How to Remove Rust From Stainless Steel Knives

Make sure your knife is clean.
Mix water and baking soda to create a paste.
Spread the paste over the surface rust. Let it sit for about an hour.
Rub with a toothbrush.
Rinse and dry completely.

Kitchen knife on butcher block

What you’ll learn

Why Does Stainless Steel Rust?
How To Remove Rust From Stainless Steel (The Best Method)
Alternative Method For Removing Rust
Other Methods For Removing Rust
Best Care Tips For Maintaining Your Stainless Steel Knives
Frequently Asked Questions

Wait a minute, isn’t stainless steel supposed to be stainless? Well, that was a frustrating discovery. The truth is any steel item, especially any kitchen item, which is not being taken care of properly, is prone to develop rust. Yes, including your beautiful stainless steel knives.

So, having established that stainless steel rusting is normal, of course we still want to avoid and remove rust. In this article you will learn why rust happens, how to stop it, and most importantly: how to fix it!

1. Why Does Stainless Steel Rust?

Stainless steel is an alloy consisting of iron, carbon, a minimum of 10.5% chromium and other alloying elements, mainly nickel. It is the chromium that acts as a protective layer, generating chromium oxide and sealing the surface.

Under normal conditions, if that protective layer of chromium oxide is damaged or compromised, a new layer will be formed, offering corrosion resistance. But what happens when the conditions don’t allow for chromium to regenerate? Rust. That happens.

In the kitchen environment, this usually happens when there is damage to the chromium layer or prolonged exposure to moisture; or a combination of both. Also, some dish detergents and food acids can affect the “stainless” in stainless steel.

Other factors include heat or extreme temperatures, contact with other metals or chloride-rich environments (salt).

2. How To Remove Rust From Stainless Steel (The Best Method)

a rusted knife and a knife that had rust removed

Two words: baking soda. This miraculous substance keeps surprising me, it seems the number of uses and applications are nearly infinite. So if you don’t already have some baking soda at home; go and get it. It will become handy for this and many other future missions in the household.

The advantage of using baking soda in this case is that it’s non-abrasive and it will not damage the original grain of the material. It’s gentle to your knife and utensils.

On the other hand… it will work better on thin metal and lighter stains.

What you’ll need:

¼ cup baking soda
Warm water
A toothbrush
A cloth

Clean your knife properly. If there’s any dirt on the surface, the results might not be as successful. We recommend cleaning it with a soft cloth and an adequate cleaning solution.
Mix water and baking soda. Pour the water slowly and carefully, the idea is to create a thick paste.
Spread the paste over the blade or the steel surface. Cover the rust spots or rust stain completely and let sit for about an hour.
Rub with a toothbrush. Especially the rusted area. More difficult rust spots may require the use of a stainless-steel wire brush.
Rinse away the paste using only water. Make sure to dry completely with a soft cloth.

3. Alternative Method For Removing Rust

Dalstrong Rust Eraser

If what you’re looking for is a quick touch-up or a maintenance routine to your stainless steel knife, scissors, spatulas; or you need to remove stains from your whetstone (that’s right, maintenance tools also need maintenance!); Dalstrong Dust Eraser is simply the cleaner, easier, most modern solution.

A rust eraser is a tool made from a special compound, designed to remove rust from knives and other surfaces. They are usually small and look like school rubber. They are also extremely easy to use.

Users have reported that rust erasers work wonders with high-carbon knives such as the best-seller Chef's Knife 10" from the Gladiator Series; but also AUS-10 steel, damascus steel and all kinds of stainless steel tools.

PROS:

Ideal to rub away corrosion or scuff
Designed with the best quality materials
Your favorite kitchen items will look new, shiny and clean
It can also be used to remove stains from your whetstone
You can rest easy, engravings or logos will not be damaged by this rust eraser.
Very affordable
Easy to store
It can be used on any stainless steel object like scissors, spatulas, cast-iron pans…

CONS:

If you need to remove watermarks, you may need to purchase specific products for that purpose.
You need to be careful when using it on painted surfaces, as it could remove paint.
This is a small item, perfectly-sized for knives and other kitchen tools. Some people may find it uncomfortable to use on larger surfaces.

How to use Dalstrong rust eraser:

Soak the eraser in water for approx. 5 minutes.
Rub the eraser over the stain. A few things to take into account here: 1) The knife should be placed on a flat surface 2) You should grab it firmly 3) Always, always, always rub in the direction of the grain on your steel blade and towards the edge, especially if it has a satin finish.
Apply water as needed.
Rinse with warm water.
Dry the knife completely.

Tip: Use the eraser gently, and only in the areas that need it.

4. Other Methods For Removing Rust

White Vinegar

White vinegar is just as much a superhero as baking soda. It has acetic acid, a substance that works well on rust. Don’t use other types of vinegar as they could leave stains.

Submerge your stainless steel piece in white vinegar for a few minutes. Beware, if you leave the knives in for too long, you could damage the knife blade. Rub if necessary, otherwise wash the vinegar off with clean water and dry. If there’s any rust left; we recommend using a second method like baking soda.

