# Erasing the patina



## Don Nguyen (Sep 1, 2012)

What's your method?


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## stevenStefano (Sep 1, 2012)

Barkeeper's Friend


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## Chifunda (Sep 1, 2012)

I don't erase...I embrace. :happymug:


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## JMJones (Sep 1, 2012)

If I get actual rust, I keep a little peice of 600 grit sand paper near the sink and give the blade a quick scrub.


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## Benuser (Sep 1, 2012)

ScotchBrite


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## SameGuy (Sep 1, 2012)

I find green ScotchBrite does OK at removing the top layers, but without a chemical to mildly etch it out it can only do so much. BKF is a gentle-enough acid, with a gentle-enough abrasive to do a wonderful job.


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## RRLOVER (Sep 1, 2012)

BKF and then some Flitz.


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## Benuser (Sep 1, 2012)

The ScotchBrite I use is the coarse one, color mauve/brown. I must agree not the deepest patina is being removed, but have never wanted to do so.


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## SpikeC (Sep 1, 2012)

Concentrated nitric acid. It'll get that nasty patina ALL the way off!


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## chinacats (Sep 2, 2012)

After the acid, you may want to neutralize. Baking Soda should do the trick...


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## DwarvenChef (Sep 2, 2012)

Ack, sputter choke.... your killing me


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## Twistington (Sep 2, 2012)

Tormek PA-70 honing compound on a piece of cloth.


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## Birnando (Sep 2, 2012)

I use some Autosol or Flitz on a rag if I want to remove/reduce patina.


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## Don Nguyen (Sep 2, 2012)

Thanks for all the suggestions everyone!

I heard that some stuff can actually scratch the blade or mess up the finish somehow. Which ones should I be aware of, and any other tips as to not cause myself grief?


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## Cutty Sharp (Sep 2, 2012)

I just tried using _Steel Glo_. Not much patina on my knives, but had some light rusty bits and this did very well. Bought this a few years ago in Malaysia and forgot about it, but obviously still works. It's a US product so should be available for you. Also it claims to be non-toxic which is a plus.

http://www.agelong.com/v/vspfiles/photos/03655-2T.jpg


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## Pensacola Tiger (Sep 2, 2012)

Don Nguyen said:


> Thanks for all the suggestions everyone!
> 
> I heard that some stuff can actually scratch the blade or mess up the finish somehow. Which ones should I be aware of, and any other tips as to not cause myself grief?



I would start with BKF on the end of a wine cork or a metal polish like Flitz, Metal-Glo or Nevr-Dull wadding. ScotchBrite, both the green and brown, may put fine scratches on a blade, at least in my experience.


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## Cutty Sharp (Sep 2, 2012)

Not any of my ScotchBrites!


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## Pensacola Tiger (Sep 2, 2012)

Patina cleaning test

I was curious enough to do a short test of the three methods that were suggested: BKF with a cork, BKF with a ScotchBrite pad and a metal polish, in this case Metal-Glo.

















The sacrificial lamb was a Harner O1 cleaver. This is how it looked pre-test:






I soaked a paper towel in vinegar and laid it on the blade for five minutes. Instant patina.






Then I cleaned three swaths, from top to bottom, Metal-Glo on a paper towel; BKF on a wine cork; BKF with a new ScotchBrite pad.
















I was a bit surprised to see that the metal polish did the best job. The fine scratch pattern that the ScotchBrite pad left is easily seen. 

Rick


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## Benuser (Sep 2, 2012)

Nice pix!


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## Don Nguyen (Sep 2, 2012)

Rick, this is more than I could ever ask for in a reply. Thanks so much!

Certainly the scratches are very visible. I was always hesitant using scotch brites, because if makers use them to _create_ a finish, than using one to clean up a knife would certainly alter the finish, wouldn't it? Maybe it's a certain type of scotch brite, or technique, or something.

That metal polish looks fantastic, and I'll have to go get some.


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## sachem allison (Sep 2, 2012)

I find a good tooth paste works well, make sure it's a paste and not gel. a smokers toothpaste has a little extra grit. put a little bit on a towels and rub away.


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## mhenry (Sep 2, 2012)

+1 I thought I was the only one using toothpaste works great



sachem allison said:


> I find a good tooth paste works well, make sure it's a paste and not gel. a smokers toothpaste has a little extra grit. put a little bit on a towels and rub away.


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## Pensacola Tiger (Sep 2, 2012)

But doesn't using toothpaste on a knife give it a tendency to bite your hand?


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## VoodooMajik (Sep 2, 2012)

I actually use plane whit vinager if I get small rust spots. As far as patina goes I haven't removed one, patina on my Yoshihiro is getting pretty deep and not so pleasing. Never though of tooth paste. I was thinking i would need a finger stone to repolish things. Thanks for this thread.


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## sachem allison (Sep 2, 2012)

Pensacola Tiger said:


> But doesn't using toothpaste on a knife give it a tendency to bite your hand?



i like steel with a good bite.


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## knyfeknerd (Sep 3, 2012)

This is a great thread. Thanks for taking it the extra mile Rick.
I'm on the BKF/Flitz tip. I find the Scotch-Brite too abrasive, no matter the grit. It even leaves tiny scratches on my stainless Henckels. Also, a little Chromium Oxide on the buffing wheel(gotta be careful though) will shine it up like a champ!


