Scott(702) sent an article that he found in a magazine that looks like a very good solution to the problem of boat trailer springs that rust so quickly. It was written by James Victory of Gautier, Mississippi.

Anyone who owns a boat trailer probably knows the frustration of having to replace rusty leaf springs. To put off this inevitability, I use a trick shown to me by a retired naval aviation mechanic. The method was used to protect aircraft landing gear from prolonged exposure to salt. Take a quart of regular motor oil and mix in a pint of STP oil additive. When thoroughly mixed, it has the consistency of honey. Then, with a firm paint brush, coat every inch of the leaf springs. The mixture is thin enough to work its way into the cracks and crevices, but thick enough to stick to the metal. When allowed to dry for 24 hours, the mixture firms up, and there is little or no loss when you hit the springs with a hose or submerge the trailer at the ramp. In fact, it is durable enough to provide an entire year's worth of protection.