Chris
My trailer is 16 months old and I have never done this....big mistake! My weather stripping (white), on the underside, is mildewed beyond repair. I wouldn't be surprised if the black streaks that appear below the window are from my neglect. I would never have known to go this in-depth had I not watched your video. Thank you, thank you, thank you :) I thought I was done with the cleaning until I found your video.
I have noted some owners have replaced the weather strip with a black one. Can anyone chime in where you can get it? Hope to se ya'll at the rally :)
John