Bambi headliner woes

[bearcat]

you probably are thinking sagging headliner..Already been there and have fixed that to my satisfaction (actually looks better that before it sagged). I noticed a very black smudge on my ceiling recently and tried to use carpet cleaner to remove it..That seemed only to spread it....I was using a small vacumn to clean the headliner and I accidently rubbed against the headliner with the nozzle and that caused a black smudge like the first..I than noticed a similar smudge in the storage compartment..Something must have rubbed up against the carpet to cause this one.. I put the vacumn on the dark area that appeared and it seemed to at least make the area less dark indicating to me that it is coming thru the headliner, not liquid, and to some extent can be lessened by the vacumn as if it were black soot or something to do with the glue or foam under the carpet. anyone seen this happen or any ideas. I am afraid to touch the headliner now.This has nothing to do with the vacumn as the smudges were there before I ever thought of using the vacumn except for the one that appeared when I touched the ceiling with the vacumn.

[azflycaster]

Aluminum Oxide? On vintage trailers with exposed interior rivets you sometimes see black rings around the rivets.

[bearcat]

these smudges are irregular in shape and random. Not anywhere near screws. I am wondering if the glue or the foam material has turned into a power in places. As I said I merely touched a spot on the covering and it immediately turned black. That is the spot I put the vacumn near and it took some of the color away making it alittle less noticeable but still quite bad. I know that the glue was defective and caused the foam to break loose causing sagging but have not hear anyone mention this problem.