Knife Knowledge: Oxidation of Carbon Steel

[@conradh7659]

I haven’t read all the comments, but a before and after shotd would help show whats going on with oxidation and how fast. Thanks for sharing the rust/oxidation removal technique with the lemon; something I never knew.

[@nadm]

Thanks for checking this out. Definitely a useful tips. The skin does really I kind of like sandpaper.

[@coryc1904]

Thank you for the great information! I just got my first high carbon knife, I didn't even realize it was high carbon until I used it and it got kinda rusty pretty fast. Now I'm being more careful with it, but it's definitely the nicest knife I've ever used. Thank you for the tips and tricks!

[@nadm]

I have two knives that are ridiculous when it comes to oxidation. It makes me not want to use them. The other ones take their time getting a patina. It comes with the territory. Good luck! Thanks for coming!

[@muriellivermore2560]

Love how real to life your video is. Thanks for not editing out everything!

[@nadm]

Thank you. We have tried to hold true that exact idea. We never knew he would like it or he didn't but it seems to be the general consensus. That comment means a lot to us.

[@D2G10]

Video is a time wasting garbage. There is no need to force viewers to watch how the knife oxidizes for 12+ minutes

[@Patrick-nl6ug]

Works a treat, thank you!

[@nadm]

Great to hear!

[@jwsavedn88]

That was very helpful. Thank you!

[@lumbago69]

I’m kinda confused. If the lemon caused the rust wouldn’t rubbing it with more lemon cause more rust? Sorry I’m new to the knife world

[@nadm]

So there are different things that are acidic or salty. You might be cutting onions and then you could use the onion to loosen up the rust. You really should keep a damp towel ready to wipe down your knife constantly while using it if it’s a carbon steel knife. If you walk away and found that some rust is there and you tried to wipe it off you would find that it does not come off. You would then add some acid back to it to help loosen the newly formed rust and then you would use the peel as sandpaper to remove it.

[@AJ-by6pd]

I like Bar Keeper’s Friend. It seems to do the trick.

[@NH_RSA__]

What if you were to use baking soda and water mixture for your wipe off towel?

[@nadm]

That sounds like it can work. Let me know.

[@Reza-nz2re]

Nice Takeshi Saji petty. That Rust eraser look like medium grit because I see some faded white writing in there. Fine grit Rust eraser is red color write or stamp. Always great to see your channel Greg 👍. Very informative and help me make the Decision. Thank you and GBU

[@nadm]

So I have both medium and fine grit. I tend to use the medium one on the stones. I'll grab the fine one and see if it works just to try to keep the scratches to a minimum and then I go to the medium one if the final one is not working.

[@tom_nuyts]

very good demonstration and competent informations . I use the sam trick for the anti-oxidation of my "Solingen Windmühlenmesser - with very thin grinder blades of carbon steel". And more and more I try to avoid oxidation and patina effects, because actually they decarbonize the surface and make it more and more uneven, so that the cutting experience suffers from this increasing roughness. (Those guys in Solingen originally developed a special blue fine polishing of their HRC 61 blades to avoid rust development in times before stainless steels came up ... rather effective, I have to say...) @ rust eraser: instead of that "unknown" material and composition I use a belt to clean up the dry blade, very successfully and very carefully

[@nadm]

Thank you for that. I do like the knives that have a patina already put on them before you get them. It seems to add some type of protection. I don't like trying to remove the oxidation because sometimes you'll make scratch marks. It's good to do it with the peel of the lemon because it doesn't give you that proble. I appreciate that. It would be cool to see that you might give me a link.

[@lz_377]

I’ve found that grabbing some high quality sand paper from Lowe’s starting at 600 and going up to 2000 takes care of it in 10 minutes. Finishing with the 2k leaves not a mirror polish but removes any scratch marks and puts a gorgeous finish on carbon steel. I wish YT would allow pictures in comments.

[@nadm]

The problem is when you have a mirror finish and you like your mirror finish. If you were using that on Honyaki Then it would be a problem. Not everybody has the ability to polish to a mirror finish because it takes practice. Diamond lapping film can also be too rough on soft steel. All of this is acquired knowledge through practice and unfortunately, failure.

[@thiago.assumpcao]

Problem is mirror finish has better corrosion resistance than 2k. If you want to use an abrasive I would first try chromium oxide. Lemon is quite interesting because its available and will preserve the patina.

[@Reza-nz2re]

You can use Koyo blue polishing compound for removing mild rust and patina. Give shine to the knife and doesn't scratch your knife. I use it on my mirror finish knife and most of Japanese chef in Japan use koyo blue to maintain and cleaning their blade

[@AC-wl7ve]

Just use barkeepers friend

[@BariTone7-v5r]

Is the petty by Takeshi Saji?

[@nadm]

Yes it is

[@CajunSmack]

Appreciate your content. The skin of the lemon trick was the first I've ever heard. I usually bring out the core steel of my customs with white vinegar so the customer has a little patina already built up and doesn't get surprised.

