Noticed the back of our calves, around the Achilles tendon, were getting greasy black marks whenever we used our Airstream. Traced it to the area around the door threshold - back of leg would rub as we exited the trailer.
Found bottom edge of door rubbed door frame - wearing into it and causing the worn aluminum to mix with road grime and make a greasy black paste.
Door has been adjusted twice by the dealer to correct fit and closure issues, so thought I'd deal with this myself. First cleaned the affected area with brake parts cleaner. Then installed a 27½" strip of vinyl edging I found in the basement. I glued it on with clear RTV. It fit well, though weatherstripping or a piece of rubber or clear vinyl tubing slit lengthwise would work too
This is what I used:
https://www.homedepot.com/p/COL-MET-...5VTC/202205239
Doorway
Closeup of threshold showing worn area
Plastic edging trim on door edge
So far so good...
As an alternative I could have ground the door bottom with the Dremel, but this repair is easily reversible if it doesn't work, whereas grinding metal away would not be.