This door is under a covered patio which creates the mystery about the staining.
Wind driven rain or a poorly aimed sprinkler head maybe. Who knows.
Some companies offer mods to plain doors where they cut out a section and add glass. The caulk used around that insert must be oozing out and collecting dirt.
That must be it Bruce, because there is no water source nearby, and the door is set back a good 10 to 12 feet from the patio edge. Thanks
Thats would be my guess too.
Heat!
That is the glazing compound from the window coming out.
Guess your mind works a little different depending on what part of the country you are from. I wouldn’t have though of caulk, glue, or glazing oozing out when I looked at the picture quickly.
I’ve sold doors in the past where the homeowner would take the glass and frame out of the door in order to paint it (guess tape was too hard), thus ruining the factory sealant. They would then use any caulk to try to reseal it, either heat would make it ooze back out or moisture got into it, and if it was steel, it would rust.
EXACTLY—:roll:
What chemicals have they been using to clean the windows and doors?
Glazing compound–:))
I’ll guess dirty ones, from the photos #-o
Heat?? In Arizona?? C’mon!! 
It was actually a cool one today. Only low hundreds. nice rain right now though.