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toitkshwa21 knife rust..

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Hello everyone. (@ Chemicalkinetics)

I bought a kitchen knife for my wife a while ago via the recommendations of the members here in this thread:
chowhound.chow.com/topics/900808

This is the knife I bought:
8-inch chef knife
http://www.chefknivestogo.com/toitksh...

My wife was just complaining about it starting to rust. I know nothing about cooking or knives so what do I do to fix this? (or rather what do I tell her to do?) I did a google search for "toitkshwa21 care" but I didn't see anything specific regarding the care of this knife in regards to how I should proceed to fix this rust issue and to prevent it from coming back. Thoughts, etc.? Thank you!

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  1. Carbon steel needs pampering. Folks used to stainless are in for a shock.

    Use, wipe often during use, wash and dry immediately after use.

    Camelia oil is commonly used on carbon blades to protect them.

    http://www.chefknivestogo.com/tsoilst...

    The rust needs to be removed using the mildest cleanser that will work. DO NOT REMOVE THE BLACK AREA!

    Be very careful cleaning a really sharp blade.

    Jim

    6 Replies
    1. re: knifesavers

      @knifesavers <Use, wipe often during use, wash and dry immediately after use.>

      She has to wipe DURING usage as well? How in the world does that work exactly...? Maybe that’s why then. She said (and I have seen her) she cleans it and dries it after every usage though.

      @knifesavers <Camelia oil is commonly used on carbon blades to protect them.>

      1. Should I have bought the oil and had her use it from the get-go?

      2. What’s the process for using this oil? (ie Does she use the knife, then wash it, then dry it, then apply the oil, then lastly store it or ...? how does this work? [that is, if I need this oil in the first place] )

      1. re: bloodboy

        ....She has to wipe DURING usage as well? How in the world does that work exactly...?

        I normally, just have a damp towel next to me and will periodically wipe the blade / cutting board. The blade steel and patina maturity, will dictate how frequently you need to do it.

        ....1. Should I have bought the oil and had her use it from the get-go?
        Some carbons are a PITA and need it, others are fine without it.

        ....2. What’s the process for using this oil? (ie Does she use the knife, then wash it, then dry it, then apply the oil, then lastly store it

        Yup.

        1. re: JavaBean

          https://m.youtube.com/watch?v=tza5pym...

        2. re: bloodboy

          I think every carbon steels is a little different. Some carbon steels are more prone to rust than others. That being said, you definitely should clean and dry after the cooking. I personally do not usually clean or wipe the my knives during use.

          Rusting is an interesting process. While water can induce rust, a fully wetted knife actually undergoes the rusting process much slower. Knives actually rust faster when they are slightly wet and exposure to the oxygen in air.

          In order words, if you have a very wet knife that you are constantly working, then you are actually fine -- because you are constantly keeping it wet. If you have a wet carbon steel knife, and you allow it to sit on the counter and slowly dry out, and then wet it, and then dry out....etc, then it will induce rust.

          1. re: Chemicalkinetics

            Absolutely, different carbon steels and patina maturity makes a huge difference. Wiping the blade down, is second nature for me...I even do it with stainless :).

            1. re: JavaBean

              <Wiping the blade down, is second nature for me...I even do it with stainless :).>

              I wipe stainless steel knives too, but I only do it at the end, or if there is a big lag time. In other words, if I think I will use the knife within 1 minute, then I don't wipe it down. If I think I may do something else for awhile, then I will wipe the knife down.

      2. Yeah carbon knives need to be treated Nice. Try to dry in between activities and certainly after washing be sure to dry completelty dry.

        My wife doesn't use my carbon because she refuses to dry after use, not really that big of a deal though. I always have a towel handy and dry my knife through my cooking session. Never needed to oil it but after rust you might need to.

        1. How crusty is it? Maybe just a little barkeeper's friend is all you need. Keep that thing dry when not in use. I give my carbon steel blades a wipe with olive oil too

          1 Reply
          1. re: BiscuitBoy

            @BiscuitBoy <How crusty is it? >

            I am going to post a pic later if I get a minute.

            @BiscuitBoy <I give my carbon steel blades a wipe with olive oil too>

            Initially, I told her to perhaps oil the knife with some random oil but she said that she thought the instructions said not to oil the knife. Guess she didn’t read the instructions well obviously...

          2. Non-stainless knives will need a little more care. You will want to remove the rust by abrading it off of the knife; leaving it on could allow it to continue to develop deeper into the steel. You could use flitz polish if it isn't too deep, but I like to recommend using a small "finger" stone to get rid of rust like this one here:

            http://www.chefknivestogo.com/sarurur...

            The phrase you are using to look up the knife "toitkshwa21" is just a code name that that site uses to codify different knives in their html addresses; you are actually looking for a Tojiro ITK 210 mm gyuto. This is actually a very good knife for the money.

            Your knife is made of White #2 steel, which is a very low alloy carbon steel. Low alloy steels don't have many other elements in the steel alloy other than carbon and iron--as a result, their stain or rust resistance is much lower than a stainless steel knife that has 14%+ chromium content. I've watched both a White #1 and a Blue #1 steel knife rust within a few minutes by leaving onion juice on the blade.

            Just wipe down or rinse off your knife periodically while using it, and always wash and dry it carefully and let it air dry before putting it away. It really doesn't take a whole lot to keep it rust free.

