Is any seam sealer applied on the inside of the engine compartment? I could not tell if old sealant had been removed or some spooged through from the wheel wells and the interior firewall. Same question for the lower portion of the rear wheel wells - is the sealer applied from just the outside or is some applied from the inside? I have already sealed on the inside where the upper well attaches to the trunk pan. This is for my 69 XR7.
What plant was your car built at. At all plants there would be the seam sealer over the pinch weld where the cowl and firewall come together. But for other applications it depends on plant and year.
There is also sealant applied to the firewall surface at and around items attached to or passing through the firewall. Product, pattern and details again depends on plant and time period
If we’re discussion just the seam sealer and not the sound deadener then yes it was typical for a worker to be assigned to seal the seam between the inner and outer wheel houses. On some years and plants there was also a brushed band of sealant around the outer wheel house to quarter panel joint though it was not really over the welds and appears not to be a useful application - but still done.
The type of product, the look and how it was applied in the trunk depended again on plant and year - or even narrower time periods and differed often, depending on what seam was being filled/sealed.
The car was built in San Jose. More concerned about properly sealing out moisture than concours application. Car has little original sealer in these locations so I cannot tell how and where it was applied.
Please remember that sealant can keep moisture out or keep it trapped in a seam. Lots of owners who spent money to undercoat their cars back in the day when these cars were new found that out the hard way. The car companies were focused on keeping the moisture/water from getting in the interior passenger areas ( ongoing complaints annually at the dealer meetings) that they tried to address often with thicker heavier applications.
I would suggest copying the seams Mercury focused on and leave it at that. Not sure that you plan on using your car as the first owner did or it will see more limited and sunny day exposure to the elements.
With that said at the firewall focus on the items that pass through the firewall and attach to it after the items have been installed before the engine is installed. Most owners can’t bring themselves to this as it appears messy and ugly. With that the firewall to cowl seam around the front and sides (cowl sides and a pillar areas) The front door jamb seams also and remember to reinstall the splash shields and gaskets.
At the rear seal the seal from the bottom of the inner and outer wheel houses. Then in the trunk from the top the wheel houses to the trunk floor on either side. This will allow any moisture that gets between the panels (pinch weld spot weld strip) a way down and out to drain if it every gets in the gap.
If you get interested in the factory look just post and should be able to post some pictures but since you stated that is not important to you I won’t at this time
Good luck with your choices
J_Speegle, Thank you for the education and information. The plan is to limit exposure to rain as much as possible and I will not be driving the car much as I live in Alaska and will keep the car in Washington state.
On the same subject, what is the proper “look” for the cowl to firewall sealer. Mine looks terrible and I’m going to redo it when the engine bay is painted.
For the 67 - 68 the cowl sealant is painted over in body color. Then the body color would have been masked off so the engine compartment black could be painted.
Like this:
So it’s just smoothed over and painted. I guess mine looks normal…
Sorry I just realized you were asking about 1969. I posted a photo of a '68. No idea if they are similar or not.
On a 69 the section from the firewall to cowl pinch weld up to and under the cowl cover was painted body color early in production than changed to an extension of the engine compartment black paint. So depends on when the car was painted at what plant.