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## Cutty Sharp (Sep 3, 2012)

Pensacola Tiger (or anyone else with scratches) - now that you have those ScotchBrite scratches on your blade, what is your method of removing them - ie. polishing off the scratches?


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## SameGuy (Sep 3, 2012)

knyfeknerd said:


> I find the Scotch-Brite too abrasive, no matter the grit. It even leaves tiny scratches on my stainless Henckels.


Yep. I use the green ScotchBrite side of regular kitchen sponges on my extremely-reactive Sab paring knife, which is well pitted and scratched anyway. After hulling just a couple of pints of strawberries it will take on a deep -- almost black -- patch across the middle, which is less than pleasing to the eye.


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## Pensacola Tiger (Sep 3, 2012)

Cutty Sharp said:


> Pensacola Tiger (or anyone else with scratches) - now that you have those ScotchBrite scratches on your blade, what is your method of removing them - ie. polishing off the scratches?



I don't know about anyone else, but hand-rubbing with wet/dry 3M paper backed with something with 'give' is the way I go. Don't use a hard block, because it won't conform to the surface and you'll just polish the high spots. For scratches like those I put on the Harner, I'll start with 400, then move to 800 and finish some MetalGlo.


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## Pensacola Tiger (Sep 3, 2012)

I had some time this morning, so I tried toothpaste on the stripe of patina between the area cleaned at the top with Metal-Glo and the area cleaned with BKF and a cork. Toothpaste may work on light patina, but it didn't do a great job this time. YMMV.


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## Lefty (Sep 3, 2012)

In Canada, we're limited (I can't find Flitz ANYWHERE!!!). For my cleanups, I use wet/dry, but for the pitting, would nevrdull, BKF, or Autosol work? If so, which is best?

Awesome thread!


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## Cutty Sharp (Sep 3, 2012)

This thread is giving me some idea of the next consolidated shipment I'll have sent from the US, so long as customs doesn't determine some things to be hazardous chemicals!


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## SpikeC (Sep 3, 2012)

Has anyone else tried baking soda?


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## dmccurtis (Sep 3, 2012)

Home Hardware has Flitz.



Lefty said:


> In Canada, we're limited (I can't find Flitz ANYWHERE!!!). For my cleanups, I use wet/dry, but for the pitting, would nevrdull, BKF, or Autosol work? If so, which is best?
> 
> Awesome thread!


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## Cutty Sharp (Sep 3, 2012)

SpikeC said:


> Has anyone else tried baking soda?



I have. Arm & Hammer. Didn't really do a thing.


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## wsfarrell (Sep 4, 2012)

If your blade has a factory finish that runs from spine to edge--Sab, Henckels, Wusthof, many Konosukes, Devin Thomas (non-damascus), TKC, many many others--you can restore that finish perfectly with a scotchbrite belt on a belt grinder. This will remove all patina that isn't actual pitting, and is the way many knifemakers finish their blades. 

If the finish on your knife runs from heel to tip, this won't work. In that case, wet/dry sandpaper on a hard rubber block will work. I've used worn 220, lubed with water/Dawn, to restore the finish on several Shigs and Watanabes to better than factory--in my opinion, at least. Pic below shows a Shigefusa 240 kasumi gyuto that developed some corrosion while out for rehandling:







And this is how it looked after a minute with 220 (sorry about the lighting--fluorescents in second photo):






For polish, I really like Mother's Mag. Mentioning it because I didn't see it in this thread.


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## [email protected] (Sep 4, 2012)

kurenza-----! and daikon!


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## [email protected] (Sep 4, 2012)

yes, I'm sorry but I don't know how to spell this Japanese white powder thing for polishing up steel.


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## shankster (Sep 4, 2012)

[email protected] said:


> yes, I'm sorry but I don't know how to spell this Japanese white powder thing for polishing up steel.



Not sure if this is what you mean..you can see it at about 4 minutes

http://marthastewart.com/914242/nobu-knife-sharpening-techniques


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## GlassEye (Sep 4, 2012)

&#12463;&#12524;&#12531;&#12470;&#12288;is cleanser I believe, which would be an abrasive cleaner like Comet, Barkeepers Friend, etc.


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## Don Nguyen (Sep 8, 2012)

I got some Metal Glo (United Cutlery brand) and tried it out on an old knife really quick.

Took off the heavy, dark patina really fast. There was still this underlying patina that looked subtly like water stains or something similar. Maybe I just gotta put more elbow grease in it, we will see.


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## Cutty Sharp (Sep 8, 2012)

Though I am no metallurgist I think sometimes you'll get spots where the reactions forming 'patina' are much deeper and have put down roots, and maybe are not so easy to remove if at all, unless some grinding occurs. I've long since polished away the colour on my practice knife, a santoku, but there are still hints at the swirls from my erstwhile forced mustard patina. I've even scrubbed the blade with some quite abrasive stuff and it refuses to go.


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## Don Nguyen (Sep 8, 2012)

It probably depends heavily on how the blade is finished. A mirror polished would probably have less of such patina than one finished at 300 grit, I'm guessing?

The metal glo works great though.


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## andoniminev (Sep 10, 2012)

I use japanese natural fingerstones. Depending on the patina sometimes i use a combination of different stones. Drnaka has a nice post about that where he tests different methods. I have never tried with any powders because i get amazing results with natural fingerstones.


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