Acid rust removal

Acid rust removal is one of the more common ways of removing rust from a variety of surfaces. However, the acidity level depends on how long the rust stain has been allowed to form. For instance, basic rust stains can be removed with highly acidic foods while tougher stains might need phosphoric acid.

The most basic acid you can use for rust is in that of an onion or a lemon. These will get out minor surface stains on clothes and even guns. Lemon juice is usually used to get stains out of your bathroom, concrete, and other minor places. Vinegar may also be used and I prefer it because it is cheaper and slightly more powerful.

Metal parts soaking in acid with a bottle of primer awaiting them

If you have to use phosphoric acid you would use that on metals such as tools or industrial machinery. The acid removes the rust by converting it in to ferric phosphate. Phosphoric acid is also commonly marketed as a rust remover or a rust converter. The more popular naval jelly is a thick paste that can be applied to even vertical surfaces without dripping off. This makes it one of the more ideal rust removers on the market.

The last type of acidic rust remover to go over is hydrochloric acid. Sometimes called muriatic acid, it is another powerful chemical that can remove tough rust off metals or concrete. Even a diluted amount such as 15-19% can effectively remove rust from metals. Hydrochloric acid is sold in diluted forms as chlorine and can be found at a pool store.

Video demonstrates removing car rust with citric acid

This video shows how to remove rust on a large scale with acid.  First we begin by taking 3% citric acid and mixing it with water.  We let the metal soak in the acid for a day and removed it to scrub with a steel brush.  It was inserted back in to the drum of acid for another 24 hours and again scrubbed down with a steel brush.  We then pressure washed it to remove any further rust.  Lastly, we took a rag and rubbed gasoline on it to neutralize the acid and to protect it from rusting.

Be careful when removing rust with acid. Always wear eye protection because splashing can always happen. Do not inhale the fumes, doing so may cause lung irritation or breathing problems.