Originally Posted by maggiemae
Hallelujah, we're finally at this point, too!
So you have to Remove this stuff to see if there is rust underneath? Won't the rust just visibly come through?
I'm guessing this stuff is some type of sealant?
The stuff on mine is tar-like. It's still a little soft and pliable even after all these years, which is why I didn't really consider sanding to remove it (thinking the paper would just clog with this stuff). It is not applied very evenly -- some places are very thin and dried before they could grab the fiberglass at all; other places are thicker and have a lot of fiberglass stuck in them (another reason not to sand). My guess is that its purpose is to absorb sound, but not very well, and to adhere the fiberglass in place.
As thin as it is I would think any rust would show through. I'm planning to clean up the middle area of each section and not worry about the edges with the hope that foam will adhere well enough to keep itself in place. We'll see how that goes.