I finally got around to pulling the seats, console and carpet in my 68 Cutlass convertible to see what needs to be done to the floor.

Luckily, there are no holes and nothing more than a little surface rust. Pretty good for a 55 year old convertible. I plan to wire brush the rust, use a rust neutralizer and paint it with Rust-oleum unless you guys have a better idea.

My question for you is:
When I vacuumed all of the rust and debris, I picked up a lot of black plastic-y material that came from around the seat bolts and maybe some of the floor seams. Was this some sort of factory sealant? Do I need to reapply sealant to any of these areas? You can see some of what remains in the photos below.

 

That's sealer and sound deadener. Brush-on seam sealer is used anywhere there are factory lap joints in panels. In addition. sound deadener (sometimes called "dum-dum") was applied to panels and also where brackets like seat mounting brackets lapped over panels to deaden squeaks.

 

Thanks, Joe! Is there a modern version you’d recommend using?

 

There are a number of good two-part epoxy seam sealer products today. I like 3M brand, but there are others that are equally good. Note that this dispenser pack requires a "double barrel" caulking gun for application. If you don't want to deal with that, 3M also sells one-part brush-on seam sealer that is equivalent to the OEM stuff.

 

Sounds easy enough. Many thanks!