I might still have an Electrolux spray thing boxed somewhere. When I was a kid in the 60's, dad waterproofed our canvas pop-up trailer with it.

1957 Chevrolet 5700 LCF 283 SM420 2 speed rear, 1955 IH 300U T/A, 1978 Corvette 350 auto, 1978 Yamaha DT175, 1999 Harley Davidson Softail Fat Boy