Stainless knife appears to be staining

[Sparhawk]

I recently purchased a nakagawa ginsan bunka with stainless cladding from home butcher. I've noticed after using it that the knife appears to be staining with use from cutting bell peppers. Is this laq uer I need to remove? I also noticed that the engraving was very red when it arrived but that shouldn't be rust correct?

Sorry I'm new to all this but want to make sure I'm not making any major mistakes.

 

[jedy617]

That might be some left over lacquer...or potentially it could be some patina/rust. Stainless is just as it sounds...stain-less. Not stainproof. They can definitely get some patina or even rust if left dirty for quite awhile.

 

[HumbleHomeCook]

The color in the kanji might just be remnants from the tools used to cut it.

 

[M1k3]

That is probably rust in the engraving. Leftover metal bits from the tool used to inscribe the blade. You can pour boiling hot water over it until it turns black. It'll be stable from then on.

 

[Sparhawk]

That might be some left over lacquer...or potentially it could be some patina/rust. Stainless is just as it sounds...stain-less. Not stainproof. They can definitely get some patina or even rust if left dirty for quite awhile.

I've been wiping it after use so didn't think it would stain that fast being stainless clad ginsan.

From what I've read to remove the lawyer I would just go over it with acetone.

Is it better to remove the rust or go over with hot water as stated below? What would be the best method for the kanji.

 

[Dan-]

Use a toothbrush and some toothpaste

 

[M1k3]

I've been wiping it after use so didn't think it would stain that fast being stainless clad ginsan.

From what I've read to remove the lawyer I would just go over it with acetone.

Is it better to remove the rust or go over with hot water as stated below? What would be the best method for the kanji.

I'd remove the lacquer.
You can remove the rust. But unless you're able to get all the bits out causing the rust, it'll come back eventually.

 

[dehory]

I recently purchased a nakagawa ginsan bunka with stainless cladding from home butcher. I've noticed after using it that the knife appears to be staining with use from cutting bell peppers.

IME Nakagawa stainless is very unreactive — my Mercer and German beater stainless knives stain more easily than my Nakagawa ginsan’s stainless cladding. If removing the lacquer doesn’t resolve the issue, I’d reach out to Phil at Homebutcher to see what he says.

 

[thebradleycrew]

Just from looking at your photo, it looks like a protective layer/lacquer on there. I'm referring to how on the core steel down at the bottom of the blade road you see some brighter core steel versus the darker core steel before the stainless cladding line. That looks like a classic lacquer type of finish were cutting with it starts to wear it off at the edge first, working it's way towards the spine. I'd (1.) take off what appears to be the lacquer with acetone and a soft/lint free type of rag. This takes longer than you'd think a lot of the time but just be gentle and be sure to spend the time on it making sure you get it all off. Then 2. give the whole blade a good clean with hot water and soap and soft brush/sponge. Then 3. I'd use a toothbrush and soap to work on the kanji and just see if that changes the red you are seeing which is hard for me to discern from the pictures. After that, then I'd see where you stand and decide next steps!

 

[captaincaed]

I'd default to the advice above to start - get the lacquer cleaned off and see how things look.

Worth noting, that "stainless" is a marketing term, not a statement of fact. Various levels of neglect will in fact rust a "stainless" steel.

Some saltwater testing from CPM MagnaCut - The Next Breakthrough in Knife Steel - Knife Steel Nerds, under the section "Corrosion Resistance".
The author is promoting his own steel in the article, but it's still a pretty basic test that holds variables constant across the test pieces.

Considering composition alone (and realizing that heat treatment will affect "how stainless is this steel"), your ginsan will probably perform similar to AEB-L.

http://zknives.com/knives/steels/steelgraph.php?nm=Ginsan,AEB-L&ni=5008,878&hrn=1&gm=0

 

[MSicardCutlery]

More carbon means that more chrome is taken up by the carbon for carbide formation. That's why ZDP-189, with 20% chrome and 3% C has lower corrosion resistance than D2 (1.5% C and 12% Cr), which is semi-stainless. It's probable that AEB-L has the greater corrosion resistance of the two.

The Ginsan composition is a lot like 154cm if the Molybdenum was omitted, and Mo enhances corrosion resistance.

Larrin has published equations on KSN that are for predicting corrosion resistance based on composition.