Rust, or iron oxide, and rust stains can form on water pipes, bathroom or kitchen fixtures, metal pots, sinks and other hard surfaces. Rust can even stain fabrics when the two come into contact with one another. Not only does rust seem to appear out of nowhere, but it can quickly stain and corrode the affected areas and items. However, you can remove rust and rust stains with rust removal products or homemade rust removal solutions.
Scrape off flaky or loose rust, or as much rust as possible, from bare metal by using a stiff wire brush. If removing rust from previously painted metal, remove any cracked or peeling paint, strip the surface back to bare metal with a paint stripper and wipe clean.
Remove any dirt, oil or grease from the bare metal with turpentine.
Apply a generous amount of a rust removing solution made up of 2.5 per cent phosphoric acid, 2.5 per cent muriatic acid and one per cent 2-butoxyethanol to the bare metal. The phosphoric acid converts the rust into a black, water-soluble phosphate compound that you can easily scrub off, while the muriatic acid and 2-butoxyethanol simply dissolve and remove rust. You may need to use two or more coats if you're dealing with heavy rust.
Allow the rust removing solution to dry and scrub off any of the black, water-soluble phosphate compound left behind from the phosphoric acid.
Give the entire surface of the affected area a basic cleaning. Spray the entire surface with undiluted white vinegar and scrub the surface with a scrub brush.
Run a pumice stone, found in the beauty section of any supermarket, under warm water. Pumice stones are porous, so they will absorb water and soften, making them less likely to scratch the hard surface you are cleaning.
Scrub the rust stain with the dampened pumice stone using gentle pressure. The damp pumice stone may rub off onto the stained surface and leave a thin coating of a mud-like substance, but you can easily remove this coating by rinsing the area with water or wiping it off with your fingers or a rag.
Check your progress throughout the stain removal process by running water over the rusted area. This will wash away removed rust and rinse off any coating rubbed off from the pumice stone so that you can fully see your progress. Continue scrubbing and rinsing until the rust stain disappears, then give the area a last thorough rinse.
Lay the rust-stained fabric out flat over a clean surface or on top of some paper towels.
Use lemon juice or white vinegar to remove the stain. Both contain acid, which dissolves rust. While most rust removal products also contain acid, their high acidity can damage your fabrics, so gently acidic solutions made of lemon juice or white vinegar are safer on your fabrics.
Squeeze the lemon juice or gently pour the white vinegar over the rust stain just until the area is soaked through. If using lemon juice, you can also cover the rust stain with table salt before squeezing lemon juice onto the stain.
Allow the fabric to dry outside in the sun or to sit for at least 30 minutes if drying the fabric indoors. Rinse the fabric with cold water once it's dry and hand wash or wash normally in the washing machine, depending on the fabric and its care instructions.
Avoid using any form of acid, even lemon juice and white vinegar, on delicate fabrics. Always perform a spot test on a hidden section of the fabric to make sure the acid in the lemon juice or white vinegar does not damage the fabric.
Muriatic acid is a highly toxic acid that can cause severe burns in its highly concentrated form. However, muriatic acid is safe in its highly diluted form, so make sure that your rust removing solution contains no more than 2.5 per cent of muriatic acid and uses muriatic acid in its highly diluted form). Do not use chlorine bleach or products containing bleach to remove rust stains, as chlorine bleach can make rust stains worse.