Re: Trailer Rust Removal
Take the boat off the trailer, remove all lights, remove all plastic, etc. and tow it to a sand blasting company. Have them blast it, get it back, clean it up with acetone or something similar. Park it in the driveway or whatever on a warm sunny day, get a cheap HVLP gun and an air compressor and spray away. Or you could roll the paint on with a foam roller. Your choice.
For spot fixes, cleaning the rust off is straight-forward - use sandpaper, sandblaster, wire brush, wire wheel, etc until it's gone, paint over it. Problem is it'll come right back!
The long-term solution is a galvanized trailer. These 20+ year old painted steel jobs are all internally rusty by now, making rust killing just about impossible.