            Additionally, over time the parts of the knife that are not under the kurouchi finish will develop a blue/orange patina that will help protect it from rust. This is a more controlled oxidation process that forms on the surface and is actually desirable.

            1 Reply
            1. re: Cynic2701

              @Cynic2701 <You could use flitz polish if it isn't too deep, but I like to recommend using a small "finger" stone to get rid of rust like this one here>

              I am going to post a pic later if I get a minute.

            2. All the other responses are great.

              Yes, rusting is very normal for this knife -- a very pure carbon steel -- a great knife for the price. It is a carbon steel afterall. However, it does not have to rust. You can build a patina. You can intentionally build one, but I think you can just keep the knife dry after use. After a week of normal use and keeping it dry, it will normally build up a patina.

              Now, back to your original question. You can easily remove minor rust with something like Bar Keeper's Friend.

              http://thriftytexan.com/wp-content/up...

              It is very good for many things. Just put small amount of Bar Keeper's Friend on your knife. Don't even add water (maybe a drop or two). Then, get out a soft brush or old tooth brush or even folded paper towel, and rub away.

              For slightly more difficult rust spots, you can cut out a small piece of the green pad, and polish the blade:

              http://www.armyproperty.com/images/Sp...

              Like knifesavers said, be care when working around a sharp knife.

              8 Replies
              1. re: Chemicalkinetics

                Note that BKF is not a good choice for removing the patina. For that you want baking soda and a fresh green Scotchbrite pad. A good rubbing with a bit of water and lots of baking soda will get you back to the base metal. The black coating is just cosmetic and can be removed (should slice better without it).

                As CK said, you can let the new patina build naturally or you can speed the process. Force the patina by blotting on mustard with a sponge and let it sit for about 5 minutes, blot some more mustard and sit for another 5 minutes, then wash it all off. You will get a speckled blade that is quite resistant to rust and will naturally acquire a deeper blue as you cut proteins.

                Many consider the patina of carbon knives attractive. But if you don't like the look, best bet is to sell the knife and get a stainless or semi-stainless blade.

                1. re: Alpncook

                  @Alpncook -
                  I just told her about the mustard method and she could care less about looks so she is going to try it in about 20 minutes. Just put mustard all over it/cover it in mustard for five minutes then cover it in a coat of mustard five minutes after applying the first coat. Five minutes after applying the second coat, wash it all off, dry it completely and air dry it then store it. Correct?

                  1. re: bloodboy

                    Well the deed is probably already done now but the idea is to just blot it on, let it sit, then blot on some more. Actual time depends on how reactive the steel is. If you don't like the results, you can always start over.

                    For ideas on patina, look at this thread:
                    http://www.kitchenknifeforums.com/sho...

                    1. re: bloodboy

                      Yup, that's the gist of it. I've found a forced patina works better by lightly scrubbing the blade with a scotch bright, wash it with warm soapy water, heat the blade with boiling hot water. Apply the mustard, white vinegar, etc, wait for it to turn grey to black, wash it / don't scrub, reheat....repeat as many times as needed. Many light layers are better than fewer thick layers.

                  2. re: Chemicalkinetics

                    I have a love/hate thing with BKF and carbon blades. While it is killer on the rust, the acidic component then has to be neutralized otherwise it attacks the blade.

                    My first choice is Bon Ami and if it doesn't work I go BKF and then have to take measures to prevent side effects.

                    Jim

                    1. re: knifesavers

                      <I have a love/hate thing with BKF and carbon blades. While it is killer on the rust, the acidic component then has to be neutralized otherwise it attacks the blade.>

                      You are right. Thanks for pointing it out. Bar Keeper's Friend, while can effectively remove rust, can and will remove patina at the same time.

                      1. re: knifesavers

                        Yup, BKF also leaves a funky grey haze. Bon ami or baking powder takes longer,but it doesn't mess up the blade finish.

                      2. re: Chemicalkinetics

                        @Chemicalkinetics <For slightly more difficult rust spots, you can cut out a small piece of the green pad, and polish the blade:>

                        That is what my wife told me she used to try and remove the rust this evening. I panicked until I read your post. I guess her instinct was correct. But I’ll still post a pic for confirmation. And I will steer clear of the BKF since it seems complicated.

                      3. Carbon steel knives will rust, if left wet or dirty for a prolonged period of time. They should be wiped with a damp towel, periodically while in use - especially with acid foods (onions, lemons, etc.), and properly cleaned & completely dry after each use. If needed, put a light coating of Camilla oil on the blade for the first couple of weeks or until the patina matures.

                        The Tojiro ITK, supposedly has some issues with a) Kurouchi finish flaking off and b) cladding itself is very reactive, rust magnet.

                        For minor rust spots, just clean the area with a mild abrasive cleanser (bon ami) or mr. clean magic eraser…wash, wipe the blade really, really dry and lightly oil it.

                        If it’s rusting immediately or if the Kurouchi finish (the black part) is flacking off, you may need to sand the entire blade down to bare metal, and form a patina (naturally or forced) and /or oil it.

                        1. I have the same knife at home. The 240 Tojiro Shirogami and live in the Tampa Bay Area. Talk about a humid place to live but I love it

                          I just wash and dry directly after use and it stays in the open when not in use. No rust

                          When doing prolonged prep work I will dry it off with a paper towel so it's not staying wet between jobs, then wash and dry when done. On some of my carbons I might find a touch of rust on the tang at the handle insertion. A non issue

                          Never leave the knife unattended without drying to take a call or to deal with other things even for 10 min.