De-rust tank with citric acid


When it comes to rusting the inside of a tank, you should always use the appropriate type of de-icing. If you want to do the de-rusting yourself, it's best done chemically. Citric acid has been well proven in tanks of moped and motorcycle. Why this is so, and how to proceed best, you can read here.

Citric acid as a de-rusting agent

In principle, all strong acids can be used for de-rusting metal. Citric acid has some advantages over other acids:

  • It is still effective, but relatively harmless (compared to hydrochloric acid, for example)
  • It can be procured easily and inexpensively (in powder form in every shop)
  • The remains can be disposed of relatively safely (which is not the case with hydrochloric acid, for example)

If the rust inside the tank is not too strong, citric acid is a good choice. Also Essigessenz would be a possibility, but often too less effective.

Other harmless possibilities

Somewhat more effective than citric acid, and equally harmless is oxalic acid. It is also known as clover acid from time immemorial. In order to reduce the dangers of the acid even further, the same effective clover salt can be used instead.

Important when derusting

On some things you have to pay attention while derusting in any case. If you rust yourself, you should first convince yourself of the extent of rust damage inside. If the tank already threatens to rust, it must be welded by the professional. De-rusting then brings nothing more.

Remove tank and seal

If you build the tank on the motorcycle, you have to make sure that you also dismantled fuel gauge, fuel cock and the fuel cap. The outlet openings must be sealed in any case. This is best done with latex gloves. They are also acid resistant.

For tanks of other vehicles, the same applies.

Distribute acid in the tank

In order for the acid to be able to act on all sides inside the tank, the tank must be turned from one side to the other at regular intervals. Only partial rust removal is worse than no rust.

Rinse and seal

After de-rusting, the tank must be thoroughly rinsed. Since rusted metal parts are very sensitive to corrosion, they should be treated as soon as possible.

Phosphoric acid acts as a rust converter and also gives the metal a protective layer. Thereafter, a seal should be envisaged. There are finished products in the trade.

Tips & Tricks

It is certainly worthwhile in most cases to have this complex and time-consuming work done by a professional. For motorcycle tanks costs from 150 EUR including sealing required. But then the work is done perfectly. Damaged tanks are also repaired.


Video Board: Rust Removal Experiments: Citric Acid, Cider Vinegar, Rostio