Published – May 14, 2011

Author – admin

Category –

Comments – 7

The tank on my 550 looks clean from the outside but it had a lot ofcrusty rust inside. I’ve used muriatic acid to clean tanks beforebut I wanted to try another method. So, I talked to my buddy Ryanwho is a material scientist of sorts for a living and he gave methe run down of how to do electrolysis to remove rust.





electrical tape

DC power

Tape the petcock shut.

Dilute roughly 2 cups of salt in water and pour it in the tank andcontinue filling the tank until it’s almost full.

Connect the positive to the tank and the negative to the metal barand cook it between 6 AMPs and 8 AMPs for 30 to 45 minutes. If it’stoo low in AMP’s add more salt and if it’s too much dilute themixture.

This process worked great for removing the chunky rust so I suggestdoing this and then a quick acid wash to finish the job.


  1. Richard says:

    05/15/2011 at 12:05 am

    Looks like a fun science project. Does that battery charger have anammeter on it or did you connect one in-line to determine youramperage?

  2. mick says:

    05/15/2011 at 9:23 am

    where on the tank does the positive attach to? anywhere?

  3. andrew says:

    05/15/2011 at 9:57 am

    positive to the metal rod… negative to the tank. Great trick!

  4. Adam says:

    05/15/2011 at 11:16 pm

    The battery charger had an ampmeter on it.

    I scraped a little bit of paint off of the tank lip that fits intothe rubber mount just infront of the seat and attached the positivethere.

    The positive should be attached to the tank and the negative to therod because electricity flows from positive to negative and I wouldthink that’d be the logical way you would want the currentflowing…

  5. KevanK says:

    06/10/2011 at 9:13 am

    Did you seal the tank after the acid wash? If so, what did you use?Any flash rust problems?

  6. Patrick says:

    02/19/2013 at 10:24 pm

    I have a 1973 Honda CB350 that is going to get this treatment inthe spring. I used a similar method to remove rust from some partslast year, but I used washing soda (sodium carbonate) instead ofsalt. For the DC power source, a battery charger works well.

    Instead of muriatic acid, I plan to use phosphoric acid to wash outthe tank. Phosphoric acid will react with any remaining rust in thetank to form iron phosphate, which forms a neutral, passive layerthat protects the underlying metal from further rust.

  7. Patrick says:

    02/19/2013 at 10:30 pm

    Oh, and don’t let the iron rod/bar touch the tank itself. it has tosit in the liquid but not touch the metal, otherwise the currentwill simply flow through the metal of the tank itself between thenegative and positive connections. The current has to flow betweenthe tank and the bar through the electrolyte (liquid). The bar willget a covering of rust in the process.

    An advantage of using washing soda instead of salt is that yuou candump the solution in the garden when you are done, it won’t harmanything.

    One more caution.. this process works for the inside of gas tanks,and ordinary iron or steel parts in a solution bath. it does notwork well for stainless steel. And DO NOT use it for chromed parts,unless you like handling carcinogenic chromates in the usedsolution (which are classed as toxic, hazardous waste).