At 19 years, the canvas from the orig Zipdee's leaked like a siv. Went to my favorite rv supply and asked what to use? They sold me a product call Canvak. A gallon was $26. and when sprayed with a garden spraver covered all the awnings, Main, rear windows and driver side. The stuff worked great, they all shed water like a duck! My next door neihbor said he had used Thompsons deck water seal on his boat canvas and kept his canvas good for years. Stayed water tight until last year when I replaced all the canvas due to old seams falling apart, but still repelled water until the end.