Common Knife Ailments and How to Fix Them

Rusty Knife: How to Remove Rust and Keep It Off

Rust is the most common complaint, especially on carbon and tool steels such as D2, which hold a fine edge and pay for it with less resistance to moisture. It starts where water sits: along the edge, in the pivot, under a pocket clip. A little surface rust is cosmetic. Left alone it pits the steel and roughens the edge.

How to fix a rusty knife:

1. Clean the blade. Wash it in warm water with a little dish soap and a soft cloth to get the dirt off, so you are working on rust and not grime.
2. Remove the rust. For light rust, make a paste of baking soda and water, spread it on the spots, and rub gently with a soft brush or very fine steel wool. For heavier rust, a penetrating oil such as WD-40 or a metal polish, rubbed in small circles, lifts it. Work along the blade, not across the edge.
3. Rinse and dry. Rinse, then dry completely, including the pivot and the inside of the clip. Any water left behind starts the next rust spot.

Preventing rust:

• Store it dry. A cool, dry drawer or a breathable sleeve, never a sealed bag and never long-term in a leather sheath. How to store your knives covers it.
• Oil it. A thin film of mineral oil or a light knife oil on the blade and a drop in the pivot, renewed every few weeks, keeps moisture off the steel.

Dull Blade: How to Bring the Edge Back

A dull knife is slower, and it is more dangerous than a sharp one, because it takes more force and more force is what slips. Every edge dulls with use. The fix is a few minutes with the right tool at the right angle.

How to fix a dull blade:

1. Choose the tool. A bench stone gives the most control. A guided system makes the angle automatic. A ceramic rod is for touch-ups. Skip pull-through carbide sharpeners, which scrape steel off at a fixed angle and shorten a blade's life.
2. Set the angle. Every TEKTO blade is ground at about 20 degrees per side. Hold that and you refresh the existing edge instead of grinding a new one.
3. Sharpen. On a stone, draw the blade across as if slicing a thin layer off it, light and even, the same number of strokes per side, until a fine burr forms along the edge and then switches sides.
4. Hone. A few light passes on a ceramic rod or a strop remove the burr and align the edge.
5. Test. A sharp edge slices a sheet of paper cleanly from heel to tip without catching.

Preventing a dull blade:

• Hone, do not sharpen. A dozen passes on a rod after a day's use keeps the edge aligned and puts off real sharpening for months. Cut on wood or plastic, never on a plate or a metal bench, and keep the tip out of prying.

Rust and a dull edge are the two things that end most knives early, and neither has to. Clean it, oil it, hone it, store it dry, and a good knife outlasts its owner. Our sharpening guide covers the full method on a stone, a guided system and a rod, and the OTF cleaning guide covers the mechanism inside an automatic.