How To Get Rust Off Knives

Knives lose some of their longevity and performance when they begin to rust. First, rust erodes the blade's edge and cutting power, making cutting difficult and challenging. Rust also erodes the knife's metal, weakening its structural integrity and increasing the likelihood of chipping and breaking. Furthermore, when food is being prepared, rust can introduce unfavorable tastes and pollutants, lowering its quality and perhaps posing health hazards.

For anyone involved in cooking, be it a professional chef, home cook, or carpenter, rusting knives can be a hassle. In this post, the Benchmark Abrasives team discusses the main reasons why knives rust and offers helpful rust removal advice to keep your blades looking great for years to come.

COMMON REASONS FOR RUSTING KNIFE

Rusting knives can be caused by a number of things, including bad maintenance techniques and environmental factors. Below is an outline of the most common causes.

• EXPOSURE TO HUMIDITY AND MOISTURE

Wet or humid settings are a prime place for knives to rust. Moisture speeds up the oxidation process, which causes the blade to rust. Knives that are not completely dried after use or that are kept in moist places—like a kitchen sink or dishwasher—may experience this.

• INADEQUATE HANDLING AND STORAGE
  

Additionally, improper handling and storage practices contribute to knife rusting. Rust formation is more likely to occur when knives are stored in a manner that permits contact with moisture, like in an unprotected drawer.

• FOOD RESIDUES AND ACIDIC SUBSTANCES
  

Acidic ingredients, such as vinegar, citrus fruits, and tomatoes, can react with knife metal to cause rusting. These meals are commonplace. Rust formation can be accelerated in knives if food residue is left on the blade for prolonged periods or if the knives are not cleaned right away after coming into contact with acidic materials.

• KNIVES OF LOW QUALITY OR IMPROPER MAINTENANCE 

Rusting is more common in blades of lower quality or those that have not been adequately maintained. Low-quality blades could be more prone to rusting even after very brief exposure to moisture due to their poor corrosion resistance. In a similar vein, blades that haven't been thoroughly cleaned, dried, and oiled may eventually rust.

IMPACT OF RUST ON KNIVES

Beyond cosmetic issues, rust on knives can reduce their value and usability, cause health issues, and give the blade a filthy, unsanitary appearance. As an example:

• Rust can seriously impair a knife's functionality. Its corroding metal surface may impact the blade's sharpness and cutting power, possibly leading to uneven edges and pitting. This results in a less accurate and effective cutting experience, increasing the difficulty and duration of activities.
• Rust on blades poses a risk to one's health and safety. Particles of rust may seep into the meal being cooked, thus adding impurities or disagreeable tastes. Food tainted with rust might be harmful to your health. Furthermore, rust-weakened blades are more likely to crack or shatter while in use, raising the possibility of mishaps and injury.
• Rusted blades have an ugly appearance due to their rough texture and reddish-brown discoloration. In addition to being valuable tools, knives are also highly valued items for many collectors. Not only does rust diminish their aesthetic appeal, but it also reduces their market worth in the event that you decide to sell them.

PROCESS OF RUST REMOVAL FOR KNIVES

When you find rust on your blades, determine how bad it is. Ascertain whether the rust is limited to the metal's surface or if it has extended beyond. This assessment will assist you in selecting the proper rust removal technique.

After that, wash the knife in warm water and mild soap to remove dirt or debris. Use a soft brush or cloth to gently remove loose rust from the blade. Take care not to clean the blade too hard, as this could cause more damage.

RUST REMOVAL METHODS

There are numerous efficient ways to get rid of rust. The amount of rust on the blade will determine which choice is preferable.

A. SALT AND LEMON METHOD

SUPPLIES: water, soft cloth, steel wool, or a wire brush with a mild abrasiveness, salt, fresh lemon, and lemon rind.

STEPS:

• Make sure a liberal amount of salt completely covers the rusty sections of the knife. 
• Let the salt thoroughly soak the impacted regions by squeezing fresh lemon juice over it. 
• Let the lemon juice and salt combination remain for about two hours on the areas that have rusted. 
• After the soaking period, use a lemon rind to scrub the rusty areas in a circular or back-and-forth motion. The abrasiveness of the salt and the acidity of the lemon break down the rust.
• If more rust is present, you can gently scrub the affected areas with steel wool or a wire brush with a little abrasion. Avoid applying excessive pressure, as this could scratch the blade. 
• Give the knife a quick rinse under water to remove any last bits of rust, lemon juice, or salt. 
• Use a gentle cloth to dry the knife altogether, eliminating any remaining moisture from producing more rust.

Pro Tip: For little rust spots on a knife, the lemon and salt approach works really well. However, be careful not to harm the blade's surface with steel wool or an abrasive brush.

B. POTATO METHOD

SUPPLIES: Soft cloth, oil, and raw potatoes.

STEPS:

• Cut an uncooked potato in half. 
• To ensure that the potato and rust make solid contact, forcefully press the rusty portions of the knife into the potato's sliced side. 
• Give the knife and potato some hours to sit on the rusty areas. The oxalic acid that potatoes naturally contain helps prevent rust. 
• Take the knife out of the potato after the specified amount of time. 
• To get rid of any remaining rust particles and stop additional corrosion, oil-clean the blade. 
• Make sure there is no moisture left on the knife by completely drying it with a soft cloth.

