Why paint your boat?
It's amazing how a few coats of paint can transform a nondescript boat with a worn-out finish into one that garners "oohs and awes!" from fellow boaters at the dock. But beyond mere aesthetics, topside paints help to protect above-the-waterline areas (hull, deck and cabin) from damaging UV light, moisture and salt. There are three main classifications of topside paint: One-part polyurethanes, two-part polyurethanes and alkyd enamels. When selecting a topside paint, do-it-yourselfers should consider their skill level and balance that against the performance they seek.
What makes one-part polyurethane paints a good choice?
Best for novices and preferred by many pros, one-part polyurethanes are easier to apply than more complicated two-part formulations. One-part polyurethanes are ideal for do-it-yourselfers who can achieve near-professional results with a brush or roller. Even though one-part polyurethanes are not quite as hard or durable as two-part polyurethanes, many professional painters choose one-part polyurethanes over two-part formulations due to their ease of application.
What are the advantages and tradeoffs with two-part polyurethane paints?
Compared to one-part formulations, two-part polyurethanes offer superior color retention and greater durability. While some can be sprayed, brushed or rolled, others are for spray application only. Two-part polyurethanes require more surface preparation and priming than one-part polyurethanes—and they are generally more toxic, especially when sprayed. Some two-part polyurethanes will lift oil-based paints, so check for compatibility with the paint that is already on your boat. We tend not to recommend two-part formulations to inexperienced painters and feel that most two-part polyurethanes are best applied by the pros. So if you decide to go it alone, follow the instructions to the letter. You will find the instructions on the paint can’s label, or on a data sheet at the manufacturer’s website. Most of our online paint descriptions link to this information as well.
What kind of paint is a good choice for wood boats?
Traditional oil-based, alkyd paints are the easiest for an amateur to apply with a brush. Still very popular, they are more compatible with underlying surfaces, cost less and don’t require as much fuss as polyurethanes; however, gloss and color retention are lower. For traditional planked wood boats, alkyd enamels are a good choice for dealing with the expansion and contraction of wood. The oils in alkyd enamels are also chemically compatible with the natural oils in wood.
West Advisor articles are your enduring source for help.
West Advisor articles have been a trusted source for technical boating information since 1987. For help with topcoat application, see Do-it-Yourself Topside Painting. We also suggest you read Safety Gear for Boat Maintenance.