Comprehensive Boat Trailer Maintenance and Corrosion Protection (Jan 2026)

Thoroughly rinse the entire trailer with fresh water to remove loose sand and salt. Perform a visual inspection of the frame, looking for 'white rust' (zinc oxide) or 'red rust' (iron oxide). Focus specifically on the 'V' cross-members and the inner channels of the C-section or box frame where salt often hides.

If the boat is on the trailer, ensure all tie-down straps are tight and the winch post is secure. Ideally, perform major maintenance with the boat off the trailer, but if not possible, ensure the work area is level and the trailer is hitched to a vehicle or securely blocked to prevent movement.

Mix your salt neutraliser in a dedicated applicator or foam cannon. For Australian summer conditions, ensure the trailer surface is cool to the touch before applying chemicals. If the metal is over 40°C, the chemicals will evaporate before they can effectively dissolve the salt crystals.

Wear eye protection and gloves. Marine degreasers and salt removers are often alkaline and can cause skin irritation. Ensure you are working on a surface where runoff can be managed, ideally a grassed area or a wash-bay with a silt trap, as coastal red dust and salt can clog residential drains.

Apply the salt-neutralising solution to the entire trailer, starting from the front hitch and moving backward. Pay special attention to the leaf springs, brake calipers, and the inside of the wheel rims. Let the solution dwell for 5-10 minutes, but do not allow it to dry. The chemical reaction breaks the ionic bond between the salt and the metal.

Rinse the trailer thoroughly using a high-pressure cleaner. Direct the spray into every nook, including drain holes in the box sections. In Australia, red dust often mixes with salt to create a corrosive paste; ensure all visible mud and dust are removed from the undercarriage and axle assembly.

Jack up one side of the trailer and support it with jack stands. Spin the wheel and listen for any rumbling or grinding noises. Wiggle the wheel vertically; any significant play indicates the bearings need tightening or replacement. Remove the dust cap to inspect the grease color. If it's milky, water has entered and a full repack is required.

Using a grease gun loaded with high-quality marine grease, pump grease into the nipple on the bearing protector. Continue until the spring-loaded piston moves outward. Do not overfill to the point where the seal at the back of the hub bursts. This internal pressure prevents water from being sucked in when the hot hub hits cold water.

For trailers with brakes, spray the callipers and discs with a dedicated brake cleaner. If you have drum brakes, they must be flushed with fresh water via the wash-out port. Inspect the brake lines for any signs of swelling or corrosion, particularly at the junctions near the axle.

Leaf springs are the most common failure point. Use a wire brush to remove loose flakey rust. Once clean, apply a liberal coating of lanolin spray. Lanolin is 'self-healing' and won't wash off as easily as petroleum-based sprays. It penetrates between the leaves to prevent friction and internal corrosion.

Inspect the trailer plug for green corrosion (verdigris). Clean the pins with a small wire brush or contact cleaner. Apply a dielectric grease to the terminals to prevent moisture ingress. Check all lights, ensuring the seals on the LED units are intact, as the Australian sun can crack cheap plastic housings over time.

Extend the jockey wheel fully and apply a light coat of grease to the inner tube. Lubricate the winch gears and the handle pivot point. Inspect the winch strap or cable for fraying; UV damage in Australia can weaken polyester straps significantly over 2-3 seasons.

Adjust tyre pressures to the manufacturer's specification (usually 45-60 PSI for light truck trailer tyres). Inspect the sidewalls for 'dry rot' or cracking caused by UV exposure. In the heat of January, under-inflated tyres are prone to blowouts due to excessive sidewall flex and heat buildup.

Identify any areas where the dull grey galvanising has been scratched back to bare steel. Clean these areas with a degreaser, lightly sand, and apply two coats of 99% zinc-rich 'cold galv' spray. This provides sacrificial protection to the underlying steel.

Check that all rollers turn freely. If they are seized, the friction can damage the boat's hull. Apply a silicone-based lubricant to the roller spindles. Inspect skids for worn carpet or cracked plastic that could expose mounting bolts to the hull.

Apply a final 'fogging' coat of lanolin or a dedicated marine wax to the entire exterior of the frame. This creates a hydrophobic barrier that makes the next wash-down significantly easier and provides a UV shield for any plastic or rubber components.