I had a tear in my boat canvas. Someone tore it trying to come aboard without unsnapping it!
So I took Bee’s Knees Zipper Wax and rubbed it on either side of the tear on the outside and the inside.
Then I took some heavy duty sewing thread and coated that with BKZW. Threaded the needle and made the repair.
When I was done I re-coated the outside and inside at the repair site with BKZW. That was 2.5 years ago… the repair is stronger than ever, and it is 10X as water repellant ans untreated canvas… BKZW is Amazing!