How to Seal a Marine Plywood Boat Deck | Step by Step Instructions

The following steps will show you how to seal a boat or yacht deck with SANI-TRED® marine plywood deck paint. Read on and learn how to waterproof wood for a boat.

Products Needed: PermaFlex®, LRB (Liquid Rubber Base), TAV (Thickening Activator), and Rubber Granules.

 

Step 1: Prepare the Substrate for Marine Plywood

The first step in sealing a boat floor is to prepare the marine plywood or other substrate thoroughly. This preparation is crucial for ensuring the effectiveness and longevity of the seal. Start by removing any loose or crumbly material from the surface. It is essential to ensure that the substrate is clean, dry, and free from any previously applied products or foreign matter.

For the best results, surfaces made of steel, aluminum, and fiberglass should be sandblasted. Sandblasting provides an ideal surface texture that promotes strong adhesion and enhances the durability of the seal. If sandblasting is not feasible, you can replicate this effect using coarse sandpaper. Sanding the surface creates a rough texture that helps the primer and sealant adhere more effectively, ensuring a lifetime of protection for your boat deck.

 

Step 2: Prime the Surface

Once the substrate is prepared, the next step is to prime any joints, seams, cracks, holes, and rough areas. Apply one coat of PermaFlex at a coverage rate of 240 square feet per gallon. This primer is crucial for ensuring that the anti-slip paint for boat decks adheres properly. PermaFlex penetrates deeply into the substrate, creating a strong bond that serves as a foundation for subsequent layers. Proper priming ensures that the coating system will be durable and long-lasting.

 

Step 3: Patch and Profile

After priming, it's time to patch and profile any joints, seams, cracks, holes, and rough areas using the LRB/TAV mixture (Liquid Rubber Base mixed with Thickening Activator). The mixture should be prepared by mixing 2 parts LRB with 1 part TAV to create a thick, caulk-like consistency.

For wall/floor junctions, apply a 1-inch diameter bead of the LRB/TAV mixture. Most cracks and seams require a 3/4-inch diameter bead. This mixture will molecularly weld to the PermaFlex primer, ensuring a seamless and durable repair. LRB can also be used by itself as a liquid membrane to smooth out and level any horizontal surface or as a coating for vertical and inverted surfaces. This versatility makes it an excellent choice for ensuring a smooth, uniform finish.

LRB/TAV “Round Calculator Bead Chart”

 

Step 4: Broadcast Rubber Granules

Next, apply a coat of PermaFlex at a coverage rate of 240 square feet per gallon. While the PermaFlex is still wet, broadcast the rubber texture granules onto the surface. This step is essential for creating an anti-slip texture that enhances safety and durability.

Our standard rubber granules are distributed at a rate of 0.175 pounds per square foot, while our smaller granules are distributed at 0.25 pounds per square foot. After the PermaFlex has cured, the texture granules will be bonded in place. Remove any excess granules by sweeping, blowing, or vacuuming to ensure a clean, even surface.

 

Step 5: Apply Liquid Rubber Base (LRB)

Once the texture granules are in place, apply a coat of LRB over the top. The amount of LRB you use will determine the final texture of the floor. If you prefer less texture, apply more LRB in one or multiple applications.

For standard size rubber granules (approximately 1/16 inch), apply the LRB at a rate of 60 square feet per gallon. For smaller rubber granules, apply the LRB at 80 square feet per gallon. Once the LRB has cured enough to walk on, you can proceed to the next step. This layer provides an additional waterproof barrier and ensures that the texture granules are securely encapsulated.

Step 6: Apply the Topcoat

The final step is to apply a topcoat of PermaFlex at a coverage rate of 240 square feet per gallon. This topcoat seals the entire surface, providing a durable, long-lasting finish that enhances the appearance and functionality of your boat deck. The topcoat ensures that the underlying layers are protected from wear and tear, UV rays, and harsh marine conditions.