Forgot a pot in the sink? Don't let rust spoil your day, or your sink. Try these no-fail methods to remove rust.

Rust stains can sometimes be removed from concrete by scrubbing with a solution of four ounces of oxalic acid in a quart of water. Oxalic acid is sold in crystal or powder form at paint stores.

A: Oxalic acid is a potent but toxic cleaner that removes rust and stains caused by iron, water and tannic acid. It's available in dry crystal form, to be dissolved in warm water for use.

Rub With a Raw Potato Potatoes contain oxalic acid, which converts rust into a water-soluble salt that dissolves in water and easily rinses away.

Found naturally in rhubarb and other vegetables such as spinach, oxalic acid attacks stubborn rust, tarnish and lime stains at the molecular level, breaking the bonds that hold them together.

Choose an out-of-the-way spot in case the acid does damage the sheen. What about using oxalic acid outdoors to clean rust from vinyl siding, brick, mortar, concrete and so forth?

After this victory, I went to the garage to see if the oxalic acid would remove harsh rust stains left on the concrete floor from the bottom of my snowblower.

A: Rust stains on concrete seem to respond best to acids of various types. The classic treatment is oxalic acid, which is sold at some paint stores for use as a wood bleach.

According to Future Market Insights, the oxalic acid market is projected to grow from USD 1 billion in 2025 to USD 1.7 ...

This is because the rust can soak into these surfaces. You just have to be very patient and try to work in the shade so the oxalic acid solution doesn’t evaporate.