Barnacles on boats are not only unsightly, but they also cause resistance that decreases speed and increases fuel consumption. They can be stubborn critters, but there are some tried-and-true ways to remove them.
Read on for the best ways to remove barnacles from your boat’s bottom.
Manual Barnacle Removal
If barnacle buildup is extensive and covers large areas of your boat’s hull, you can use a pressure washer to remove the bulk of it. Be sure to spray the pressure washer parallel to the hull’s surface to avoid making gouges in the fiberglass.
Pressure washing is not very effective on young barnacles and runs a higher risk of damaging the gel coat.
For small patches of barnacles or those left after pressure washing, remove them with a scraper. It’s best to start with a wooden or plastic scraper to reduce the risk of damage. You may have to use a metal paint scraper for stubborn barnacles. Scrape parallel to the hull’s surface to get underneath the shells of the barnacles.
After the barnacles are removed, they may leave behind a calcium-based residue known as a husk, which needs to be chemically removed.
Chemical Barnacle Remover
Mild boat hull cleaners contain either a calcium remover (lime remover) or a weaker acid like oxalic, phosphoric, or citric acid to help remove barnacle residue. Apply a boat cleaner with a nylon brush and let it sit so the chemicals can take effect. Then wash and gently scrape off the residue. You may need to repeat this process several times to remove all husks.
If mild boat cleaners and acids are not effective after several attempts, you will need to use muriatic acid, which is a type of hydrochloric acid (HCl). Muriatic acid is highly corrosive and can damage your eyes, skin, and lungs, as well as paint, gel coat, metal, and plastics.
Handling muriatic acid requires gloves, protective clothing, and a respirator mask. It is recommended that only professionals use this acid as a hull cleaner.
How to Remove Barnacles From Boat in Water
If you need to remove barnacles while your boat is docked, manual removal is the best method. Use the gentlest scraper you can to remove the bulk of the barnacles. Use a metal paint scraper or putty knife only if necessary.
Pressure washing is a better choice for when your boat is on land and the barnacles have had time to dry out.
How to Get Barnacles Off Your Boat’s Motor
To get barnacles off your boat’s outboard motor, use a calcium remover or mildly acidic boat hull cleaner and a stiff-bristled brush. Let the cleaner sit before scrubbing. You’ll likely have to repeat this process a few times. Be sure to only use a mild cleaner to avoid damage to the paint, plastic, metal, or gel coat.
How to Remove Barnacles From Boat Lift
You should rinse your boat lift with fresh water after each use to avoid barnacle growth in the first place. But if there are already barnacles on your boat lift, follow the same steps to remove them as you did for the rest of your boat. If your boat lift is made of aluminum, be sure to use an aluminum-safe cleaner.