Rust in the tank - what can you do about it??

Tanks can become dirty and rusty over the years. This article explains what specifically leads to this, how to avoid rust formation inside the tank. In this article you will also find out what options there are to derust rusted tanks and repair rusted tanks.

Formation of rust in the tank

The most important factor in the formation of rust in tanks is the ethanol contained in the fuel. Ethanol attracts moisture. This mainly happens when the vehicle or motorcycle is stationary for a long time and is not moved. Modern fuels contain even more ethanol than in earlier times.

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The moisture in the tank when standing causes the inside of the tank to slowly corrode. On the outside, the tank can still look rust-free.

In classic cars that have been standing for decades, the remaining gasoline inside turns into a tough, tar-shaped mass. These dimensions, if not removed, can also cause engine damage and piston seizure when used for the first time.

Prevent rust formation

For motorcycles that are in the garage in winter and for vintage cars, the advice to always leave the vehicle with a full tank is quite controversial. The ethanol can attract even more moisture, especially when the tank is full. When the tank is empty, however, the residual moisture can also be responsible for corrosion. So good advice is expensive here. There is no magic formula.

Remove the rust in the tank yourself

In principle, this is possible, but it is not advisable in severe cases. Strong acids such as hydrochloric acid (€ 6.95 on Amazon *) and phosphoric acid are usually used to remove rust. The residues of the acids are toxic waste that is difficult to dispose of yourself.

There is also the risk of uneven rust removal and a high risk of injury. If you want to remove rust from your tank yourself, it is best to use oxalic acid.

Have the rust removed from the tank

For motorcycle tanks in particular, there are a number of specialists who take on rust removal and renovation at relatively low cost. For the motorcycle tank this usually costs from around 130 - 150 EUR including sealing. The benefits usually include:

  • complete internal cleaning of the tank
  • Complete derusting of the inside of the tank
  • complete sealing of the inside
  • Repairs (welding) in the event of rust perforation or near-rust perforation

Having the tank professionally derusted and sealed is therefore worthwhile in most cases.

Tips & Tricks If you want to remove rust from the tank with oxalic acid, it is best to use 10% acid. The paint is then also not attacked.