Painting outdrives, stern gear, propellers and keels

Outdrives and stern gear are usually constructed from aluminum. Propellers are usually bronze or aluminum. Keels are typically cast iron or lead. It’s important to choose an antifouling that is hard, durable and suitable for these high wear areas and also one that is compatible with the substrate you are painting.

Step 1: Health and Safety

Before commencing preparatory work, ensure the area you are working in is adequately ventilated. Ensure you are wearing the correct PPE; we recommend safety glasses, goggles or visors, nitrile rubber gloves, overalls (ensuring skin is not exposed) and a solvent mask.

Step 2: Preparation

The key to protecting your underwater metals from corrosion is correct preparation of the substrate and choosing the best priming solution for your project. Before commencing any preparation, it is important to establish the type of metal you are working with.

Step 3: Priming

Apply a primer recommended for the selected antifouling and substrate; always follow the recommendations given on the product label.

Step 4: Applying antifouling

Apply the selected antifouling, following the label recommendations on film thickness, overcoating and immersions times carefully.

“Take care with zinc anodes!”

Care should be taken not to paint zinc anodes, which are often located next to the prop shafts, as this will seriously reduce their effectiveness. When painting your outdrives, underwater metals and keels, the longevity of any antifouling is difficult to predict as coating adhesion can be an issue, particularly on propellers. Thorough surface preparation is critical to promote good adhesion between the substrate and the coating.