best salt proofing coating for steel.

[lance on cloud nine]

Greetings Sailors - I hope you are all doing well and having some fun! I am making a few modifications on a galvanized trailer for my O'Day 23. I am extending the tongue a bit, and adding an extra cross member. I have always rinsed this trailer well after dunking it in salt water and it has held up pretty well. My question is - would anyone be able to recommend a good spray or brush on coating to help protect these new bare steel parts? Thanks a lot.