How to Remove Rust from Metal? Home and Mechanical Methods

Step by step

1. 1

   Assess the corrosion and gear up

   Judge how deep the corrosion goes, because a light surface film will come off with home methods, while thick, flaking rust needs mechanical abrasion. Also check whether the item can be dismantled and submerged, or has to be cleaned in place. Work in gloves and goggles, especially with acids and wire brushes.

2. 2

   Submerge the item in vinegar

   White vinegar at around 10% dissolves rust effortlessly, so put the rusty piece in a bowl and cover it completely. Keep small items in for 8-12 hours, and heavily corroded ones for up to a day, checking the progress from time to time. After taking it out, scrub off the softened deposit with a brush or the rough side of a sponge and rinse with water.

3. 3

   Use citric acid

   Dissolve 3-4 tablespoons of citric acid in a liter of warm water and submerge the item for a few hours. Citric acid works more gently than strong rust removers, so it suits more delicate parts and small tools well. The solution fizzes lightly around the rust, which shows the reaction is working.

4. 4

   Make a baking soda paste for light rust

   For a light film, make a paste of baking soda and water with the consistency of a thick slurry and apply it to the rusty spots. Leave it for 1-2 hours, then scrub with a small brush or a rough sponge. It's a handy method wherever you can't submerge the whole item in a bath.

5. 5

   Rub spots away with a potato and dish soap

   You can rub thin rust spots away with a halved raw potato: coat the cut side with dish soap and rub the corroded points with it. The oxalic acid in the potato helps dissolve the deposit, for example on knives or scissors. This trick works on small spots, not on a thick, old layer of rust. After a few minutes rinse and dry the metal.

6. 6

   Grind off thick rust mechanically

   Take a thick, flaking layer off first with a wire brush, then smooth the surface with sandpaper, starting at 80-120 grit and finishing at 240-400. For what's left in crevices use fine 0000-grade steel wool. Work along the surface and collect the dust as you go, so you don't rub it back in.

Phosphoric acid rust removers - when to reach for them

When the rust is extensive or home methods can't cope, reach for a rust remover based on phosphoric acid. Such a product doesn't just dissolve corrosion; it converts it into a layer of phosphates that makes a good base for paint. It works well on gates, tools, car parts and larger structures.

Apply the product with a brush or sponge and wait as long as the packaging says, usually from 15 minutes to a few hours. Work in gloves, goggles and a ventilated room, because phosphoric acid is caustic. When you're done, wash off or neutralize the surface exactly as the manufacturer recommends.

How to protect metal after removing rust

Freshly cleaned metal rusts faster than new, so dry it immediately, first with a cloth, then with a hair dryer or in a warm, dry spot. Moisture lingering in crevices and on edges kicks off corrosion within hours. Don't put off the protective coat, or all the work will go to waste.

Wipe tools and everyday items with a thin layer of oil, machine or food-grade depending on the use. Cover parts destined for painting with an anti-rust primer first, and only then with a topcoat. Check oiled tools from time to time and renew the oil layer after heavy use. Stainless steel surfaces just need polishing and keeping dry.

Frequently asked questions