How to Waterproof with Coat-It

How to Create a Tough, Waterproof Coating with Coat-It

Creating a durable, waterproof coating requires the right materials. Whether you're protecting the bottom of a boat, an animal trough, or a cinder block wall, selecting the proper coating can make all the difference. One excellent product for this purpose is Coat-It, a tough epoxy containing carbon for abrasion resistance and Kevlar for added toughness. Below, we’ll walk you through the steps to properly apply Coat-It for maximum durability and effectiveness.

Step 1: Surface Preparation

Before applying Coat-It, the surface must be properly prepared for optimal adhesion:

• Metal Surfaces (Steel, Aluminum, etc.)

  • Sand the surface or clean it using a Scotch-Brite pad.

  • Treat with marine phosphoric acid (e.g., Naval Jelly or Aluminum Brite) to remove oxidation.

  • Follow the manufacturer’s instructions for these products carefully.

• Wood Surfaces

  • Sand the surface and remove any loose paint or contaminants.

  • Remove all wood dust before application.

• Concrete, Cinder Block, or Brick

  • Ensure the surface is free from grease, oil, and loose paint, which can prevent proper bonding.

  • Clean the surface thoroughly before applying Coat-It.

Step 2: Repairing Surface Imperfections

• If the surface has gouges or holes, use Goop Marine Epoxy Paste for repairs.

• This two-part epoxy should be mixed in the provided cup.

• Since it is also an epoxy, it does not need to be fully cured before applying Coat-It—the two products will bond together seamlessly.

Step 3: Mixing Coat-It

Coat-It consists of two components: a resin and a hardener. Proper mixing is crucial to ensure effectiveness:

• The larger container holds the resin, leaving enough space to add the hardener for direct mixing.

• If mixing smaller quantities, use a 7:1 ratio (seven parts resin to one part hardener by weight).

• A postage scale can help measure accurate amounts.

• Once combined, mix thoroughly for 2-3 minutes, ensuring you scrape the sides and bottom of the container.

Step 4: Applying Coat-It

• Coat-It is highly viscous, making brushing difficult. Use the following methods for better application:

  • Disposable brush with shortened bristles

  • Squeegee (often the best option)

• Coat-It thickens before it fully hardens, allowing you to use any remaining material in the container for areas needing extra coverage.

Step 5: Curing and Additional Coats

• At 70°F, Coat-It cures in 10-12 hours.

• Lower temperatures increase cure time, while higher temperatures speed it up.

• A second coat can be applied after the first coat gels.

• Uncured Coat-It can be cleaned from tools using acetone or lacquer thinner.

Step 6: Dealing with Cold or Humid Conditions

• Cold and humid conditions can cause an oily residue to form on the surface.

• This can be easily washed off with soap and a scrub pad once cured.

Final Results: Waterproof Protection

Once fully cured, Coat-It forms a tough, waterproof barrier. A simple demonstration shows that a cardboard box coated with Coat-It remains dry even after 24 hours submerged in water.

Because of its waterproof characteristics, Coat-It can be used both above and below the waterline. It is available in:

• 2 lb kits (covers ~20 sq. ft.)

• 8 lb kits (covers ~80 sq. ft.)

For a durable, all-purpose waterproof epoxy sealer, Coat-It is available at TAP Plastics.