this stone?

 

[Baron Mind]

Looks cool. I'd give it a try

 

[tess_lawrie_fan]

Looks cool. I'd give it a try

Thanks for the input. I agree, but I'm trying to get an excuse to not buy it.

 

[Obsessed with Edges]

Depending on the steel types you're sharpening, a natural stone may or may not work so well.

If you're sharpening wear-resistant steels with significant hard carbide content, like 440C, D2, S30V, etc., a natural stone will struggle with it and the stone might also glaze, i.e., get polished by the carbides, if it doesn't readily shed and expose fresh grit while working. If it glazes, it effectively stops working for any steel tried and would need frequent resurfacing (lapping) to keep it working well. Most hard carbides (chromium carbide, vanadium carbide, tungsten carbide) are 2X or more harder than the grit in natural stones, which is why sharpening wear-resistant steels will be difficult on them.

If it's used for simpler plain carbon steel (1095, CV, etc.) or low alloy stainless (420, etc), it should likely handle those OK.

 

[tess_lawrie_fan]

Depending on the steel you're sharpening with it, a natural stone may or may not work as well.

If you're sharpening wear-resistant steels with significant hard carbide content, like 440C, D2, S30V, etc., a natural stone will struggle with it and the stone might also glaze (get polished by the carbides), if it doesn't readily shed and expose fresh grit very well. If it glazes, it effectively stops working for any steel tried and would need frequent resurfacing (lapping) to keep it working well. Most hard carbides (chromium carbide, vanadium carbide, tungsten carbide) are 2X or more harder than the grit in natural stones, which is why wear-resistant steels will be difficult on them.

If it's used for simpler plain carbon steel (1095, CV, etc.) or low alloy stainless (420, etc), it should likely handle those OK.

Thanks for the detailed explanation! I may look for a harder, good quality natural stone in the future, but for a newbie like me, synthetic stones are still the way to go.

 

[Obsessed with Edges]

Thanks for the detailed explanation! I may look for a harder, good quality natural stone in the future, but for a newbie like me, synthetic stones are still the way to go.

Natural stones can be fun & rewarding to use on steels compatible to them, and there's something that just feels intuitively 'right' in using them for more traditional knives. Some steels 'like' a certain stone, and vice versa. So, at some point down the road, they could still be worth looking into. But, with many modern steels these days, sometimes they can't live up to expectations that may be set unrealistically high.

 

[tess_lawrie_fan]

Natural stones can be fun & rewarding to use on steels compatible to them, and there's something that just feels intuitively 'right' in using them for more traditional knives. Some steels 'like' a certain stone, and vice versa. So, at some point down the road, they could still be worth looking into. But, with many modern steels these days, sometimes they can't live up to expectations that may be set unrealistically high.

As a beginner, I do all experiments I can — like using the bottom of a mug or building my own strop. But the knowledge you're describing will require a lot of experience (attentive experience, I mean).

What you mean by "traditional knives"? Carbon steel knives?

 

[Obsessed with Edges]

As a beginner, I do all experiments I can — like using the bottom of a mug or building my own strop. But the knowledge you're describing will require a lot of experience (attentive experience, I mean).

What you mean by "traditional knives"? Carbon steel knives?

Yeah, carbon steel and the low-alloy stainless blades usually found in the 'old school' traditional slip-joint patterns (see the Traditional forum on the site, for examples). Steels like 1095, CV and 420HC, 440A are often used in those and will usually sharpen up pretty well on natural stones. The carbon steels in particular, like 1095 and CV, really refine well on a natural stones like quality Arkansas stones.

 

[tess_lawrie_fan]

Yeah, carbon steel and the low-alloy stainless blades usually found in the 'old school' traditional slip-joint patterns (see the Traditional forum on the site, for examples). Steels like 1095, CV and 420HC, 440A are often used in those and will usually sharpen up pretty well on natural stones. The carbon steels in particular, like 1095 and CV, really refine well on a natural stones like quality Arkansas stones.

Thanks, that's nice to know. I don't have any fancy steel, just the usual stuff: a small collection of 420A, 440C and carbon steel folding knives, and a useful collection of Tramontina Century kitchen knives (1.4116 steel). I'm also eagerly waiting for the making of some military/outdoor style forged knives (6150c). I don't see myself as a owner of an incredible collection, but of course I want a decent edge in each blade I have.

