I am in the process of rebuilding my aluminum I-beam trailer, new hubs, springs, shackles, axle bolts, plates, bunks and bunk supports. It should be like new when I finish. When I removed the galvanized (now rusty) bunk supports, there was what appeared to be crusted on salt deposits between the supports and the square aluminum tubing. Upon cleaning this off with a wire brush, it appears that the aluminum has corroded (it s pitted). Is this normal, is it a reaction between the alum/galv? It is not close to going through the tube but, what should I do to these spots, and is this something I can inhibit when putting new supports on? Last question, this is a flats boat so the boat sits entirely on the bunks, not on keel rollers. Would it make a big difference if I moved the bunks out/in a few inches to avoid these “corroded” areas? Thanks for any/all input.
Yes, the crusty deposits are aluminum oxides that are due to galvanic corrosion from two dissimilar metals touching. The simplist solution to slow down this process is to clean and coat the areas in a good quality marine grease (like Mercury 2-4-C) before bolting everything up and tightening.
Keep the bunks in the same spot if you are happy with the way the boat sits.
Iain Pelto
Edgewater 185CC “Jumpin’ Bean II”