I used to sew my own canvas for my sailboat so I am very familiar with Sailrite. I am puzzled by your decision though. Sunbrella is a nice fabric but after about 5 years of UV exposure it requires frequent treatment, better if done even after year 3. Moreover, my vinyl tire covers get very dirty from splash during rain events. Sunbrella just does not clean as easily as vinyl. My conclusion was and still is to treat Walmart vinyl covers a disposable and when they are too ugly or used up, toss 'em and buy new ones. My first set lasted 3 years.