9.9 hp nissan outboard-paint pealing off

I have an older 9.9 hp Nissan outboard that is sitting in my garage. The blue paint is pealing off it everywhere. The uncovered aluminum looks like it has white powder on it. Like a corroded battery terminal. I hosed it of with fresh water and it continues to corrode and peal. Any ideas of what is going on??? Any ideas as how to stop it? I read about "aluminum etch" that may cure the corrossion problem,but I don't know where to buy it. I want to repaint the outboard,but need to stop the corrosion first or the paint will probably just bubble up and peal off again.

Ideas????

Thanks!

You might consider West System 860 aluminum etch. See http://www.westsystem.com/ss/a-nose-for-speed/