Rust on Steel types.

[Itsjun]

I own a couple of carbon knives.
It seems to me that white 1 and 2 rust more often.
I left my white2 knife unused for a week and rust begin to form.
Whereas my blue steel knives doesn't rust as often as my white steels.

Anyone can give some advice how to keep my white steels knives rust free longer?
I would like to use them as often as possible because they gives a very sharp edge compared to blue steels.
But this problem is preventing me from using them that often.
Some times it has patina but still rust.
Applying oil doesn't really help because I'm in a commercial kitchen.

Any expert can advise on this?

 

[slickmamba]

Why doesn't applying oil work? And yes, blue has a higher chromium content iirc, giving it slightly better rust prevention.

 

[Briochy]

Have you tried forcing patina? Honestly, can you actually tell the difference between the sharpness of white compared to blue steel? It should be very minute that you shouldn't be able to tell. Maybe it's just different heat treatments that caused the difference.

 

[HRC_64]

blue steels are designed to do exactly what you describe...hence the small amount of alloying elements

IMHO, the most important is put it away/set it aside FULLY dry,
and don't put it down on a clean board that is still damp
if you are gonna leave it for a while.

This can be hard to achieve in certain environments thata are
outside your control, unfortunately


white steels need to be kept drier, wiped cleaner, etc just that extra bit more...

 

[madelinez]

Blue steels contain small amounts of chromium, like 0.5% versus 12.5% for stainless but it's better than white's 0%. I've noticed the same thing, my friend's SC125 (similar to white) will rust if you look at it funny where as my blue knives you can leave wet for a few minutes without a disaster.

 

[Briochy]

I have a white#2 (albeit stainless clad) that has a great patina formed on the exposed edge and I have no problem leaving it slightly damp for 30 minutes while I finish eating my dinner. I'd argue that my slight negligence is what caused patina to forms so quickly and prevent an actual rusting.

 

[bahamaroot]

How is it stored? Can keep the blade wrapped in VCI paper when not in use unless it's in a block.

 

[Briochy]

Yeah, that's a good idea, wrapped in VCI paper (the same one as most blades are shipped with).

 

[M1k3]

I own a couple of carbon knives.
It seems to me that white 1 and 2 rust more often.
I left my white2 knife unused for a week and rust begin to form.
Whereas my blue steel knives doesn't rust as often as my white steels.

Anyone can give some advice how to keep my white steels knives rust free longer?
I would like to use them as often as possible because they gives a very sharp edge compared to blue steels.
But this problem is preventing me from using them that often.
Some times it has patina but still rust.
Applying oil doesn't really help because I'm in a commercial kitchen.

Any expert can advise on this?

When left for a week, oil it. Wash before use.

 

[Matus]

Not only Cr increases resistance to rusting/staining. Other alloy elements can have similar effect. With that said - 52100 (1.5% Cr) stains a in a very different way to purer carbon steel and does not make the jump from patina to rust quite as easily. Quick googling on the matter yields articles/info that suggests that W also improves corrosion resistance - and there is quite some of it in blue steels. But this would be something that @Larrin could give us a more relevant input on.

 

[madelinez]

Not only Cr increases resistance to rusting/staining. Other alloy elements can have similar effect. With that said - 52100 (1.5% Cr) stains a in a very different way to purer carbon steel and does not make the jump from patina to rust quite as easily. Quick googling on the matter yields articles/info that suggests that W also improves corrosion resistance - and there is quite some of it in blue steels. But this would be something that @Larrin could give us a more relevant input on.

I didn't realise tungsten helps with corrosion resistance, makes me happy though since I love tungsten carbon steels. Blue 2, Super Blue, 1.2442, 1.2562, V-Toku 2, etc. They all take a super nice toothy edge that lasts forever at the slight expense of peak sharpness.

 

[Michi]

Why doesn't applying oil work?

Oil keeps air away from the blade surface. No oxygen, no rust.

