Barrier Paints for Boats
At Fisheries Supply , we stock barrier paints used by recreational boaters and commercial fishing boats.
What to Know
- Barrier paints protect hulls from moisture, osmosis, and corrosion.
- They differ from antifouling paints in purpose and formulation.
- Epoxy and polyurethane systems suit different hull materials.
- Surface preparation and curing time directly affect performance.
What Are Barrier Paints and Why Use Them?
Barrier paints are specialized marine coatings designed to protect a boat’s hull from water intrusion, osmosis, and corrosion. Applied below the waterline, they create a durable, waterproof layer that helps preserve hull structure and performance over time.
Barrier paints act as a moisture-blocking shield between the hull and the surrounding water. Unlike antifouling paints, which are designed to reduce marine growth, barrier coats focus on preventing water absorption into fiberglass, wood, or metal substrates.
- Waterproof protection: Forms a continuous barrier against water intrusion.
- Osmosis prevention: Helps reduce blistering and long-term hull degradation.
- Corrosion resistance: Useful for metal and composite hulls in saltwater.
Types of Barrier Paints and Typical Applications
Different hull materials and operating conditions call for different barrier paint formulations. Fisheries Supply carries barrier coats suited to common recreational and commercial hull types.
- Epoxy-based barrier paints: Known for strong adhesion and durability on fiberglass hulls.
- Polyurethane barrier paints: Offer added flexibility and UV resistance for wood or composite hulls.
- Two-part formulations: Provide increased chemical resistance and long-term protection.
Applying Barrier Paint
Correct application is essential for barrier paints to perform as intended. Surface preparation, film thickness, and curing time all affect the coating’s effectiveness.
- Surface preparation: Clean and sand the hull thoroughly to promote adhesion.
- Priming: Apply a compatible primer when specified by the manufacturer.
- Application: Apply evenly using a brush, roller, or spray equipment as directed.
- Curing: Allow proper drying and curing before launching or applying antifouling paint.
Maintenance and Paint Compatibility
Barrier coats form a critical protective layer, but periodic inspection helps ensure continued performance. Touch-ups may be required if the coating is damaged or worn.
Fisheries Supply also offers compatible primers, sealers, and antifouling paints intended to work with common barrier systems, allowing for a coordinated below-the-waterline coating approach.
Frequently Asked Questions
How many coats of barrier paint are typically applied, and at what thickness?
Typically, two coats of epoxy barrier paint, each applied at 8–12 mils wet film thickness, are recommended for full protection. Applying a single thick coat may affect curing and adhesion.
Can antifouling bottom paint be applied over a barrier coat right away?
Yes. Applying antifouling paint while the barrier coat is still tacky allows for chemical bonding and improved adhesion. If that window is missed, light sanding is required.
Which barrier paint brands are available from Fisheries Supply?
Fisheries Supply carries barrier coating products such as Pettit Protect Epoxy Barrier Coat, Interlux InterProtect 2000E, and Marshall’s Cove Marine Paint, formulated for fiberglass, aluminum, and steel hulls.
What is the primary purpose of applying a barrier paint to a boat hull?
Barrier paints are specialized marine coatings designed to protect a hull from water penetration, osmosis, and corrosion. Unlike antifouling paints which focus on marine growth, barrier coats create a waterproof seal that prevents moisture from reaching the fiberglass or wood, effectively stopping the development of osmotic blisters.
Which types of hulls are compatible with epoxy-based barrier paints?
Epoxy-based barrier paints are highly versatile and known for superior adhesion. They are the preferred choice for fiberglass hulls to prevent blistering, but they are also excellent for use on underwater metals such as aluminum, steel, lead, and cast iron to provide corrosion resistance.
What happens if I sand through the barrier coat while removing old bottom paint?
Sanding through the barrier coat compromises the waterproof seal and can lead to expensive repairs if water begins to migrate into the hull laminate. When removing old antifouling layers, it is important to move slowly and remove only enough surface material to create a texture for the new paint without damaging the underlying protective epoxy layer.