How to darken or patina O1

R

Rminton

Joined
Feb 4, 2017
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im making a knife for a friend who wants a darker finish. My initial thought is vinegar.

I have a few pieces of O1 scrap since I do stock removal. I'm using these as a test piece. I left a piece sitting in vinegar for hours with next to no results. I tried using heated almost boiling vinegar and almost nothing. I even let one sit in vinegar in the hot 103 degree St. Louis sun for hours. Still nothing.

I was using rice vinegar, as I had it on hand. Is that why? Does anyone have any other tips?
 
If heated vinegar (at least) did nothing, something's not right. Either the steel isn't what you think it is (behaves like stainless, as described), or it's coated with something. I haven't tried any O1, but others here who've posted about it have indicated it patinates pretty easily.

Might sand or grind a portion of the steel to expose some fresh (unoxidized) surface, and try again. Might also try some different vinegar (fresh/new), such as simple white vinegar. Maybe the rice vinegar has gone 'flat' or otherwise lost it's acidity. Even then, in a heated solution of vinegar or even just hot water, it likely should've darkened at least a little bit.


David
 
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I have a piece of 01 annealed stock that has been in my basement for about 2 years (really taking my time making this knife). I have not noticed it darkening much. I wonder if it oxidizes more after it has been heat treated? Have you heat treated your knife yet?
 
It might be bad vinegar. I didn't notice many bubbles and it did stain / patina with mustard. I'll also try sanding and redoing. Is there anything in particular you use to remove any oils from the steel before you force the patina?
 
I have a Ratmandu that came coated. I stripped the coating, went through various levels of sandpaper. I then wrapped a couple of layers of paper towel around the blade and coated with apple cider vinegar. Then I placed it in a stainless steel drywall pan for 5 days with syran wrap? After 5 days, I gave her a bath in the sink with dish lotion and a paper towel and out in the sun to dry.
I now have a dark patina to protect against rust. You can always redo at any point in time.
 
My favorite on 01 is coffee...it does not end up as dark as vinegar, but gives a pretty uniform and durable gray patina like those you find on old kitchen knives, etc. Once it is there, there are no more off tastes / smells when cutting various fruits and veggies, which is a big plus. At one, maybe two stirs of a French press per day it does take some time though...
 

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Sturubu said:
My favorite on 01 is coffee...it does not end up as dark as vinegar, but gives a pretty uniform and durable gray patina like those you find on old kitchen knives, etc. Once it is there, there are no more off tastes / smells when cutting various fruits and veggies, which is a big plus. At one, maybe two stirs of a French press per day it does take some time though...
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Try some intelligentsia maybe, it gets very acidic as it cools. Nice JK knife!
 
I cleaned this o1 blade with alcohol then soaked it in warm white vinegar for 20 minutes.
b2ab5W1.jpg
 
Kootaga13 said:
I like that idea Sturubu. Have you ever stood a knife up in a glass of coffee overnight?
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I have not tried letting one sit. I just give the pot a stir, and let the coffee and oils dry on the blade. It definitely takes some time, but takes minimal effort. I may try steeping one and see if it speeds the process up.

jbarsquat said:
Try some intelligentsia maybe, it gets very acidic as it cools. Nice JK knife!
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Thanks! I've treated almost all my JK knives to this - Jonh's 01 seems to really like coffee...I will need to find some intellegentsia for sure, it sounds like my kind of brew.
 
Not to turn this into a coffee thread, but their black cat espresso is some of the best coffee I've ever tried. I have made it in a French press, aeropress, and my Chemex pour over. Aeropress is the best result but requires the most work! I have a kephart coming in a couple weeks from John and will try that right away
Edit to add using the chemex with a metal filter will leave the most oils in the brew so I will try that method and report back
 
Rminton said:
im making a knife for a friend who wants a darker finish. My initial thought is vinegar.

I have a few pieces of O1 scrap since I do stock removal. I'm using these as a test piece. I left a piece sitting in vinegar for hours with next to no results. I tried using heated almost boiling vinegar and almost nothing. I even let one sit in vinegar in the hot 103 degree St. Louis sun for hours. Still nothing.

I was using rice vinegar, as I had it on hand. Is that why? Does anyone have any other tips?
Click to expand...

Try this: www.rustblue.com
Beautiful black/blue with American or Swiss Formulas.
 
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