i have this white guey stuff around where the railings meet the floor and its eating the aluminum . i disconnect the batteries every time.
after a while it gets hard like crystals. is it a battery problem? the last pontoon boat i had it never happened.
You say "guey" stuff. To us, that means soft and squishy. If its white and crystalline/ powdery stuff than the rails are reacting with another metal. What are the rails made of , stainless or aluminum? And what type of fasteners are used to screw them down? Are they welded down?
Have you reached out to the builder?
More info needed to provide a helpful answer.