vinegar patina on bilton

[jefptw]

This summer I bought three biltons, two with wood handles and one with a horn handle. My son has one of the wood-handled ones and I kept the other one for myself. My daughter got the horn handled one. After returning to Taiwan and to the forum I read several discussions on the forum about patinas showing up after cutting various materials, usually foods. It sparked my curiosity and I decided to try and see what kind of a patina vinegar would leave on the bilton I so conveniently kept for myself. Below are the results.

After washing the blade, I filled a jar with apple cider vinegar and put the knife into it. The vinegar came right up to the handle. I left it in the vinegar overnight and until about noon the next day, a total of about 14 hours. The second picture shows both biltons just after treatment. The last shows the tip of the blade after treatment against a black background. It came out a fairly dark grey. (The next day I did a Wade and Butcher straight razor and it came out BLACK.) You can see the contrast with the metal near the edge. I like it, although I still want to keep some of my khuks in their mirror-finished glory. Also, the blade with the heavy patina does seem to hold oil better than my shiny blades.


James

 

[munk]

Is there any way to do this and come out with nice looking colors instead of grey? My Tarwar is grey. I could get blue in spots, and yellow, but not consistantly.
How do you master refinishers do this?


I like my grey Tarwar.

munk

 

[richardallen]

I think you can get blue by cutting garlic. Not sure how you'd get an even garlic finish though....

Keno

 

[Josh Feltman]

Looks good! I prefer a nice patina to a mirror finish on most khuks.

munk--I've never been able to get colors consistently.

As for the garlic finish, they sell minced garlic at the store.

 

[munk]

I cut meat with the munk cleaver and that left half the blade blue. The tarwar is already grey, so I'd have to take that off before going forward.



munk

 

[Dave Rishar]

Got sort of the same thing with the Jure -- chopping frozen meat turned the blade blue and purple. The hardened area is visible.

Neat how different foods produce different colors, huh?

 

[Kevin the grey]

Jefptw ? I am just wondering what effect would be possible on stainless steel ?

I have a couple of stainless blades I would like to change the look of . They are not expensive so I could experiment a bit . I would like to get them to look like carbon steel or at least not look so new .

 

[Sylvrfalcn]

(The next day I did a Wade and Butcher straight razor and it came out BLACK.)

Noooooooooooooooo

Sarge

Uh, say Kevin, trying to get an etch/patina on stainless? Unless you've got access to a mad scientist, I'd bet some nickel and some chromium that that particular dog won't hunt.

 

[Kevin the grey]

Yep its kinda like loading up blanks for grizzly .

 

[jefptw]

Noooooooooooooooo

Sarge

Sorry Sarge,

I should have considered your feelings before posting that. It's interesting, though. After treating/defacing/desecrating the razor, I seem to be able to get a better edge on it. I think the vinegar actually removed some metal and made the blade slightly thinner in the hollow grind. I wiped it and washed it several times after removing it from the vinegar, and each time the some black stayed on the sponge/towel. And the tone when thumb testing the edge has definitely changed.

But why is it that the W&B got so much darker. Would that have to do with higher carbon content?

I guess the next step would be to torture test some MetalGlo to see if it can undo my abuse. But I haven't been able to find any of that over here, so to heck with it.

James

 

[munk]

Maybe after giving the blade a patina, you are more familiar with it, or can see the edge better to sharpen, but it's a mystery if a patina improved the edge of a blade.


munk

 

[jefptw]

Maybe after giving the blade a patina, you are more familiar with it, or can see the edge better to sharpen, but it's a mystery if a patina improved the edge of a blade.


munk

Like I said, I think the vinegar actually removed some metal. If that is the case, the blade should be slightly thinner. So it wouldn't be the patina, per se. I do know that the tone it makes when stropped or when scraped across my thumb has changed.

James

 

[munk]

It's hard for me to believe it could remove that much metal, but I'm not a knife guy, so I don't know.


munk

 

[Kevin the grey]

Like I said, I think the vinegar actually removed some metal. If that is the case, the blade should be slightly thinner. So it wouldn't be the patina, per se. I do know that the tone it makes when stropped or when scraped across my thumb has changed.

James

I do not doubt that if the metal were thinner the tone would change . It may also be with the patina on the metal that the tone would change . Anything you put on the outside of something that vibrates will change its tone as well . The only test I could see would be to clean the metal , test the tone , put on a patina , test the tone , reclean the metal and retest the tone . Or you could just enjoy the change .

 

[Sylvrfalcn]

If anybody thinks soaking a straight razor in a mild acid solution can make it any sharper or shave any better, they need to pass me whatever they're smoking so I can take a hit. No way a simple soak in vinegar can significantly alter the physical characteristics of a carbon steel blade. Sorry guys, it don't work that way with steel. Subsequent sharpening/stropping following the etching is more likely the contributing factor to any change in performance. I don't care if you've got "magic vinegar", it only turns the blade dark as a result of surface oxidation, it doesn't reshape it or change it's molecular structure one bit. It would, perhaps, be nice if it did, but it don't. But don't take my word for it, talk to any metallurgist you like, just make sure they set their coffee down before you broach your hypothesis.
Worn metal cutting files can be slightly "refreshed" by giving them a bath in Sulphuric Acid, but DO NOT attempt etching any of your blades in that stuff. If you do, you're on your own hoss.

Sarge

 

[Kevin the grey]

What Sarge said rang a bell . O:K: so maybe it was only a hollow sound from my noggin .

If this patina is the end result of an oxidation process . Perhaps the byproduct of this is an oxide buffing/stropping compound . (I can see the eyebrows raising now . L:O:L)

Anyway maybe this patina aids in getting a keener edge by means of the old strop .

 

[jefptw]

... I don't care if you've got "magic vinegar", it only turns the blade dark as a result of surface oxidation, it doesn't reshape it or change it's molecular structure one bit. It would, perhaps, be nice if it did, but it don't. ...

Sarge

After reading your reply, my curiosity screamed louder than my better judgement, so I gave the ol' razor another soak. The final word is that the vinegar does in fact remove metal. It doesn't even have to be "magic" vinegar -- the plain old apple cider type will do. Too bad for the razor.

Curiosity killed the cat.

But satisfaction brought him back.

James

 

[Kevin the grey]

All I can say is aughhhhh !

 

[Sylvrfalcn]

Point made, but at the cost of a good razor. I kind of already knew that if you leave a ferrous metal in a corrosive medium long enough, that it would, in fact, corrode. Didn't get any sharper, but it did corrode. As far as the previous hypothesis, it stands to reason that if the acid were removing enough metal as to actually thin the blade, it would also be attacking the most fragile part of the blade, it's cutting edge, making it noticeably duller. Your photo illustrates that nicely, thanks for sharing.

Sarge

 

[jefptw]

...it stands to reason that if the acid were removing enough metal as to actually thin the blade, it would also be attacking the most fragile part of the blade, it's cutting edge, making it noticeably duller. ...

Sarge

I agree. It certainly attacked and thinned the whole blade. Perhaps I should have said that it made it easier for me to get a really keen edge. (I did hone and strop it after taking it after the vinegar the first time.) My fault for ambiguous wording.

James