Bottom’s Up

The primary purpose of bottom paint is to defend against plant growth, slime, barnacles, or similar crusty creatures hitching a free ride on your vessel’s bottom. Unprotected, your hull below the waterline makes a great surface for such creatures to adhere to. Once they do, they’ll be a drag both in terms of performance and aesthetics.

It would be great if all you had to do was slap a couple of coats of paint on the bottom and head off for your favorite cove. There are many variables to consider when choosing the right bottom paint for your boat. That means you are going to have to do some homework and ask questions, to ensure that the bottom paint you decide on will be compatible with the current coating over which it will be applied.

As a rule, avoid bargain brand paints and stick with the tried and true for this project.

Here are key points to keep in mind as you get underway. Check with your marina to make sure you’ll be allowed to paint your boat yourself on-site. Some boatyards and marinas prohibit this act as a simple point of business, others may not allow it due to environmental concerns or regulations.

Safety First

Understand that anti-fouling bottom paint and sanded fiberglass are toxic. Always wear a respirator and protective eyewear, gloves, and clothes when sanding, scraping, or painting. A tarp will be needed to capture the sanding residue and any paint chips. Make sure your vessel is firmly secured and perform a full hull check to ensure you won’t be painting over any damage that needs to be addressed. Safety is always rule number one.

Start With A Wash-down And Good Scrubbing

• Before applying any bottom paint, powerwash below the water line to ensure as clean a hull as possible. This is best done when the boat is first removed from the water as most organisms are easier to wash away before they’ve had a chance to dry and set.
• If you didn’t wash down immediately, it’s going to take a lot more elbow grease. Plenty of scrubbing and a random rotary sander will be your best friends. Be sure the hull is dry before starting this task.
• If the current bottom paint seems to be in good to fair shape, there’s no need to take it all off. Just scrape and sand any loose or flaky areas and recoat following the manufacturer’s directions on the can. If it’s in really bad shape, consider using a paint stripper formula or to have it professionally removed to completely clean the hull before starting over.

Pick The Right Paint

It’s important to choose the right type of paint for the job at hand. It can take research since so many formulas are available, but it will make a difference in the long run for your vessel.

• Anti-fouling paint is designed to guard against barnacles and zebra mussels
• Dual-purpose formulas guard against slime and algae
• Some paints will last one year while others multiple
• If you have an aluminum hull, avoid copper-based paints

There’s a lot to consider here – which is why so many boaters hire the pros.

Most potential problems can be prevented by simply asking an expert. Actually reading the directions on the label can be a game-changer. You’ll find tips on how thickly to apply the paint, the overcoating, and even launching times. If you’re going to do it yourself, just take your time and think it through. You’ll be heading out on the water before you know it.