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Shooting (seam sealer) in the hood

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  • Voyce
    Experienced
    • Oct 29 2022
    • 158

    Shooting (seam sealer) in the hood

    Had a hood nose cancer repair job on the Bird list.

    Upon removing the hood, one could really see the lost adhesion of the seam sealer disposed between the inner ribbed hood support stamping and the outer hood stamping. (After 60 years, you would lose some of your grip too.)


    However, the sealant had hardened to the point that in many, many spots it was only sticking to one side of the metal sandwich or the other. Worse, surface corrosion was starting to appear on the loose seam side. Then, there is the issue as to how much the lack of fully sealed frontal seams contributed to the nose cancer.

    So, out came the putty knife. Every old seam sealant was loosened, creating handfuls of hard sealant in all shapes and sizes, all conveniently stuck between the two stampings.

    So, out came the compressed air blaster. Much air, much turning, much grabbing, much fun?
    Now, time for the replacement seam sealant, an elastomeric urethane having a hard rubber functionality upon cure.

    So, out came the caulking gun. Tubes of sealant, circumferentially placed about all of the seam openings on the underside of the hood, using a solvent seam smoothing action:

    dataurl734613.jpg

    Luckily, the hood repair already put a repaint on the list. A few coats of color and a few coats of clearcoat:

    dataurl734612.jpg
    (Of course, the topside cancer was fixed, and it was repainted too.)

    Time to re-marry the hood and hinges. No more torsional movement between the stampings.

    dataurl734611.jpg
    Listen to that solid sound when the hood is closed!

    Who knew that shootin’ in the hood could be so rewarding?

    (No bystanders were injured in the restoration of this hood.)
  • simplyconnected
    Administrator
    • May 26 2009
    • 8811

    #2
    The factory didn't seal hemmed seams unless they potentially let water into the cabin, like cowl baffles that let air in. Spot welds are somewhat inhibited from going through sealer. They do however, put dollops of sealer between the inner and outer hood panels and 'door guard reinforcements' to eliminate sheet metal flutter. (when the car goes through the Sealer Deck). Primer Ovens cure the vinyl sealer before base coat is sprayed in 'Paint'. Back in the day, there was no such thing as clearcoat. So, you will notice that the sealer you removed was also painted.

    Nice job! Your hood is MUCH better than the factory job, now. Rust holes in the front of the hood are very common among all classic cars, especially in the North or places that get lots of rain. - Dave
    Member, Sons of the American Revolution

    CLICK HERE to see my custom hydraulic roller 390 FE build.

    "We've got to pause and ask ourselves: How much clean air do we need?"
    --Lee Iacocca

    From: Royal Oak, Michigan

    Comment

    • Dan Leavens
      Moderator / Administrator


      • Oct 4 2006
      • 6409

      #3
      Voyce great restoration on your hood. Well done. Regards
      Dano Calgary,Alberta Canada
      Thunderbird Registry
      58HT #33317
      60 HT (Sold )

      Comment

      • Voyce
        Experienced
        • Oct 29 2022
        • 158

        #4
        Dave:

        You are correct again. The old seam sealant was factory painted on its exposed faces.

        Thanks for the kind words.

        My main purpose in the above posting is to remind us all that no one at FoMoCo expected these Birds to be driven six decades later. I am confident that when the engineers selected the sealant material, they did not have that life cycle in mind. Nor did they have a moisture curing urethane available that remains flexible upon curing. A material that can absorb vibrational energy from the hood stampings.

        It sneaks up on you. Your hood seam sealant may not be doing its job anymore. With the hood removed, it was enlightening to see how much movement there was between the stampings due to the failure in the aging adhesion of the sealant. Once the repairs were made, then you could easily determine how much firmer the hood was, how much proper sealant adhesion assists hood functionality.

        So, to fellow stewards, think about checking out your Bird. How is your sealant doing “in the hood”?

        Dan:

        Thanks for the kind words.

        It was a lot of effort, but the reward lies in feeling and hearing the revitalized hood in action. It really sounds and feels different.

        One added detail I failed to mention can be seen in this image:
        dataurl965208.jpg
        We inserted rubber plugs in the row of holes in the lower stamping, at the front of the hood. Just gives it a more finished touch.

        Comment

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