Lemon Juice

Lemon is acid enough to work as a stainless steel cleaner; especially if combined with a complementary substance like baking soda or salt.

Some people cover the rust stain with salt and then squeeze a lemon on top and let it sit for two hours. The rest of the process is the same as the methods described above. You can also use the baking soda method, but instead of using water to form the paste, use lemon juice to boost the effect.

Cream Tartar

“Tartaric acid” can be a rust remover too. Mix with lemon juice, apply with a sponge and scrub. Then, as you should always do: rinse with water and dry.

Oxalic acid

Oxalic acid is safe as a rust-remover for stainless steel. It’s better for larger items or stains, like a rusty stainless steel pan. You can apply it directly; buy a safe cleaning product that contains oxalic acid, or use the following technique even though it may sound like a grandmother’s tale: potato and dish soap.

You read it right. Apparently, potatoes contain oxalic acid and can be used to clean rust. Cut the potato in half, cover the open face of the potato with dish soap and salt and rub it against the stainless steel surface.

Citric Acid

Spray a citric acid solution directly into the steel and let it work for several minutes. Then wipe, rinse and dry. If there’s rust left, add some elbow grease. Citric acid could also remove or damage other coatings, so it’s not ideal for cleaning all kinds of stainless steel pieces.

Phosphoric acid

This strong substance works best for rust caused by carbon steel contamination. Please use gloves! Use a sponge to apply phosphoric acid and then brush. You will need to use ammonia to neutralize and remove the acid; and then use water to rinse the ammonia.

5. Best Care Tips For Maintaining Your Stainless Steel Knives

whetstones on cutting block with kitchen knife

#400 / #1000 Grit Premium Whetstone Set

Sure, here we’re giving you the solutions for rust removal. But why not prevent rust from happening in the first place?

Even though stainless steel knives are one of the most resistant and long-lasting knives, here are some recommendations to keep them at their best performance:

Moisture is your greatest enemy when it comes to rust. Keep knives clean and dry, and store them away from damp environments. Do not leave them in the sink.
Reduce dishwasher time to a minimum (or avoid completely if possible), even though they are dishwasher safe. The chemicals and the temperature are not kind conditions for your knife.
The best way to clean stainless steel utensils daily is with a mild solution of warm water and mild soap or dish soap.
Always use a cloth to rub the surface, another one to remove soap, and finally use a microfiber cloth or paper towel to dry the surface thoroughly.
If you are going to use cleaning products, make sure you know which ones work well as stainless steel cleaners. Avoid cleaners in the chloride family, which are very abrasive and damage the protective chrome oxide layer on the blade.
Do not use steel wool or other abrasive cleaning tools, which can scratch the surface of knives and damage their finish, exposing them to corrosion.
Avoid placing your knives together with cast iron products.
Some stainless steel polishing products can cause discoloration if they are subject to intense heat. In any case, keep your knives away from high temperatures.
Detergents and mineral salts in tap water can also damage your knife.
Wash and dry your knives separately from other cutlery, immediately after use, to avoid possible pitting and staining from foods such as salt, vinegar or acidic foods.
Stainless steel knives don’t need as much oiling as carbon steel, for example. Still, it wouldn’t hurt to apply neutral oil to your knives two or three times a year.
After you clean rust and stains from your knife, remember to get it sharpened with a whetstone and straighten the edge with a honing rod. It will look and feel like new... or even better.

6. Frequently Asked Questions

Dalstrong Knife Rust Eraser

What’s the difference between metal and steel?

Metal is a natural element (that means, an element that exists naturally on Earth); while steel is a product of human intervention. Steel contains metal like iron, combined with other elements. Steel is stronger than metal and practically indestructible.

What’s the difference between rust and corrosion?

Corrosion is a deterioration process, which can sometimes take the form of rust. Therefore, rust is a type of corrosion that only occurs on iron and its alloys.

Does WD-40 remove rust from stainless?

WD-40 can help remove rust from stainless steel, normally without damaging the surface. However, it should be used with caution in items that are in contact with food.

Does Aluminum Rust?

Aluminum is not subject to rust, but it is to corrosion.

What should I avoid when cleaning stainless steel?

You should avoid steel wool or textures that would scratch the surface; as well as abrasive cleaning solutions and bleach / chlorine.

How can I remove black stains from stainless steel?

Stainless steel turning black is a sign of oxidation. Usually, the vinegar - or baking soda solutions mentioned above should take care of the problem.

How can you remove stains from stainless steel knives?

Most of the homemade cleaning methods described above, such as baking soda, lemon juice and vinegar, will usually work with any stain on your blade.

How do you remove rust from a stainless steel appliance?

White vinegar is a home-favorite when it comes to cleaning and removing dust from appliances. For stubborn rust; a rust cleaner containing oxalic acid could be more effective.

How long do stainless steel knives stay sharp?

You can hone your knives every 2-4 uses, some do it after every use. Actually sharpening your knives (with a whetstone) can be done once or twice per year.