Arkansas Translucent/Surgical Black

[hobber]

Dan's site has a good presentation of this. It all boils down to stone density (specific gravity). Some trans are denser than blacks, and some blacks are denser than trans are. From Dan's site:

Bottom line is that I have found that both my trans and black finish the same...very slowly, but the resulting edge is very sharp!

 

[Gamma]

Gamma,I am a little surprised...

My opinon is based on actual hands-on use, a lot of research, and extensive side-by-side comparison.

In a very technical sense, if all things are equal, translucent stones are finer than blacks. I'm talking about comparing black/trans stones in the same range of specific gravity with identical crystalline structure. SG can be increased by the inclusion of impurities - for example, the presence of hematite will increase SG, but it won't increase the stone's ability to sharpen finer edges. So a denser stone is not neccessarily finer. And there are 'grades' of translucency and stone quality that factor in very much the same way also.

That said, there are old-school woodworkers that prefer slight softer very dense Arks, usually blacks. And they differentiate between shades of grey here; they don't like the gemstone quartz type of translucent Arks, and they'll tell you that they get better results on the black stones that are still super hard but have zero translucency. I think this speaks to technique and needs mostly.

Geologically, the difference between black/trans stones of similar density is that the black stones have inpurities that the translucent stones don't. And the translucents have a higher percentage of pure colorless silica due to a lack of impurities. When comparing stones of similar cryatalline structure, higher silica content allows for greater fine-ness because it is the silica crystals that are doing the cutting. Iron oxides that increase specific gravity do not add to the cutting/polishing capability.

For the most part, in practical use, all of those stones will both take identical edges to, virtually, the same place. And I am sure there are variations upon the theme where some black stones may possibly be uber exceptional. Mother Nature is funny like that. At the same time, I've been listening to the SB vs Translucent arguement for many decades.
Stone by stone, person by person, on any given day.... mileage varies and preferences rule the day.

But my main reason for choosing Dan's Translucent over his 'ultrafine' black is my prefernce for the texture in the translucent stones. Between the two, there are major differences in feel; and the grey-ish translucent stones he has now is more to my liking. Over the last 18-24 months I've had a literal ton of Arks here for the purpose of comparing, testing, etc. Dan's products were included. Side by side, Dan's black ultra-fine did not prove to be finer than Dan's translucent, and it didn't feel as nice under the blade. Lapping the two side by side, the black ultra-fine lapped easier, telling me it's softer but I can't judge how much softer. After a lot of continued consideration, I have to say that I prefered honing on the translucent better, and that the translucent stone polished better also.

 

[duke762]

Nice write up! I've always wondered how the blacks could have such high SG's and still be black.

 

[David]

I’ve always wondered why a large number of translucent stones are full of fissures but you rarely see them in blacks.

 

[hobber]

Gamma, great info! Thank you.

 

[Biglo13]

I’ve always wondered why a large number of translucent stones are full of fissures but you rarely see them in blacks.

im dealing with a white ish trans with a flaw now....

 

[David]

im dealing with a white ish trans with a flaw now....

Got a pic?

 

[kelbro]

As is the case with any natural stone, there are so many variations. I've had blacks that worked better than trans that worked better than other blacks. I finally landed on a particular trans that suited my honing style and edge requirements. Funny thing is that a Dan's Hard came in second over several blacks. I kept the trans and the hard and sold off all of the blacks.

 

[LJS]

I rarely hear mention of the currently available norton translucent. Any particular reason? I have one and it is not a bad stone but don’t hear them mentioned much.

 

[Biglo13]

Got a pic?

 

[Biglo13]

Here is that spot. I can barely feel with thumb nail. Doesn’t seem to be scratching. Still needs some small high spots taken down/ lapping. 2x8 transluscent

 

[SliceOfLife]

David, I suspect the reason for that is that black material is far more abundant in this era than translucent material. So they compromise a lot more to get a decent size piece of translucent than they have to for Black

 

[RichieP]

Would Dan’s be the go to place to get an Ark stone?


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[Biglo13]

Would Dan’s be the go to place to get an Ark stone?


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dan’s, rh preyda, best sharpening supplies, natural whetstone, eBay, Amazon..... I under stand dan’s and RH preyda stones come well finished.