Most old motorcycle tanks after 30 plus years of use, neglect, or abuse end up in pretty sad shape. Bringing a fuel tank back to usable or  show quality condition, requires several steps.
We recommend sealing the tank with epoxy sealer designed for fuel tanks, after cleaning to protect it from rusting again.

First you will have to decide if the tank will be painted or powder coated. If powder coating, clean the tank but wait until it is back from the powder coater to do the epoxy coating. Otherwise, the Epoxy coating will be destroyed when the tank is heated for powder coating.
If using automotive paints, the tank interior should be completely cleaned and epoxy coated before painting.
Cleaned and Powdercoated Tank for CT90 K1
Chemicals needed for Fuel tank restoration


Please note that some of the chemicals required for cleaning are very toxic, can and will cause severe bodily injury if not used properly.  For your safety, please read and follow proper safety guidelines/instruction as listed by the manufacturers. Always use eye protection. Always work in a well lighted and well ventilated area away from open flames, or spark sources.
Always dispose used chemicals according to local codes, and above all, use common sense.
If you have never used, or are not comfortable using these chemicals, please don't attempt this restoration.
Please use the guidelines at your own risk. This site, myself, or anybody else, will not be responsible for any damage, injury, and or property loss, resulting from the use of any methods and or chemicals listed on this website.  
Thank you.

List of items needed:

  • Chemical resistant GLOVES
  • LONG SELEVE SHIRT to avoid skin contact with chemicals
  • At least two waste containers to keep acid and other chemicals seperate
  • 10-15  METAL NUTS
  • OXYSOLV (coats the bare metal with a rust resistant phosphate coating)
Tank Cleaning and Relining:

STEP  1:
  • Use old tubing to plug both tank outlets.
  • If your tank has been powder coated or painted already, use painters masking tape to carefully and completely mask the area around the tank opening. These chemicals can and will RUIN your new finish.
  • Make about one Gallon, 25% mixture of Muriatic acid with water and pour about a quart of the mixture into the rusty tank. Throw the metal nuts in and use an old fuel cap to cap the tank. Make sure you keep track of how many nuts you put in the tank, so you can get the same number out!
  • Now aggressively shake the tank and use the metal nuts to get in all the corners of the tank.
  • Carefully open the tank cap and pour the dirty acid mix into a waste container.
  • Repeat until all the rust is gone. Should take about three to four times.

  • Make a mixture of Baking Soda and water about  18oz. 
  • Pour half of the mixture into the tank and  shake the tank with the fuel cap on.
  • Repeated again. This is to neutralize the acid bath used earlier.

  • Pour about 12oz of OxySolv into the tank and cap the tank. 
  • Move the liquid around the tank. Check periodically through the opening with a flash light. You are looking for a uniform GRAY appearance/coating on the inside of the tank. This process usually takes about an hour.
  • After the tank has a nice uniform Gray Phosphate coating, drain the Oxysolv, you can use the original container. This stuff is reusable at least twice!

  • Pour about 8 to 10oz of Acetone into the tank and with the cap on, move the tank to cover/reach all of the interior areas of the tank. You can drain the acetone back into the original container or a waste container for disposal.

  • Pour about half (8oz) of the Gas Tank Sealer liquid into the tank. Cap the tank and slosh the liquid around, making sure it covers all of the inside of the tank.
  • Uncap periodically to check the progress.
  • After you are satisfied with the coating, use the fuel tank reserve outlet to drain the sealer liquid back into the original container. This can also be used again ! It is impossible to drain all the coating liquid out of the tank.
  • Let the tank sit upright. You may have to move it around to spread the excess liquid around the fuel tank.
  • The coating will cure in about 24 hours and you will have a worry free fuel tank for a long time.

Fuel Tank Restoration