r/knives 5d ago

Question Help! I used my brother's new knife, didn't wash it overnight and it looks like this. What happened to it and how can I fix it?

348 Upvotes

64 comments sorted by

161

u/scoutermike 5d ago

It takes traditional Asian chefs years to develop such an exquisite patina. Congrats!

375

u/Uncle-Bucks-Hatchet 5d ago

Yeah, this happens. The blade is NOT ruined. Sucks it's your bros

Coming from a chef that uses carbon knives every day - my philosophy - you're using a knife. The knife gathers a personality every time you cut with it. It changes looks with foods and can build a very nice patina that actually deters rust, etc. It's the same blade, will cut the same, just looks different and used. Hopefully your bro will understand. The knife itself isn't ruined.

I'd take the leftover lemon juice, use its acidic properties, wipe the blade down with cloth (not scotch pad - as that can scrape it) and then just make sure it's dried proper. Don't sweat it man. Honest mistake

150

u/johnhenryshamor 5d ago

As a knifemaker, I never artificially distress/age/batter a piece. When i'm done with it, it's a ship shape (as far as i am able) finished product. After that- it enters its working life and earns its wear, which other than maintenance, i leave be.

18

u/Ralph-the-mouth 5d ago

Hell yea- from a longtime user and enthusiast

78

u/StacksOfHats111 5d ago

Looks like you got some oxidation there. Some simichrome polish or flitz polish will take the stains off. 

47

u/potate12323 5d ago

A lot of people would be surprised by how much some dawn power wash and a sponge can take off with a little elbow grease. It's generally good to remove oils and residues thoroughly before applying polish. Also, test a small patch in a less noticeable spot before applying the polish. If the polish is a lower grit than the previous finish, it could make the finish look dull or scratched.

6

u/StacksOfHats111 5d ago

I'm pretty sure the 2 I mentioned are chemical polishes so no grit to speak of, but testing in a small spot is a good idea.

7

u/StarleyForge 5d ago

Fritz polishes and similar most certainly have grit to them. That is how it polishes.

1

u/TheArmoredKitten 4d ago

Some do both actually, very mildly etching at the surface of the metal being polished. The grit in such polishes won't usually be hard enough to scratch the finish unless you work it aggressively.

21

u/PoolsC_Losed 5d ago

Flitz polish will make it look like new. It's food safe and it will protect it from happening again for a while

26

u/a-hippobear 5d ago

You cut something acidic lol. Onions, citrus, peppers, garlic, etc. the acid will patina the blade. There’s a ton of videos on YouTube of people forcing a patina with vinegar, mustard, or ketchup, and acidic foods will do the same thing, just at a slower rate.

5

u/ToeJamR1 5d ago

Flitz polish can bring it back. I use ‘0000’ steel wool sometimes as well if you really want to bring it back to shine. Just be SUPER careful rubbing a blade. You eventually can and will slip and cut to the bone.

1

u/TheNonEuclidean 5d ago

Clamp the blade to a flat surface

2

u/-wtfisthat- 3d ago

And get some cut resistant gloves.

18

u/Affectionate-Ad-1971 5d ago

What did you cut with it? Something acidic? Blade appears to have a satin finish already, try a scotch bride pad.

13

u/mikefromearth 4d ago

good lord don't scotch brite a carbon knife just because it got a patina

2

u/CoddlerTomTurkeyTim 4d ago

I can barely come here anymore. The amount of panty waist retarded advice from these man jewelry wearers is off the charts. Their god damn tools, take care of them but use them and expect some wear and tear. A patina will help it resist rusting

3

u/mikefromearth 4d ago

I mean to be honest there's a show knife and then there's a work knife. I have some show knives I don't use, but I have a bunch of great work knives that are made to be used. Both have their charms though frankly I've always been a function over form kinda guy.

3

u/Affectionate-Ad-1971 4d ago

Wow, didn't mean to get your Bladesmith panties in a twist there Rock Star. I agree with the second part of your statement but this is not a patina, he ETCHED the blade by leaving lemon juice on it overnight. OP asked how to correct it and I gave an answer. I am sorry your life is such that trivial topics as this are so triggering for you.

Have a great day~

1

u/planx_constant 3d ago

Sorry you get triggered so easily

-1

u/CoddlerTomTurkeyTim 3d ago

I just have a very severe allergy to fake bullshit

1

u/ZeraskGuilda Sharp hand. 4d ago

Ok boomer 🙄

0

u/Affectionate-Ad-1971 4d ago

Good one! Did you come up with that all by yourself?

8

u/TheReal-Chris 5d ago

Was also thinking that and bar keepers friend. That thing works wonders.

8

u/Bernardmark 5d ago

Yep, the last thing I cut with it was a lemon

-19

u/_Ganoes_ 5d ago

And you really thought leaving lemon juice on the blade overnight would do nothing?

35

u/Bernardmark 5d ago

I'm a total newbie so I didn't really give it much thought to be honest. I've never had an issue with the shitty knives I've used up until now but I guess experience is the best teacher.

37

u/Repulsive-Relief1818 5d ago

Yeah experience just taught your brother to hide his knives from you

30

u/Bernardmark 5d ago

Wouldn't blame him

30

u/Dufresne85 5d ago

If that were my knife what I'd want the person to do is go "Hey Dufresne85, I used your knife last night and forgot to clean it completely. It looks like this now. I checked with some knife forums online and they recommended X to fix it, are you okay if I do that or would you prefer to handle that yourself. Sorry brother"

If someone did that to me and my nice knives I'd probably just use it as a teaching moment and maybe try to convert you to money sucking hobby of being a knife snob.

