Closed cell expanding foam, For all those nooks and cranys that collect road grime Options

[tbox56]

I have been working on a little bit of rustoration on my 72 subie conversion, and found a couple of areas that have some of the dreaded 'rust bunnies'. One of these is just behind the doors, just on the inside of the vent tube, and the other is by the taillights on toward the outside of the car. after looking at and repairing these areas, i think that the best way to protect them is to keep all of the road grime and moisture out. My thought was to take some 2 part expanding closed cell foam and fill these spots. I found three products on 3M's website that look like they would work. Does anyone have any experience with these products? Foams and NVH

Thanks in advance
Thomas

[tbox56]

I understand that done improperly the foam can act like a sponge, however all of the foam in the car is 38 years old, and seems to have done a pretty good job. On my car i have one corner that still has the factory foam in it, and one that it was removed to replace the fender a number of years ago. The one that was replaced is now full of road grime, sand, pebbles and the like, and beginning to rust, while the factory foam is still rust free and solid.. It would seem to me that done properly, and sealed, i would be miles ahead of a bunch of sand in that corner.

Further thoughts?