3M's 303 High Tech Fabric Guard works best of all of the products that
we've tried. You need to use a 1 gallon pressurized sprayer to get an even
coat otherwise you can get rings. The Starbright Water Proofer works well
too, but we think that the 3M product might repel dirt a little more.

-- Geoff

Jerry wrote in :

My sombrella cloth dodger is beginning to show signs of ageing. It
leaks a little over the companionway when it rains. I tried Scotchguard
but it does not help much. Anybody know of a product or treatment that
will work better and let me get a few more years out of this dodger?