No. 4 – A Painted tubular steel frame on a salt water boat trailer is a mistake
Boat trailers made of tubular steel or aluminum are fairly popular, especially on mid- to lower-priced boats. But tubular metal frames have two fundamental problems in salt water:
- You can’t see inside the frame to inspect for rust or other problems
- You can’t easily rinse the inside of the frame tubes
If the frame is galvanized steel or aluminum, this may not be a problem. However, painted tubular steel is a different story. Trailers built with painted tubular steel are popular on freshwater boats, and their owners may be tempted to venture out into bays or near-coastal waters for the occasional salt water trip.
Toy Boat 1, which was an aluminum bass boat, had such a trailer. We made the mistake of taking it into the waters of San Diego Bay early on. We took the boat to a local lake the next day, thinking that dunking the trailer in fresh water would be enough to rinse it out.
Not a chance. Within a year, we discovered that a number of welds were nearly rusted thru from the inside. Things were so bad that the trailer actually came apart when raised on a lift at a welding shop.
Open (“C”) channel or I-Beam galvanized steel or aluminum are the time-tested choices for salt water boat trailers. This type of construction allows welds and joints to be instantly inspected. In fact, with this kind of construction, even a painted frame can be used successfully in salt water.
Our very first salt water skiff was carried on a painted open-channel steel trailer. Painted flat black, we used it for quite a while, entirely in salt water. The trick was to inspect the trailer after every launch. At the first sign of corrosion, we cleaned off the rust with a wire brush, then primed and repainted it on-the-spot. The flat black was an easy color match.