1940 Buick 51

August 2022 - Fuel tank repair

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The original 1940 Buick fuel tank sat flush against the trunk floor. The water damage and rust on the trunk floor made its way to the top surface of the fuel tank and created rust holes. Ideally the easiest way would be to replace it with a new reproduction tank, but unfortunately at this time no one offers reproduction 1940 tanks. Also the size and shape of the fuel tanks are specific to 1940 and not used on any other year. Since tanks from other years are not easily interchangeable, I decided to repair the existing tank.

Several large holes are visible on the top of the tank.

After cleaning and stripping the tank exterior surface, I used a plumbing torch, solder and shaped pieces of copper to solder directly onto the steel to repair the holes. Pinholes were also soldered.

After applying the repairs, I cleaned and filled the tank with soapy water to identify more pinholes and leaks to plug as best as I could. Then I proceed to dry out the tank and seal it by sloshing a quart of Red Kote fuel tank liner inside the tank. After the liner cured, I did a final test by filling the tank with water to ensure there were no more leaks.

Finished tank with 2 part epoxy primer and black urethane paint applied with a HVLP sprayer.



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