Rust Spots on Knives
Why It Happens, Tips & Tricks To Remove It
What is it in the First place?
The Term Rust is another name for the compound called iron oxide ie. the red/orange flaky type substance that you see growing on metal. Iron oxide takes place when iron and oxygen react to moisture. And it doesn't necessarily even have to be water, if there is moisture in the air it can still make your kitchen knives appear that they are rusting.
Acidic and salty food remnants on knives will stain it therefore rinsing the pieces of food scraps and gunk off them before you put them in the sink, especially if you don't intend to wash your knives immediately, will help avoid this.
Iron is the secret ingredient of the steel found in the blade of your kitchen knives.
So, when the iron in your knives is exposed to oxygen and moisture and under the right conditions a chemical reaction can take place that gives a recipe for rust like spots.
But its stainless Steel?
Well Stainless steel is more stain-resistant, but it’s not stain-proof. It still has at least 10.5% chromium so it is still considered steel. It's best to think of stainless steel as having an extra protective layer which allows them to be 'stain-less' and not 'stain-free'.
Tips to reduce surface oxidization rust like stains
- Acidic and salty food remnants on cutlery will stain it. Rinsing the pieces off straight away before you put them in the sink to wash later, will help avoid this.
- Washed and wet cutlery left overnight has the chance of staining. Its ideal to protect the blade to wash buy hand and then towel dry immediately before storing.
- Never store wet knives into their block to dry naturally
- It's important that stainless steel and silver-plated or copper items don't come into contact, as the chemical reaction can cause discolouration.
- Stains such as watermarks can generally be wiped off easily from knife blades, and for more persistent rust stains, use a non-abrasive metal cleaning paste or liquid - one formulated for stainless steel, not a silver cleaner - if necessary.
- For rainbow-like stains, use lemon juice.
How can I remove the marks from my Knife Blade?
Now that we know exactly what rust is and how it comes about, it's time to delve into the different methods to remove this funky substance and get your knives back to pristine condition.
#1 Baking Soda
Baking soda works great on knives with light rust stains or on items made out of thin metal.
Make sure to wipe down and clean your kitchen knife properly first so no dirt interferes in the rust removal process. Opt for a cleaning solution and wipe down with a cloth when removing dirt - avoid water as moisture was the agent that caused your blade to rust in the first place.
Mix water and baking soda so that it creates a thick paste, and then spread it over the metal making sure all rusted spots are completely covered. Let the paste sit for approximately an hour.
Then using a toothbrush, scour away at the rusted spots. For extremely rusted knives, use steel wool or a slightly abrasive sponge, but take note that too much pressure can damage your knives.
Then remove the paste with water and dry thoroughly with a cloth. To give your kitchen knife a protective boost from rust and keep it lubricated, apply some mineral oil such as camellia oil which should do the trick.
#2 Vinegar Method
White vinegar contains a substance called acetic acid which attacks rust. Avoid using other types of vinegar as they may leave stains.
Soak your knife in white vinegar for roughly five minutes. Any longer and you risk damaging your knives.
After the five minutes is up, if there is still some rust remaining then progressing to the baking soda method should remove any last specks of rust. And then we recommend lubricating your blade with camellia oil to make it more rust-proof in the future.
Otherwise, just wash off the vinegar with water and wipe and dry with a cloth.