No
The air dry stuff just doesn't get hard enough, IMHO. Using two part urethane and epoxies does not stop you brush applying,(probably worth doing on a small job like boards where you want A lot of build up, multiple coats and little waste) which makes it easier and more pleasant, albeit more sanding. The only time I use spray can stuff is when I need small amounts of multiple colours and then I go over with a two part clear coat, to preserve the colours and give it some toughness. To economise, maybe use a hi-build epoxy primer (white)only! It will get chalky if left in the sun a lot, but will otherwise save you buying an extra gallon of urethane top coat, and will go on thick, fill sanding scratches etc, while still glossing about like a daggerboard gelcoat. You would want something tough so the boards will not get the vertical scratches fron the sand invariably in your trunk felt/gasket sides, which are aparently real performance killers.