Is bottom paint necessary in fresh water?

[Omatako]

Whilst being a long way from an expert on the subject, I was once told that fresh water is far more likely to cause osmosis and gel coat blistering because the water is less dense and thus has an easier time migrating up follicles of glass fiber.

As far as personal experience with goes, I lived on an inland lake many years ago and took a boat from the coast that lived in a marina for several years with no blisters and in two years in fresh water it was like a golf ball.

This doesn't perhaps prove anything but it seems reason enough to put a decent coat of anti-foul on, hobbly gobblies aside.

Andre

[Fstbttms]

Originally Posted by Omatako

This doesn't perhaps prove anything but it seems reason enough to put a decent coat of anti-foul on, hobbly gobblies aside.

Unfortunately, since anti fouling paint does not block water from reaching the hull nor is it designed to, it plays little or no role in the mitgation of osmotic blistering.

[EliaSOS]

Many-most boaters in the Great Lakes put on bottom paint, I cannot see any reason. The 'slime' is insignificant its red gren algee. Fresh water boaties look at a boat hauled from the ocean, they grow gardens, that require hours-days of scraping. I know of a guy who had about 15 kg of Oysters when he haulled his ferro boat. Great lakes algee is nothing in comparison. An epoxy barrier coat IMHO and 2-part finish, is a far better barrier than bottom paint which in the past was had copper init to avoid animals growing and was designed to peel away. Lake superior where I spent most of my time is full of copper, Iron etc. Furtehr more if you are on the great lakes you mot likily pull your boat out every year May-October, put a good epoxy and powerwash it. Its a marketing ploy. (except maybe for race people)