Rust on Steel types.

Discussion in 'Kitchen Knife Knowledge' started by Itsjun, Nov 28, 2019.

Help Support Kitchen Knife Forums by donating:

  1. Nov 28, 2019 #1

    Itsjun

    Itsjun

    Itsjun

    Active Member

    Joined:
    Feb 28, 2019
    Messages:
    40
    Location:
    Singapore
    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?
     
  2. Nov 28, 2019 #2

    slickmamba

    slickmamba

    slickmamba

    Senior Member

    Joined:
    Apr 5, 2018
    Messages:
    363
    Why doesn't applying oil work? And yes, blue has a higher chromium content iirc, giving it slightly better rust prevention.
     
  3. Nov 28, 2019 #3

    Briochy

    Briochy

    Briochy

    Well-Known Member

    Joined:
    Sep 29, 2019
    Messages:
    56
    Location:
    Australia
    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.
     
  4. Nov 28, 2019 #4

    HRC_64

    HRC_64

    HRC_64

    Senior Member

    Joined:
    Aug 9, 2017
    Messages:
    2,501
    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...
     
  5. Nov 28, 2019 #5

    madelinez

    madelinez

    madelinez

    Well-Known Member

    Joined:
    Jun 6, 2018
    Messages:
    190
    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.
     
  6. Nov 28, 2019 #6

    Briochy

    Briochy

    Briochy

    Well-Known Member

    Joined:
    Sep 29, 2019
    Messages:
    56
    Location:
    Australia
    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.
     
  7. Nov 28, 2019 #7

    bahamaroot

    bahamaroot

    bahamaroot

    Senior Member

    Joined:
    Jan 14, 2013
    Messages:
    1,337
    How is it stored? Can keep the blade wrapped in VCI paper when not in use unless it's in a block.
     
    Last edited: Nov 28, 2019
  8. Nov 28, 2019 #8

    Briochy

    Briochy

    Briochy

    Well-Known Member

    Joined:
    Sep 29, 2019
    Messages:
    56
    Location:
    Australia
    Yeah, that's a good idea, wrapped in VCI paper (the same one as most blades are shipped with).
     
  9. Nov 28, 2019 #9

    M1k3

    M1k3

    M1k3

    Senior Member

    Joined:
    Jul 28, 2018
    Messages:
    746
    When left for a week, oil it. Wash before use.
     
    adam92 likes this.
  10. Nov 28, 2019 #10
    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 likes this.
  11. Nov 28, 2019 #11

    madelinez

    madelinez

    madelinez

    Well-Known Member

    Joined:
    Jun 6, 2018
    Messages:
    190
    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.
     
  12. Nov 28, 2019 #12

    Michi

    Michi

    Michi

    Supporting Member

    Joined:
    Jan 13, 2019
    Messages:
    1,484
    Location:
    Brisbane, Australia
    Oil keeps air away from the blade surface. No oxygen, no rust.
     
  13. Nov 28, 2019 #13

    slickmamba

    slickmamba

    slickmamba

    Senior Member

    Joined:
    Apr 5, 2018
    Messages:
    363
    I know why oiling works. I was asking the poster why he says oiling doesn’t work
     
    M1k3 likes this.
  14. Nov 28, 2019 #14

    Michi

    Michi

    Michi

    Supporting Member

    Joined:
    Jan 13, 2019
    Messages:
    1,484
    Location:
    Brisbane, Australia
    Ah, sorry, misunderstanding on my part.
     
  15. Nov 28, 2019 #15

    Itsjun

    Itsjun

    Itsjun

    Active Member

    Joined:
    Feb 28, 2019
    Messages:
    40
    Location:
    Singapore
    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.
     
  16. Nov 28, 2019 #16

    HRC_64

    HRC_64

    HRC_64

    Senior Member

    Joined:
    Aug 9, 2017
    Messages:
    2,501
    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).
     
    M1k3 likes this.
  17. Nov 28, 2019 #17

    slickmamba

    slickmamba

    slickmamba

    Senior Member

    Joined:
    Apr 5, 2018
    Messages:
    363
    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?
     
  18. Nov 28, 2019 #18

    inferno

    inferno

    inferno

    Senior Member

    Joined:
    Jan 11, 2018
    Messages:
    1,581
    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.
     
  19. Nov 28, 2019 #19

    Larrin

    Larrin

    Larrin

    Senior Member

    Joined:
    Mar 13, 2011
    Messages:
    573
    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.
     
  20. Nov 28, 2019 #20

    inferno

    inferno

    inferno

    Senior Member

    Joined:
    Jan 11, 2018
    Messages:
    1,581
    All low alloy carbons are equal. but some are more equal than others...
     
  21. Nov 29, 2019 #21

    Larrin

    Larrin

    Larrin

    Senior Member

    Joined:
    Mar 13, 2011
    Messages:
    573
    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.
     
    Benuser likes this.
  22. Nov 29, 2019 #22

    Itsjun

    Itsjun

    Itsjun

    Active Member

    Joined:
    Feb 28, 2019
    Messages:
    40
    Location:
    Singapore
    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.
     
  23. Nov 29, 2019 #23

    Nemo

    Nemo

    Nemo

    Staff Member Global Moderators

    Joined:
    Oct 16, 2016
    Messages:
    4,235
    Location:
    Southern NSW (Aus)
    Never had this problem. Are you a very meticulous sharpener? Do you have water with a lot of electrolytes or acid?
     
  24. Nov 29, 2019 #24

    HRC_64

    HRC_64

    HRC_64

    Senior Member

    Joined:
    Aug 9, 2017
    Messages:
    2,501
    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.
     
  25. Dec 4, 2019 #25

    Beau Nidle

    Beau Nidle

    Beau Nidle

    Hobbyist Craftsman

    Joined:
    Mar 14, 2011
    Messages:
    96
    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.
     

Share This Page