 

[slickmamba]

Oil keeps air away from the blade surface. No oxygen, no rust.

I know why oiling works. I was asking the poster why he says oiling doesn’t work

 

[Michi]

I know why oiling works. I was asking the poster why he says oiling doesn’t work

Ah, sorry, misunderstanding on my part.

 

[Itsjun]

I know why oiling works. I was asking the poster why he says oiling doesn’t work

If I'm gonna use it at my work place daily or regularly then every time I got to apply and wash it when using.

 

[HRC_64]

If I'm gonna use it at my work place daily or regularly then every time I got to apply and wash it when using.

FYI you can use olive oil with no problems for overnight storage or even weekly use.

The recommendations for non-food grade oils are for long-term storage, typically like 3+ months which if you are a maker/retailer would be quite relevant. Alxo, also to collectors who would be storing more knives that could be used in a normal time period, and or for longer term collectors dealing with issues of years at a time where items will be in a box.

Note that VCI paper is actaually better than oil for alot of the above uses, hence its widespread adoption by retailers and manufacturers managing inventory/supply chain issues. At least this is my understanding.

TLDR food grade oils are avoided due to high cost and undesirabiliy for long term use. If you workin a kitchen and food grade oils are freely available and your schedule requires frequent use, they may be a good option to consider (hack).

 

[slickmamba]

Ah, sorry, misunderstanding on my part.

Haha no worries, we’ve all been there.

If I'm gonna use it at my work place daily or regularly then every time I got to apply and wash it when using.

Ahh I see, but for the 1 week being unused, oil should be more than fine. As for daily use, wiping more often, more developing a strong patina would help. Do you have fully reactive white steel knives, or stainless clad?

 

[inferno]

1095/whites/all unalloyed carbons are usually rustbuckets comparatively. i only have 1 knife in white and im not getting another anytime soon.
I only buy blue or better if buying carbon. because it rusts much slower, stays sharp much longer, and in my house, gets sharper.

i oil the kurouchi finish with tung oil. it hardens and then its rustproof. you cant wash it off or dry it off. this has worked really well.

 

[Larrin]

Tungsten helps with corrosion resistance in stainless steels but I don’t know about in low alloy steel. Personally I don’t worry about the subtle differences between low alloy steels since the corrosion resistance of all of them is bad.

 

[inferno]

All low alloy carbons are equal. but some are more equal than others...

 

[Larrin]

All low alloy carbons are equal. but some are more equal than others...

I would guess surface finish and the foods it happened to be used on are more important than the steel type in most cases. But I'm not going to have much impact on "reactivity" folklore I am sure.

 

[Itsjun]

Haha no worries, we’ve all been there.



Ahh I see, but for the 1 week being unused, oil should be more than fine. As for daily use, wiping more often, more developing a strong patina would help. Do you have fully reactive white steel knives, or stainless clad?

I believe it's not cladded.
Even when sharpening, it'll start to turn brownish if it's intact with water too long when sharpening.

 

[Nemo]

I believe it's not cladded.
Even when sharpening, it'll start to turn brownish if it's intact with water too long when sharpening.

Never had this problem. Are you a very meticulous sharpener? Do you have water with a lot of electrolytes or acid?

 

[HRC_64]

Never had this problem. Are you a very meticulous sharpener? Do you have water with a lot of electrolytes or acid?

IIRC many japanese knife sharpeners use rust-inhibitors in their pond water,
it looks like green anti-freeze or something similar when seen on you-tube videos.

 

[Beau Nidle]

This thread makes me feel like I lucked out with my one White #2 knife. Had it 9 years and no issues with rust. The patina is solid grey in places now.

 

[inferno]

i have noticed that my low alloyed carbon knives can sometime start rusting during when i'm sharpening them. or putting a finish on the sides. this happens it like 2-5 minutes on my coticules somehow. lots of small brown spots all over.

so i put a dash of baking powder in the sharpening water. and then 0 rust!

 

[playero]

Try using food grade wax