The potato method for rust removal from knives is unexpected but very successful. The potato's oxalic acid dissolves the rust and facilitates its removal.

C. ONION METHOD

SUPPLIES: Soft cloth and onion.

STEPS:

• Slice an onion in half, fresh from the vine. 
• With the onion half firmly grasped, move the corroded sections of the knife back and forth over the onion's sliced side. Use light pressure when advancing the knife. 
• For several minutes, keep slicing the blade over the onion. Onions' sulfenic acid aids in the breakdown of rust. You might see that the onion's rust is beginning to flake off as you slide the knife over it.
• After you have thoroughly cut the onion with the knife, use a soft towel to remove any leftover rust particles. 
• To remove any traces of the onion, give the knife a thorough wash with water and mild dish soap. 
• Using a gentle cloth, completely dry the knife to stop any remaining moisture from rusting it further. 

Rust on a knife can be quickly and naturally removed with the onion method. Onions' sulfenic acid aids in rust breakdown, making it easier to remove.

D. VINEGAR SOAK METHOD

SUPPLIES: White vinegar, water, mild dish soap, a soft cloth or brush, and a container big enough to soak the knife.

STEPS:

• In a jar, mix one part white vinegar to one part water. 
• Make sure the blade is completely submerged as you immerse the rusty portions of the knife in the vinegar solution. 
• Depending on how bad the rust is, immerse the knife for a few hours or overnight. 
• After soaking, carefully clean away the loosened rust using a soft cloth or brush. 
• To get rid of any vinegar residue, rinse the knife with water and a small amount of dish soap. 
• Dry the knife completely to stop more rust from forming.

PRO TIP: White vinegar contains acetic acid, which combats rust. Avoid using other types of vinegar, as they could leave stains.

E. BAKING SODA PASTE METHOD

SUPPLIES: baking soda, water, and a soft cloth or brush.

STEPS:

• To make a thick paste, combine baking soda with a tiny amount of water. 
• As you apply the paste to the rusty areas, make sure the knife's afflicted surfaces are covered. 
• Give the paste a few minutes to rest on the corroded areas. 
• Lightly clean the rusty areas with a soft cloth or brush while using mild pressure.
• To get rid of the paste and loosen rust particles, rinse the knife under water. 
• Make sure the knife is completely dry to avoid any moisture left behind that could lead to more rust.
  

Pro Tip: Knives with thinner metal blades or mild rust spots are best suited for using baking soda.

F. COMMERCIAL RUST REMOVAL PRODUCTS

SUPPLIES: Water, mild dish soap, soft cloth or brush, and a commercial rust removal product (such as rust erasers or remover gel) are required supplies.

STEPS:

• Observe the directions for the commercial rust removal product that you have selected. 
• Make sure the entire afflicted region of the knife is covered when using the rust removal product. 
• As directed in the directions, let the product sit for the suggested amount of time. 
• To get rid of the rust, gently scrub the corroded spots with a soft cloth or brush. 
• To remove any remaining rust removal product residue, rinse the knife with water and mild dish soap. 
• Make sure the knife is completely dry to avoid any moisture left behind that could lead to more rust.
  

PRO TIP: Use caution when applying professional rust removers to kitchen knives. Many of them can be dangerous if swallowed by accident.

G. SANDPAPER METHOD

SUPPLIES: water, soft cloth or brush, mild dish soap or WD-40, waterproof sanding sheets in different grits.

STEPS:

• To begin removing rust, choose a sanding sheet with medium grit, like 120 or 180 grit. The wet sanding process makes the sheet's waterproof nature crucial. 
• To make a lubricating solution, wet the sanding sheet with a mixture of water and a tiny quantity of dish soap. You can apply WD-40 as well. 
• Using the damp sheet, lightly massage the rusty regions in a circular or back-and-forth motion while holding the knife firmly. Monitor the situation and alter the pressure as necessary. Avoid using too much force to avoid injuring the blade.
• To polish the surface further after the rust has been removed, use sandpaper with a finer grain (320 or 400 grit, for example). 
• To get rid of any leftover sanding residue, rinse the knife under water.
  Make sure the knife is completely dry to avoid any moisture left behind that could lead to more rust.
  

PRO TIP: When using sandpaper or any other abrasive product, always remember to take the necessary safety precautions, such as donning protective gloves and eye protection. Once the rust has been successfully removed, keep up with routine maintenance procedures and store your knife properly to avoid rust formation in the future.

POLISHING AND RESTORING THE KNIFE BLADE

Once the rust has been effectively eliminated, the knife blade needs to be restored and polished. To restore a sharp cutting edge, use a honing rod or sharpening stone. To get a polished finish, repeat with finer grits if needed. This action will improve both the functionality and appearance of the blade.

AFTER-TREATMENT MANAGEMENT AND CARE

After the rust has been removed and restored, take precautions to prevent rust from forming again. This entails completely drying the knife after every use and regularly lubricating the blade with an oil or lubricant that is safe for food. Proper storage in a dry atmosphere is also essential for long-term rust prevention.

CONCLUSION

Save your beloved knives from becoming less practical and more beautiful due to rust. To keep your blades in the best possible shape, take preventative precautions, take quick action should you see any rust, and arm yourself with the necessary information and tools. With the right upkeep and care, your knives will continue to function well in the kitchen and other areas.