# How to fix pitting in vintage knives?



## Geo87 (Mar 26, 2014)

Hey all. 

Fixing up a 12" vintage dexter carbon butchers knife ( curtesy of son) 

I've removed the old patina & most of the scratches with sandpaper but there are a few stubborn black spots that won't come off. 
I'm guessing this is pitting? 

From what I've read this is "extremely localised corrosion leading to small holes in metal" 
Anyone have any advice on what I should do about it? 

Here's a bad photo... What I'm talking about are the spots near the heel


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## ecchef (Mar 26, 2014)

Battle scars. I'd just leave it. Adds character.


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## Dave Martell (Mar 26, 2014)

The two choices are to either sand them away or to neutralize the active rust to prevent further corrosion.


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## Asteger (Mar 26, 2014)

Dave Martell said:


> The two choices are to either sand them away or to neutralize the active rust to prevent further corrosion.



Is there a way of 'neutralizing' pits aside from griding at them? Not that I'd like it, but a chemical way perhaps?


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## James (Mar 26, 2014)

never tried it, but I've read somewhere that black strap molasses can be used for rust.


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## ecchef (Mar 26, 2014)

Naval Jelly will work. Leaves a dark, dull grey finish.


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## Geo87 (Mar 26, 2014)

Thanks guys, 

I'm all for battle scars but I'm just concerned about further corrosion. I think it would take a great deal of hand sanding to get rid of them...
I'd be interested in trying a chemical to neutralise it as Dave said, as long as there aren't any side effects? 

I couldn't find any navel jelly for sale locally (brisbane) 
But a search revealed it is phosphoric acid based. I can buy "sepitone rust converter" from super cheap auto which is also a concentrated phosphoric acid based product. 
It's description is: "Converts rust (iron oxide to a non-reative white powder coating (iron phosphate)"

Any thoughts?


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## Keith Sinclair (Mar 26, 2014)

Geo When you sand off the surface rust if its been there a while you will get pitting or those black spots.Pretty common on old carbons.You are right hard to hand sand out.Just keep the blade oiled when not in use.


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## Mute-on (Mar 26, 2014)

Mate, just get some Ranex from Bunnings and dab a bit on the actual rust spots with a cotton bud. It will neutralise the rust and just turn it black.

Cheers,

J


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## MAS4T0 (Mar 26, 2014)

I'm not seeing the picture, but generally if the Iron Oxide isn't orange/ brown, it is stable and won't cause any further problems. 

There are different oxides of iron. Rust is Iron(III) Oxide. I would assume that the pitting is a stable oxide.


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## Geo87 (Mar 27, 2014)

Alright well as the spots are black it sounds like it's alright to leave them as they are most likely stable. Good to know. I keep all carbons regularly oiled anyway so no problem there. 
Thanks everyone for your input.


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## Asteger (Mar 27, 2014)

MAS4T0 said:


> .. generally if the Iron Oxide isn't orange/ brown, it is stable and won't cause any further problems. There are different oxides of iron. Rust is Iron(III) Oxide. I would assume that the pitting is a stable oxide.



That's the kind of expertise we like! :goodpost:


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