We are having the same problem but ours is also on the trailer frame as well and it has only been a year and 2 months. During that time we have only put our boat in the water a handful of times in that year definitely not enough time to be causing rust and that’s even after we washed our trailer...
We purchased a “galvanized“ Wolverine (Hot Summer Industries) pontoon boat trailer 1 year and 2 months ago and The frame is already starting to rust. I have sent several emails to the companies president Lyle Johnson and he avoided my statements I made I guess you could say about the trailer...
