Gas tank "restoration"/underside of trunk

Discussion in 'Chassis restoration' started by Barsteel, Apr 22, 2020.

  1. Barsteel

    Barsteel Well-Known Member

    Hello!

    This is my first post in the restoration forum, and I'm still relatively new on this board.

    I recently added a '71 GS Stage 1 4spd car to the collection. It's unrestored, running, and driving car, but it definitely needs some love, mostly interior work.

    Anyway, my first task is to get all of the gauges working, starting with the fuel gauge. I already dropped the tank and found that I had a bad sending unit, and that the gauge still works. The tank itself is solid, ie no leaks, but it does have some surface rust on the top surface, where it touches the underside of the trunk floor.

    What is the best way to "restore", or at least clean up the gas tank? Normally, I'd hit any rusty metal with a grinder, treat it with phosphoric acid, then prime and paint it, but that creates sparks, the tank still has gas fumes in it, and I'm not in the mood for blowing myself up at the moment.

    The underside of trunk has some surface rust as well, so I plan to grind/treat/paint it. I've read that earlier cars were painted semi-gloss black; Is that what I should use for my car?

    Lastly, the tank appears to have been undercoated after it was installed. Were tanks undercoated at the factory, or just painted black?

    Thanks...

    Chris
    Monroe, CT
     
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  2. telriv

    telriv Founders Club Member

    Usually the top of the tanks were unpainted. The bottoms could be natural or under coated at the dealer at time of new car prep. Prep the top of the tank as you normally would & prime & paint. I would rather use a wire brush to clean. The tank material is very thin. Same with the underside of the trunk floor.
    IF your afraid of sparks run an exhaust pipe of an older car without a cat with a rubber hose & direct it into the tank for 15-20 minutes. Will get rid of the fumes.
    AND, there are a few people on this forum that live in or close to Monroe.
     
  3. Barsteel

    Barsteel Well-Known Member

    Tom - Thanks for the reply. I've been told that there are several Buick guys in Monroe. I just bought my GS a few months ago and just started digging into it, so I haven't tried to get in touch with anyone yet. At this point, I'd like to get everything working, get a correct carb for it, and get it running 100%. The engine is newly rebuilt and runs very well, but the carb is missing some of the linkage, so if I try to kick in the secondaries, it just sputters.

    The biggest job for me will be the rust holes in the dash. I'll have to pull the windshield and see what I'm dealing with. The rest of the car is solid, so hopefully nothing horrible.

    Chris
     
  4. CJay

    CJay Supercar owner Staff Member

    I would just bite the bullet and buy new Spectra Premium tank. They're plated in Terne like the originals and look awesome. Why mess around with a rusty tank?
     
  5. CJay

    CJay Supercar owner Staff Member

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