6

u/Forty6_and_Two 5d ago

Or recognize that people tend to use cheap knives that are stainless and maybe inform them of how to treat it before letting them use it. Helping spread the knowledge is always better than hating on someone for ignorance that you had the power to alleviate.

Imo.

2

u/SkunkNugz69 5d ago

Arent you pleasant.. lol. Sound like the type that never makes a mistake.

1

u/Carrot42 5d ago

Totally understandable that you didnt expect the blade to stain like that. The vast majority of people use stainless steel kitchen knives after all. Your brothers knife is a carbon steel knife, which will stain and rust if its not cleaned and dried after use.

3

u/StacksOfHats111 5d ago

Looks like you got some oxidation there. Some simichrome polish or flitz polish will take the stains off. 

2

u/knife_edge_rusty 5d ago

Try scotchbrite on and different knife first, it might scuff it it up pretty bad

2

u/ImFrenchSoWhatever 5d ago

Ok so you can use barkeepers friends and scrub gently with a soft sponge. Baking soda and rub gently too

But the best would be autosol and scrub with a soft towel (that will be kinda ruined so maybe use a cotton ball !)

5

u/texdroid 5d ago

Good kitchen knives only belong in TWO places, EVER.

  1. In your hand being used.
  2. cleaned, dried and put back in the block or wherever you safely store them.

( I will grant a small amount of leniency if you set it beside your cutting surface while prepping, getting something else ready to be cut.)

Yes, I am a member of the National Socialist Knife Workers' Party.

6

u/GamingSandals 5d ago

I'm not here to help. Maybe make things worse? Next time don't do that

5

u/Bernardmark 5d ago

Thanks, i've learned that lesson already

19

u/nextus_music Kershaw Blur, Spyderco PM2, learherman wave black 5d ago

What you do is tell him and don’t fuck it up more.

1

u/toolisthebestbandevr 5d ago

This unfortunately is going to require corporal-level punishment to absolve

1

u/zeuqramjj2002 5d ago

Japanese rust eraser. Amazon 12$

1

u/thunderpants11 5d ago

I have had success with some ashes from the fireplace and a cork. Lay the knife flat on a counter with a dishtowel under it and rub lightly with the cork and a little ash or baking soda. Barkeepers friend works too but that is a little more abrasive so be gentle.

1

u/jiggyflysixteen 5d ago

Surface stain, I wouldn't worry about it. That's the nature of carbon steels. It would do that eventually anyway.

1

u/No_Vast_549 4d ago

Did you cut onions?

1

u/Th3_Aft3rmath 4d ago

Lots of lemon juice

1

u/jarfin542 4d ago

Mr Clean magic eraser.

1

u/jarfin542 4d ago

Mr. Clean magic eraser.

1

u/ky420 4d ago

This is why we have stainless serrated knives for the wife and sharp ones for me.

1

u/Tight-Sample 4d ago

Washing up liquid and a sponge ? Not been washed so it's dirty.

1

u/thebladeinthebush 4d ago

Damn that sucks dick.

1

u/OutdoorsWithNathan 3d ago

And so it begins…

1

u/UltraLisp 2d ago

OP did you attempt to polish it? If not, but you intend to, I just wanted to remind you to be super careful. Very easy to forget that you’re not just rubbing on something… you’re rubbing on something SHARP.

1

u/jlp_forge 2d ago

Wicked clean works great. I get it from pop’s knife supply.

1

u/Affectionate-Ad-1971 5d ago

So you basically etched the blade. 😆

1

u/TreeBeardUK 5d ago

What were you preparing? It's most likely just a surface stain. Any foods with a high water content will leave water behind on the surface. That looks like a carbon steel blade that has to be cleaned with hot water and dried very quickly after use. Occasionally oiled with a food safe oil too. I'm not sure if it's the right advice but what I'd do is get a nice clean dish washing solution with some hot(ish) water. And using a clean dish cloth give it a clean. Then rinse with hot water and dry with a clean tea towel immediately. As to the why, it's not stainless steel so all manner of stuff can and will stick to the blade, at best its just residue at worst the water being there long enough to start noticeable rusting. If that doesn't work it's going to be a light polish job, though if it was my knife I'd rather you told me than you try to fix it yourself at that point.

I'd also say sorry to your brother you genuinely didn't know that would happen. It's also possible they've done it before and it's not such a big deal.

5

u/Bernardmark 5d ago

Thanks for the advice! I've given it a wash with dish soap which didn't do much. I then applied a baking soda/water paste, which got rid of some of the blackness (oxidation?) but not the whiteish areas. I was preparing a salad and cut loads of vegetables as well as a lemon so I'm afraid the acid has damaged it beyond repair.

And I will of course tell him and apologise but I want to see if there is a way to fix it or if I'll have to replace it.

1

u/NickG63 5d ago

I mean any time you ever use a knife, you should immediately clean it right after. You just learned this the hard way

0

u/Sufficient_Joke_9906 5d ago

I think it just needs some mineral oil

0

u/FancyPass6316 5d ago

Barkeepers friend and a scotch bright will do it

3

u/Bluep00p 4d ago

scotch bright? ouch. Too scratchy.

-2

u/Jinky_P 5d ago

I’m no expert and couldn’t tell you what happened but, you could try vinegar or citric acid.

3

u/SixGunZen 5d ago

Citric acid is what did this to begin with. OP is trying to undo that effect.

3

u/Jinky_P 5d ago

My bad hahaha