whats the best way to waterproof my canvas tent???? ive never had a prob with leaks before, the tent, granted, is very very old but still holds together and has many of memories. we had a rediculous storm yesterday that dumped over a inch of rain in 45 min, in se idaho thats unheard of. thankfully i had the tent up in back yard and noticed the leaks, no holes just came raight through the canvas. obviously it was raining very hard but nonetheless i wanna fix it. any ideas? thanks