TotalBoat Underdog bottle ready for antifouling treatment to deter barnacles.
TotalBoat Underdog brush application on fiberglass hull for smooth coating.
TotalBoat Underdog roller application on wood hull for even coverage.
TotalBoat Underdog spray application on boat bottom for quick coat.
TotalBoat Underdog hull being coated to resist fouling during trailering and beaching.
TotalBoat Underdog durable finish ready for sea-ready protection.
TotalBoat Underdog 500 sq ft coverage guides hull coating planning.
TotalBoat Underdog black color option showing traditional antifouling finish.

TotalBoat

TotalBoat Underdog Marine Antifouling Bottom Paint – Black, Gallon (Fiberglass, Wood & Steel)

High-performance tools and home improvement made for confident daily results

$193.40

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Why customers choose TaskHolt Tools

Affordable, season-long antifouling protection

TotalBoat Underdog marine bottom paint offers a practical antifouling solution for boats with fiberglass, wood, bare steel, or iron bottoms. Its ablative action wears away as you move through the water, continuously exposing a fresh layer of biocide to help deter barnacles, mussels, and other marine growth from attaching. Because the coating wears down over the season, there is no buildup along the hull, which can simplify prep work before the next coat and reduce sanding time.

Smart features and what they mean for you

  • Single-season protection with copper biocide helps deter fouling in a range of saltwater conditions.
  • Durable finish stands up to trailering, beaching, and routine wear so you can keep boating with confidence.
  • Sticks to properly prepared fiberglass, wood, steel, and iron bottoms and is compatible with most previous bottom paints.

Underdog is easy to apply by brush, roller, or spray. It can be thinned up to 10% when needed to improve flow: brush/roller with TotalBoat Special Brushing Thinner 100, or spray with TotalBoat Spray Thinner 101. This makes it versatile for different project sizes and setups.

  • Coverage is about 500 square feet per gallon, making it a cost-conscious choice for typical hull sizes.
  • Available in gallon sizes with options in black, blue, and red for visibility and style considerations.

Designed for frequent-use boats, Underdog performs well in varied saltwater environments and is 100% made in the USA. It is intended for antifouling use below the waterline and should be applied to properly prepared substrates following the product guidelines. This coating is not for household use.

FAQ

Q: What boats can use TotalBoat Underdog Bottom Paint?

A: Suitable for fiberglass, wood, bare steel, and iron hulls, including sailboats, power boats, work boats, and fishing boats.

Q: How do you apply Underdog and can it be thinned?

A: Apply by brush, roller, or spray; thinning up to 10% with TotalBoat Special Brushing Thinner 100 for brush/roller or 101 for spray.

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