During a few hard rains we have noticed our awning is leaking where the thread has sewn the end attached to the camper. I’m thing of putting some of he self leveling compound along the length of the seam since it doesn’t completely harden.
How about something like Starbrite waterproofing spray?
Or maybe waterproofing spray made for clothing or leather?
Maybe even a light spray of clear polyurethane along the seam?