Please help after laughing at me 🥹 (after putting knife in Lemon+Cola)

[fishface5]

You can use Flitz to polish it, but it probably won't look exactly as new, and since the blade is carbon steel if it cuts or comes into contact with anything that is at all acidic then it will discolor again.

 

[BigW]

WD-40 won't provide long-lasting rust protection, it evaporates far too quick and it is more for cleaning and to get rid of water / moisture, .....I use Lanolin instead, e.g. for my Terava Skrama. Here down under you get it from the hardware stores, if you can't find it in your stores, Amazone will have it...

 

[Dextar]

Update:

Thanks for all of your advices, special thanks to Mk-211, FortyTwoBlades, Bill DeShivs.
Now the rusts are removed, only problems:
1. there are many "scratches" after wiping down, at the time the new knife arrived, I concerned about 2 scratches, now I don't have any concern, but is there a way to polish it?
2. after applying WD-40, the it feels "greasy" every time I touch and handle it, is it safe if I touch food after handling the knife? Is there a way to remove the oil-feeling?

Here are the "new" knife, thank you all once again.

 

[Dextar]

If not being used for food, just hose it down with WD-40.

Thank you once again for this remind, I didn't realize it and this really saves me.

 

[Mk-211]

I would spray some cleaner, like windex on a rag or paper towel. Then wipe down the handles, if there's WD-40 on them.

I use a vegetable wash to clean any knife that will cut food. That way it doesn't contaminate the food and or possibly make you sick.

 

[edgelion]

Scratches never bothered me, but yes, with a lot of careful polishing they can be reduced.

For the residual wd-40 - it should easily wipe away with even a dry cloth. What remains internally will continue to displace water as it evaporates. A single drop of pivot oil will last longer now that the rust is gone.

It looks like you've done a fine cleaning job. Keep up simple maintenance: clean the blade every time, protect it with a small amount of food safe oil, and use rust remover when needed. When it becomes second nature, you won't even have to think about it. Wipe the blade when carrying - I do this almost constantly before I fold it/sheath any knife in the field. I'm personally more lax about oiling my blades before storage, though. But, like you, it's how I learned to contend with rust.

 

[fishface5]

To get rid of the scratches you would need to sand off all of the metal of the blade down to the level of the scratches, which would take a lot of work, including using progressively finer grits depending on how clean and shiny you wanted it to look.

Another less intensive option would be to try to cover up the scratches by sanding a new consistent scratch pattern onto the blade.

Either way you want to use sandpaper that is glued to a hard flat backing material, probably sanding legthwise i.e. parallel to the spine.
But either way you risk sanding off the etching.

 

[FortyTwoBlades]

WD-40 is not food contact safe, so you don't want it getting on food, though it's not likely to kill you if you accidentally ingest trace amounts. Still just not something you'd want to do. If you need food-safe oil for it you can use food-grade mineral oil or silicone oil (the grade matters!) which are both relatively heavy oils, or for a thinner oil there's my Desert Whale liquid wax. For blade protection I generally prefer waxes over oils, which I use for lubrication instead. Oil on blades tends to bead up or leave bare patches over time, while waxes remain in place. Both will wear off a blade in use, so require periodic reapplication for continued protection.

 

[BigW]

you can use Ballistol instead of WD-40 if you don't mind the costs.....Ballistol is a premium product and actually food safe....

Eta: you will get it on Amazon