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​Prepping A Boat For Bottom Paint


Painting tends to be a straight-forward process. But what if you’re about to paint something that’s destined for the water? The story changes. That’s certainly the case when prepping a boat for bottom paint! When preparing for this project, you need to consider various elements like wax, gel coat, and how well the paint will adhere to the hull. We’ve put together some of the most important steps to help make your prep work a breeze.

Key Points To Understand

Painting below the waterline is understandably a little different from the usual paint job. That’s why it’s important to know the key points before you proceed:

  • Anti-Fouling Paint is a phrase you’ll hear a lot. These are commercial “underwater” paints designed specifically to hold on to their color and adhesion in the marine environment. The name sounds a bit strange, but that’s all you need to know for now.
  • Steps will change depending on the gel coat. Your boat’s level of wax will determine the steps you need to take.
  • Safety. Boating Magazine recommends wearing a respirator, protective eyewear, gloves, and clothing you don’t mind getting dirty. Trust us—you might not think you need protective eyewear until you see how it feels to get a bit of sanded hull under an eyelid. Spare yourself the trip to the eye doctor and wear goggles—it’s much easier. And cheaper.

Now that you have the basics down, it’s time to start prepping your boat for bottom paint.

How To Prepare A Boat For Bottom Paint

Once you have your boat safely out of the water, elevated and dried, you’ve just arrived at the beginning. Here are the next steps on your checklist:

  • De-Waxing. Taking off the wax means accessing the hull directly, which is vital for the proper adhesion of primer and paint. Make sure you understand the gel coat quality on your boat and use the appropriate solvent or solution to remove the wax gently. You’ll need a lot of cloths/rags for this job, as you don’t want to rub over new spots with old globs of wax—this just re-waxes the surface.
  • Sanding. The hull will need some texture after this point, because this promotes adhesion for the primer and paint. Sand the boat down and use a “brushing thinner” to get rid of any leftover dust from the process.
  • Barrier Coating. Think about a “barrier coating” when prepping a boat for bottom paint. This helps prevent the absorption of water at this layer. This is the hull we’re talking about, after all—if your hull isn’t water-tight, nothing is.
  • Choose Your Coat. Many paints these days don’t require primer, and anti-fouling paint can be
     just as robust. Make sure you follow the recommendations of the individual anti-fouling paint, however. A simple read-through of one label can save you from an immeasurable amount of headaches down the road.

More Useful Boat Cleaning & Maintenance Products

Protecting and painting your boat’s hull will go a long helping you preserve its look for years to come. But if you want every part of your boat to hold on to as much life as possible, be sure to check out all of our boat cleaning and restoration products here at BoatLife!

Life Industries Corporation
4060 Bridge View Drive
N. Charleston, SC 29405
United States of America

toll free: (800) 382-9706
local: (843) 566-1225
fax: (843) 566-1275


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