So, based in what you've said, I will definitively pick up a good natural stone in the future, Arkansas or other.

 

[scdub]

I’d give it a try for $9.

Next to coarse diamond, sandstone is probably the fastest cutting medium I’ve found for grinding metal. Coarse grits seem to work fine even on PM/high carbide steels. I’m just using sandstone rocks that I find and flatten down however, so if you’ve got natural sandstone in your area you can save $9 if you put in a little work...

I dream of one day having a big old sandstone grinding wheel...

 

[tess_lawrie_fan]

I’d give it a try for $9.

Next to coarse diamond, sandstone is probably the fastest cutting medium I’ve found for grinding metal. Coarse grits seem to work fine even on PM/high carbide steels. I’m just using sandstone rocks that I find and flatten down however, so if you’ve got natural sandstone in your area you can save $9 if you put in a little work...

I dream of one day having a big old sandstone grinding wheel...

I've found a sandstone like that many years ago, and gave it to my girlfriend.

A big sandstone grinding wheel would be something!

 

[Papilio]

I don't speak Portuguese. But as far as I unterstand the grit is 50 and 120? That is indeed coarse. Extra extra coarse. I don't see a regular use of such a coarse grit. Eats away your blade in next to no time.
As ist is a natural stone, I ask myself how they are able to rate that stone that exactly?

 

[tess_lawrie_fan]

I don't speak Portuguese. But as far as I unterstand the grit is 50 and 120? That is indeed coarse. Extra extra coarse. I don't see a regular use of such a coarse grit. Eats away your blade in next to no time.
As ist is a natural stone, I ask myself how they are able to rate that stone that exactly?

Exactly!

You understood correctly the information, and yes, how in this world can a natural stone have two grits?

 

[Obsessed with Edges]

Exactly!

You understood correctly the information, and yes, how in this world can a natural stone have two grits?

It's possible. Some manufacturers will use two different slabs of cut stone, epoxied back-to-back, to make a 2-sided stone with different grits. This is often done using a coarse stone of synthetic grit, like silicon carbide or aluminum oxide, and a fine natural stone for finishing. But it could just as easily be done with two slabs of natural stone.

 

[tess_lawrie_fan]

It's possible. Some manufacturers will use two different slabs of cut stone, epoxied back-to-back, to make a 2-sided stone with different grits. This is often done using a coarse stone of synthetic grit, like silicon carbide or aluminum oxide, and a fine natural stone for finishing. But it could just as easily be done with two slabs of natural stone.

Very interesting! I would never guess that. There's more pics of this sandstone at Amazon:

https://www.amazon.com.br/Pedra-Natural-Tripla-Amolar-Lâmina/dp/B07C4LYMQS/

Curiously, Amazon says that the stone has a "triple face" (tripla face). I don't know what a "triple face" could possibly mean... Anyway, after a closer look, the stone really seems to have two different sides.

I already have a very good coarse SiC stone (120/240), so I wonder if I really need this one.

 

[Obsessed with Edges]

Very interesting! I would never guess that. There's more pics of this sandstone at Amazon:

https://www.amazon.com.br/Pedra-Natural-Tripla-Amolar-Lâmina/dp/B07C4LYMQS/

Curiously, Amazon says that the stone has a "triple face" (tripla face). I don't know what a "triple face" could possibly mean... Anyway, after a closer look, the stone really seems to have two different sides.

I already have a very good coarse SiC stone (120/240), so I wonder if I really need this one.

No idea what 'triple face' would imply there.

Past a certain point, if one has already accumulated many stones, there's usually not a genuine need for more stones. But, especially if they're not expensive, there's never any harm in trying others in order to satisfy intellectual curiosity. I've bought WAY more stones & other sharpening gear than I ever actually needed. But in trying each and every one of them, it reveals more about the possibilities & capabilities of the various products out there. Also, trying many examples will reveal characteristic behaviors of the different abrasive types and the wide variation in the quality of products out there. It becomes easier to recognize where the line is, between good quality and not-so-good quality stones.

 

[tess_lawrie_fan]

No idea what 'triple face' would imply there.

