When buying a vintage motorcycle you will be easily confronted with a tank that is completely rusted inside. Do not worry, there is a very cheap solution: You can easily remove the rust in your tank with electrolysis! How to remove rust from a motorcycle tank?
What do you need?
A rusted tank
A direct current source (DC) (battery, …)
A piece of electric cable
Soda (ordinary baking soda, NaHCO3)
A wooden board
A piece of metal.
400 grams of citric acid
Coating or 2-stroke oil
Step by step, just follow these steps: Find a DC power source. This can be an ordinary DC charger for batteries (like in the example) but also just an ordinary battery. You can also use another charger, but use preferably a 12V DC charger.
Secure the cable to the positive (red) and negative (black) of the DC charger or battery. If you use another 12V charger, you have to strip the wires. Make sure that you have at least a DC charger.
Take the board and the piece of iron. Nota that the piece of iron can not be used anymore after the electrolysis.
Make a hole in the board and attach the piece of iron so that it is stable.
Dissolve 100 grams of soda in warm water. Fill the tank with the soda solute and plain water up to the brim.
Put the tank on a couple of wooden blocks, or on another non-conductive basis (wooden table, reversed wooden box like in the example).
Put the piece of iron in the tank. Make sure that the piece is as far as possible inside the tank, without hitting the metal of the tank! Otherwise, you will have a short circuit! When everything is attached, tape everything securely so that your piece of iron or board can not move anymore and accidentally cause short circuit during the electrolysis. Make sure that the board ‘floats’ above the tank, so that junk or water can come out during the electrolysis. Connect the positive cable to the piece of iron in the board . Connect the negative cable to the tank, making sure that the area where you connect the wire is not painted. Warning: the gas the electrolysis produces is explosive, do this outside or in a well ventilated area!
Everything is ready now. You can turn on the charger. You can choose how many volts (use at least 12 V). The more amperes, the faster it goes . I used about 1 ampere. After an hour, you should already see results. After one day you should see more results …
Depending on how rusted your tank was, the process will need more or less than 24 hours. If you think you’re ready, you can let the water run. The rust has been completely attached to the piece of iron or it has been converted into a black precipitate inside the tank.
Fill the tank completely with water, add 400 grams of citric acid (for a tank of 15 liters). You can also use another acid, but citric acid is good for the environment and works fine! You can also use vinegar: for example you can fill the tank with 3/4 vinegar and 1/4 water. Let it rest for at least 24 hours. Flush the tank thoroughly with water. Please note that your tank will immediately begin to rust again. So you should start applying a coating or half a liter two stroke oil as soon as possible after rinsing, so that your tank is protected again. The difference between before and after is impressive! This method is easy and won’t cost you a cent. Good luck!