[@nadm]

BOOM!

[@munmooo]

very nice Petty! Is it made from stag?

[@nadm]

Yes it is!

[@lloydlacasse7552]

In a kitchen I usually keep a damp rag to clean my knife off and a dry rag Is to dry it after

[@nadm]

Absolutely. I was just showing people how to solve the problem in case it gets away from them. That particular knife oxidizes extremely fast

[@kanekochera57]

I prefer having a thin layer of black patina on my high carbon knives. Its a barrier so that red rust has a hard time forming

[@nadm]

Yes!

[@kanekochera57]

@@nadm I use a passed down, family set of vintage Olde Forge hi carbon steel knives. If only these knives could talk

[@nadm]

@@kanekochera57 Now you need to go try to get them all back

[@CreachterZ]

Should you force a patina on a new knife?

[@nadm]

The only reason that I might say yes is if you want one that is uniform. It does come out aesthetically amazing.

[@deanlongthon4963]

Add a little baking soda to water to soak your wipe down cloth when using low pH acidic fruits and vegetables

[@theresahanken4295]

Someone told me that carbon steel will give food a metallic taste. Is that true? Thank you for your time and expertise! :)

[@nadm]

That is incorrect. It does not leave any flavor on your food. They are the preferred knives of Japanese chefs and a lot of chefs around the world. They're razor sharp which means they don't express any juice from the food onto your cutting board. You're able to cut food in the same size and shape so they cook evenly. You do not crush the cells of the food to retain its flavor. You're welcome and we really appreciate your support.

[@theresahanken4295]

@@nadm Thank you!

[@fionnhovawart9594]

​@@nadm Try to cut onions and you'll taste the iron in the onions - that's the reason why I switch to CrNi or PM steel BR from 🇦🇹

[@martinhafner2201]

Flitz metal polish would be very fine and cause less damage than the eraser. It is about 7000 grit, so it can get to a milky mirror finish. Or rub green (chromium dioxide) compound on a piece of leather and rub that into the metal for another very fine polishing abrasive. The green paste is about 50,000 grit, so it can get to a good mirror polish. For a slightly more aggressive scrub, use white compound on leather. It is still pretty fine at about 9000 grit and will get to a slightly milky mirror polish. You can get the compounds at most any hardware store that sells buffing wheel stuff. I don't think the red paste will work. It is based on iron oxide, so it might assist the rust and it will be too soft to polish the hard steel very well.

[@nadm]

The goal was to show them and so I definitely enjoy and appreciate your input. I don't know that everyone can afford or will have all of these compounds available. We were trying to keep it as simple as possible. Usually the skin of the lemon will do the job. If we have a deeper layer of rust then I enjoy your suggestions.

[@trappenweisseguy27]

If your knife comes with a kurouchi finish (black forging scale) leave it on. My 5 year old blade still retains most of its ku finish and that finish does a great job of keeping oxidation away. When I’m using it on onions etc I will give it a quick rinse every 5-10 minutes under the faucet. If I were doing something like making homemade marmalade and making hundreds of cuts in citrus I will use a stainless blade and resign myself to having to sharpen it several times in the process 🥴.

[@trappenweisseguy27]

Yup, right knife for the job. I actually have made marmalade before and literally had to use 3-4 stainless knives due to the blunting effect of the seeds. If I’m making just a couple of cuts I will pull a stainless out and use that. The exception is bread. My 240 mm kiritsuke does a phenomenal job cutting bread without tearing it up. I find that once your blade road develops a patina, it’s much less reactive.

[@nadm]

Sometimes I don’t wanna be bothered and I grabbing an expensive stainless steel knife. I’m in a hurry and I could care less. Most of the time, using my nose is a great experience. I like to take the time if I can.

[@julesverne5072]

That's why I only buy japaneese knifes in gingami steel, or vg 10 and so on.. ;)

[@JuaneDosesII-wj6dd]

I use a propane torch to colorize my finest blades. I toss machetes and axes into a bonfire to harden them. If you can’t baton the knife through an oak stump it’s trash.

[@guyharrison909]

Jif works.

[@nadm]

Nice

[@BigMacOrange]

That oil can in fact go rancid.

[@nadm]

Yes, but the problem is that it doesn't really do anything. Rancid means it might have a distasteful flavor but the coding itself being so thin is really not going to harm you, but possibly give you one bite that is distasteful.

[@BigMacOrange]

@@nadm I noticed a smell but I figured it was fine. Thank you for confirming.

[@BigMacOrange]

@@nadm do you have any folding knives in Aogami super blue?

[@nadm]

@@BigMacOrange no, sir. I have one of those folding knives, but I would have to check and see if it’s made out of that.

[@BigMacOrange]

@@nadm I have a Spyderco stretch in SB and it's hard to find anyone else with any exp with it. Only a handful of videos on KZbin. I'm surprised more don't use this steel

[@user-pm7pw1tl3t]

When you get out of breath from just talking and staring at knives...

[@nadm]

Lol, that's me with my asthma.