Past a certain point, if one has already accumulated many stones, there's usually not a genuine need for more stones. But, especially if they're not expensive, there's never any harm in trying others in order to satisfy intellectual curiosity. I've bought WAY more stones & other sharpening gear than I ever actually needed. But in trying each and every one of them, it reveals more about the possibilities & capabilities of the various products out there. Also, trying many examples will reveal characteristic behaviors of the different abrasive types and the wide variation in the quality of products out there. It becomes easier to recognize where the line is, between good quality and not-so-good quality stones.

Great post. It sets a scheme that is valid not only for the "blade world", but in general.

After all, that's why I've opened this thread: I don't need this sandstone, but I'm tempted to buy and try it.

I probably have more blades than the average guy, and I certainly want to know how to sharp them better than the average guy. And of course I have the necessary intellectual curiosity to explore this world — to a certain extent. I don't want to be the guy that — not being a master — buys all available toys just because he can. I already have a 120/240 stone, and two Suehiros, 320 and 1k; in the future, I may want to have a 4k or 5k. That's how I see things right now. However, I'm open to learn, and that's why I'm here.

 

[Papilio]

I have no idea, what a triple face could be. The instructions on the linked Amazon page seems to say that you start with the most spongy side. After that you use the smoother side and finally the smoothest side? I should learn a foreign language
So it seems to be a double stone with three different grits? Maybe one of the sides? It is a little bit strange.
When are into sharpening it is always a question how many stones or other sharpening tools one need. Your SiC (120 / 240) is a good basis. The sandstone won't give you anything the SiC can't do. Except all those thoughts Obsessed with Edges mentioned. A finer stone (4 or 5k) for honing sounds like a good idea.
Just to be sure: Suehiro 320 and 1k are rated in JIS. Your SiC probably isn't. I always struggle with those different standards. Because that makes it more difficult to compare stones.

 

[tess_lawrie_fan]

I have no idea, what a triple face could be. The instructions on the linked Amazon page seems to say that you start with the most spongy side. After that you use the smoother side and finally the smoothest side? I should learn a foreign language
So it seems to be a double stone with three different grits? Maybe one of the sides? It is a little bit strange.
When are into sharpening it is always a question how many stones or other sharpening tools one need. Your SiC (120 / 240) is a good basis. The sandstone won't give you anything the SiC can't do. Except all those thoughts Obsessed with Edges mentioned. A finer stone (4 or 5k) for honing sounds like a good idea.
Just to be sure: Suehiro 320 and 1k are rated in JIS. Your SiC probably isn't. I always struggle with those different standards. Because that makes it more difficult to compare stones.

I'm starting to see the Amazon's "triple face" as a poetic thing, like "the third bank of the river".

The different grit standards are really confusing! The Suehiro brand is missing from the most recent tables by Mr.Wizard, so I suppose it's included in the JIS R 6001 category. If I'm understanding it right, it's difficult to know the grit of some stones (like my SiC), and even more difficult to know the grit of a natural stone. Because of the mess, I try to keep up with the references but I don't bother too much. After all, it's my actual experience with a particular stone that counts.

I had good experiences with the strop I made. I've sharpened three blades and... dulled one , so I'm still learning how to deal with it. Last but not least, I'm having a terrific experience with a cheap ceramic stick. It works amazingly well. So I'm not planning to get my 4k/5k stone right now. I almost got a King 4000 S-45 that's available in my country, but decided to wait and research while I'm learning and practicing.

 

[Mr.Wizard]

The Suehiro brand is missing from the most recent tables by Mr.Wizard, so I suppose it's included in the JIS R 6001 category. If I'm understanding it right, it's difficult to know the grit of some stones (like my SiC), and even more difficult to know the grit of a natural stone. Because of the mess, I try to keep up with the references but I don't bother too much. After all, it's my actual experience with a particular stone that counts.

I have found it very difficult to get or find confirmation that Japanese whetstone manufacturers actually comply with JIS R 6001. Without specific knowledge to the contrary it seems like a reasonable assumption.

For bonded grits 220 and coarser the situation is simpler as revision 13 of the GLGC attempts to show. Most of the standards have essentially the same specifications for these.