I know we have talked about this in the past, I have also used several different products in the past ranging from WalMart fabric waterproofer to 3M outdoor fabric Scotchguard.

This past spring I got the 303 Fabric Guard recommended by Sunbrella and did the bimini and mainsail cover. The 303 stuff is pricey, about twice the price of the Scotchguard, 4-5 times the price of the Walmart stuff. I noticed first off that it did not have the overwhelming chemical smell when I applied it. The Walmart waterproofer and the CampDry brands are very strong, after applying once to fabric in my workshop I was told by the admiral that would never happen again, or else. I found both of those products to be decent, but did not last the season. The HD outdoor Scotchguard was less pricey than the 303, not quite as smelly as the cheaper brands but also did not last as long as the cheap ones. The 303, although recommended by Sunbrella, did not provide the water proofing that the cheap stuff did, and absolutely did not last the season. I can't say that I can justify the price unless there is something I'm missing like UV protection or something?

This past weekend I was wondering through a small home improvement store by the house and saw a new (to me) product from Thompson's Waterseal for fabric. It is supposed to provide UV protection as well. The price was $7 a can which is less than 1/2 that of 303 a little less than scotchguard, about twice that of the Walmart brand. I picked up a couple of cans and plan to give it a try. I got the mainsail cover done Sunday and will do the bimini once I repair some of the stitching, I'm curious how it will work out. The smell was about the same as the 303 by the way.