1967 GT 350 (Early 10/66) Fiberglass Tail Panel Installation Details

[DGSOH]

My understanding is these panels were installed with dum-dum between it and the original steel panel with a clear silicone bead around the outer edge and fuel filler/trunk lock opening. Can anyone share more about how this was/is done i.e. application, appearance, etc.? Pictures are always helpful too hint, hint.

Many thanks -

DGSOH

[JD]

If you're having the car judged, the originals used the strip caulk (a lot of it) all around the full perimeter of the panel.  Also every gap and opening!

If you're trying to keep the fumes and water out then, some have used a variety of things including expanding foam on the larger gaps.  But I've heard of guys going overboard with that stuff I guess it REALLY expands and you need to watch/work with it until it stops expanding.

Smaller gaps, around the tail light lenses and aluminum frames can be filled with CRYSTAL CLEAR silicone (the clear stuff is not really clear).

Goes a long way to sealing out the exhaust fumes!

[BGlover67]

If you're having the car judged, the originals used the strip caulk (a lot of it) all around the full perimeter of the panel.  Also every gap and opening!

If you're trying to keep the fumes and water out then, some have used a variety of things including expanding foam on the larger gaps.  But I've heard of guys going overboard with that stuff I guess it REALLY expands and you need to watch/work with it until it stops expanding.

Smaller gaps, around the tail light lenses and aluminum frames can be filled with CRYSTAL CLEAR silicone (the clear stuff is not really clear).

Goes a long way to sealing out the exhaust fumes!

Listen to JD on this one, he did a great job on sealing out the fumes on 26.  I never noticed any oder, while with 83, I thought my son was going to need an oxygen tank after going for a ride in the backseat!   

[Bob Gaines]

My understanding is these panels were installed with dum-dum between it and the original steel panel with a clear silicone bead around the outer edge and fuel filler/trunk lock opening. Can anyone share more about how this was/is done i.e. application, appearance, etc.? Pictures are always helpful too hint, hint.

Many thanks -

DGSOH

For a historically correct looking appearance is that you try not have any clear silicone visible because it wasn't typically used in this area like it was in others. For a pleasure driven car you need to have the tailpanel sealed tight like JD described. Gas filler neck and even around trim rings are especially susceptible leaky areas as mentioned. Trying to get the look while sealing is the challenge. 

[Shelby_r_b]

If you're having the car judged, the originals used the strip caulk (a lot of it) all around the full perimeter of the panel.  Also every gap and opening!

If you're trying to keep the fumes and water out then, some have used a variety of things including expanding foam on the larger gaps.  But I've heard of guys going overboard with that stuff I guess it REALLY expands and you need to watch/work with it until it stops expanding.

Smaller gaps, around the tail light lenses and aluminum frames can be filled with CRYSTAL CLEAR silicone (the clear stuff is not really clear).

Goes a long way to sealing out the exhaust fumes!

++++1. JD is spot on as usual.

[DGSOH]

Thanks to all. I was confused on the silicone aspect.

Was there a TSB on this and if so does someone have a digital copy?

I want it all Bob, period correct appearance with modern utility : ) so my approach is always to first understand what is correct and deviate only when there's a good reason to do so, sometimes one or the other suffers. The expanding foam solution JD mentioned I think over emphasizes utility... too extreme for my taste, I'd rather get gassed.

Thanks again

[roddster]

  My opinion:  The crutial areas are above and below the curved sections of the four stud mounts.  Dum-dum is good, but you can also use that spray foam with a light-easy touch on the trigger.
  Too bad the old forum is gone.  There was extensive photos about this in it.

[DGSOH]

As far as using strip caulk, do we think it was applied prior to installation of the panel or after the fact, or maybe some combination of both?

[Bob Gaines]

As far as using strip caulk, do we think it was applied prior to installation of the panel or after the fact, or maybe some combination of both?

Typically installed before installation. Evidence of the process on survivor cars confirm the process. Informed concours judges look for the correct installation process.  That same squeezed out look of the strip caulk is hard to replicate when trying to install strip caulk after the fact.

[DGSOH]

As far as using strip caulk, do we think it was applied prior to installation of the panel or after the fact, or maybe some combination of both?

Typically installed before installation. Evidence of the process on survivor cars confirm the process. Informed concours judges look for the correct installation process.  That same squeezed out look of the strip caulk is hard to replicate when trying to install strip caulk after the fact.

Thanks Bob.

That's what I was thinking but wanted to be sure. Do we think it was applied to the panel, the body or both before setting the panel in place? Or maybe it varies depending on the amount of gap to fill? My guess, at least for the outer edges, it would have been applied to the panel or maybe that's something that can't be known for certain 50+ years on?

[Shelby_r_b]

As far as using strip caulk, do we think it was applied prior to installation of the panel or after the fact, or maybe some combination of both?

Typically installed before installation. Evidence of the process on survivor cars confirm the process. Informed concours judges look for the correct installation process.  That same squeezed out look of the strip caulk is hard to replicate when trying to install strip caulk after the fact.

+1.  I had to re-remove the tail panel on 0022 in order to apply the strip caulk appropriately.  It wasn't hard, and well worth it - both from a looks and functional perspective.