6

I've taken the plunge to buy two expensive kitchen knives and somehow they picked up these stains (rust?) in less than 24 hours of use. I dried them, I thought completely, before putting into the block last night.

I tried to remove with vinegar but the stains didn't come off.

Any suggestions are highly appreciated.

Many thanks.

knife1

knife2

  • Did you put them in the dishwasher? Did you dry them immediately after washing? Wash immediately after use? Anything unusual about the water in your area? – Niall Dec 4 '16 at 13:17
  • What material are the knives? Some afficionado knives are made of carbon steel (non stainless). – rumtscho Dec 4 '16 at 13:31
  • I hand washed them after using with a mild dish soap, and dried with paper towels until they weren't coming off damp anymore. I don't know much about the water in my area (Florence, Italy), but none of my cheap-o knives (that go through the dishwasher every day!) have any markings on them. If they are carbon steel (I don't know if they are/aren't), is there a way to remove the stains? – Craig Dec 4 '16 at 14:46
  • Try a rubber eraser to remove light stains or a metal polish. A light coating of food grade cooking oil may protect from future rust stains. – Optionparty Dec 4 '16 at 16:16
  • 1
    @Craig IMO, you haven't mentioned anything that should explain this kind of spot-rusting. You should consider e-mailing the manufacturer and taking it up with them. – Niall Dec 4 '16 at 16:42
7

This happens a lot when the knives are more carbon steel vs. stainless steel. I have many Japanese knives, and this happens when I don't immediately wipe off the blade after washing, or when cutting up more acidic foods, and not wiping the knife off with a damp towel.

I use a Japanese rust eraser, and most if not all rust will come off, and it will not scratch the knife's surface if you run along the grain of the metal. These eraser are pretty inexpensive at your local japanese market, or you can get them on line. They have a small amount of abrasive on it.

In your case, it will be a bit difficult, as the grain of your knife is going up and down the knife. But if you don't care too much about a bit of scratching, then you could run the eraser length wise or side to side, along your knife.

Another alternative is to use a non scratching powdered cleanser, such as Bon Ami or Bar Keepers Friend and a cut potato or dai-kon (asian radish) to polish the blade. Try a small area first and then if it works, polish the whole blade. Wash and dry immediately.

To see a demonstration of this technique I would watch some youtube videos by, Jon Broida, at Japanese Knife Imports. He is a master knife sharpener and knife shop owner in Los Angeles.

1

I would check with where you bought it or the manufacturer before doing anything harsh.

A light coating of vegetable oil will slow down any future rust. If it is stainless steel it should not hurt it.

From the looks it could be carbon steel. And the spots could be rust.

You can try WD40 with a soft cloth. Probably won't work but worth a try.

Try baking soda with a little water and a scotch bright pad.

If you search the web you will see use of harsh chemicals and even sand paper. I would hold off on anything harsh. Hopefully the shop where you bought it can tell you what kind of steel and how to care for it.

I would assume it is carbon steel until you find out otherwise.

  • 4
    I was thinking carbon steel too at first, but after a bit of searching I only found X 50 Cr Mo V15 knives from that brand, which should be highly rust resistant. So, maybe a fake? Also, I would abstain from WD40 and baking soda treatments if bringing them back to the store, as the handler will look for excuses to not take them back. – rumtscho Dec 4 '16 at 17:50
  • 1
    1.4116 steel (X50CrMoV15) is considered as one of the few actually dishwasher proof cutlery steels (doesn't mean the EDGE will be unharmed in a dishwasher so don't do it). Are you sure there hasn't been something very aggressive (lime juice, undiluted cleaning chemicals, salt grains!!) sprayed/sprinkled on it? Sure that your knife block is clean of moisture and chemicals? If the knife was counterfeit, it would much more likely be of 420J2 steel (also very rustproof) than carbon steel. – rackandboneman Dec 8 '16 at 14:11
  • @rackandboneman I am not sure if there were juice or chemicals. It is not my knife. – paparazzo Dec 8 '16 at 14:33
  • 2
    Carbon steel (that hasn't yet built up patina) should stain very visibly (darkening, not rust) if an onion slice is left on the blade face for an hour or so :) Maybe test it on some unobtrusive spot. If there is ACTUAL (brown) rust from that test, assume something really is fake: that would be the behaviour of unhardened carbon steel, which has its place on blade faces but not ever on a french-style blade. – rackandboneman Dec 8 '16 at 16:52
  • @rackandboneman This is an answer (not question). It is not my knife. I don't have the knife to test. – paparazzo Dec 8 '16 at 17:01
0

Having checked the manufacturers site it seems that your knife which looks like stainless steel, is infact stainless steel. In which case it begs the question, why go spotty after such a short time? There is a possibility that this is a counterfeit product, in which case I would contact the company direct and get into dialog with them - try this link - http://www.world-of-knives.ch/en/products. It does however seem to me that your knife is made of poor quality stainless, again contact the company, it could be that they are unaware of this issue. As an aside, and a reflection on your 'cheap' knives, as I live on a boat the marine setting is very hard on my utensils, salty air is unavoidable, and a lot of my cheap knives put up with this, my victorinox knives get rust spots regularly.

You could try wiping a very thin layer of cooking oil over the knife with a piece of kitchen towel (NOT WD40), but you will find that this is not a long term situation, and will encourage critters eventually.

Your Answer

By clicking "Post Your Answer", you acknowledge that you have read our updated terms of service, privacy policy and cookie policy, and that your continued use of the website is subject to these policies.

Not the answer you're looking for? Browse other questions tagged or ask your own question.