Interlux ACT Ablative Antifouling Bottom Paint

Interlux ACT Ablative Antifouling Bottom Paint

Interlux ACT is a trusted single-season ablative bottom paint that delivers excellent season-to-season protection in moderate to heavy fouling waters. Using Ablative Copolymer Technology, the coating slowly wears away with use, continually exposing fresh biocide at the surface. This controlled erosion helps prevent marine growth while eliminating the heavy paint build-up and aggressive sanding associated with many hard bottom paints.

With a higher copper content and a built-in Slime Fighter additive, ACT is very effective at controlling shell fouling such as barnacles and zebra mussels, as well as weed, slime and algae. It can be used on fiberglass, wood and properly primed metal hulls (not aluminum) in fresh, salt and brackish water, making it a versatile choice for a wide range of powerboats and sailboats.

Available in popular colors including black, blue, red, green and brown, ACT is a go-to ablative paint for boaters and boatyards looking for reliable performance and easier maintenance between haul-outs.

Best Uses

• Single-season antifouling protection for powerboats and sailboats
• Boats kept in moderate to heavy fouling waters (algae, slime, barnacles, zebra mussels)
• Fresh, salt, and brackish water marinas and moorings
• Owners who want an ablative coating that minimizes paint build-up and sanding at recoat time
• Fiberglass, wood, and properly primed steel or lead hulls below the waterline (not suitable for aluminum)

Key Features & Benefits

• Ablative Copolymer Technology: Coating wears away in a controlled manner during use, continuously exposing fresh biocide and helping prevent premature wear-through.
• High copper content with Slime Fighter: Formulated to control hard growth such as barnacles and zebra mussels and soft growth like weed, slime and algae, keeping the hull cleaner for longer.
• Reduced paint build-up: Because the film gradually erodes, there is less old paint to sand off at recoat time compared to many hard bottom paints.
• Season-to-season protection: Provides dependable single-season protection when applied at the recommended film thickness and coverage.
• All-water versatility: Can be used in fresh, salt, and brackish waters, ideal for boats that move between different environments.
• Flexible application: Can be applied by brush, roller, or airless spray over most existing antifouling coatings that are in sound condition, following Interlux compatibility guidance.

Application & System Overview

Interlux ACT can be applied over most well-adhered antifouling paints or as part of an Interlux system over properly prepared bare substrates. Always read the product label and technical datasheet before starting your bottom paint project.

• Substrates: Fiberglass, wood, and properly primed steel or lead below the waterline (not for aluminum hulls or drives).
• Existing antifouling: Confirm compatibility using the Interlux antifouling compatibility chart. The existing coating must be aged, firmly adhered, and in good condition.
• Coats: Apply a minimum of two full coats, with an extra stripe coat on high-wear areas such as the waterline, chines, leading edges and rudders. Three coats are recommended on bare wood.
• Methods: Apply by brush, 3/8" nap solvent-resistant roller, or airless spray using equipment suitable for solvent-based marine coatings.

Stir or shake ACT thoroughly before and during application to keep the copper and resins evenly mixed. Thin only if necessary, and never more than the maximum amount specified on the label.

Surface Preparation Overview

Proper surface preparation is critical to adhesion and antifouling performance. The summary below should be used in conjunction with the full Interlux instructions.

Previously painted surfaces – good condition

• Scrub the bottom to remove slime, salts and loose growth, then rinse and allow to dry.
• Sand the existing coating with 80-grit wet-or-dry paper as recommended to create a smooth, dull surface.
• Remove all sanding residue and apply the recommended number of coats of ACT.

Previously painted surfaces – poor condition

• Completely remove loose, flaking, or excessively built-up antifouling paint.
• For fiberglass and wood, use an appropriate paint remover such as Interstrip 299E; for steel, sandblast to near white metal.
• Once the substrate is clean and sound, follow the appropriate bare fiberglass, bare wood, or primed metal system before applying ACT.

Bare fiberglass

• Remove mold-release agents and wax with the recommended Interlux fiberglass prep products.
• Fair any imperfections with a suitable marine fairing compound.
• Follow either the no-sand, sanding, or blister-prevention system recommended by Interlux, typically involving a primer or barrier coat such as InterProtect® 2000E before applying ACT.

Bare wood

• Sand the surface smooth with 80-grit paper and remove sanding dust.
• Apply the first coat of ACT thinned slightly with the recommended thinner to aid penetration, then apply additional full-strength coats as directed.
• Fill seams if needed with an appropriate seam compound before finishing with full coats of ACT.

Primed steel or lead

• Prime bare metal below the waterline according to Interlux recommendations.
• Within the primer’s overcoat window, apply the specified number of coats of ACT.

Application Tips

• Apply only when the product and surface temperatures are at or above the minimum temperature specified on the label (typically 50°F / 10°C and above).
• Use quality solvent-resistant rollers and brushes designed for marine coatings.
• Respect the stated drying and recoat times between coats and before launching the boat.
• Do not apply ACT over tin-based copolymer antifouling paints.
• After haul-out, clean the coated surface before relaunching to help reactivate the film and maintain performance.

Always consult the full Interlux ACT technical datasheet and product label for complete preparation, application, safety, and dry-time information before beginning your bottom painting project.

Frequently Asked Questions

Can I use Interlux ACT on aluminum hulls or outdrives?
No. Interlux ACT is not recommended for aluminum hulls, outdrives, or underwater aluminum components. It is designed for use on fiberglass, wood, and properly primed steel or lead below the waterline.

Is ACT suitable for freshwater and brackish water as well as saltwater?
Yes. ACT is formulated as a single-season ablative antifouling paint that can be used in fresh, salt, and brackish waters when applied at the recommended film thickness and coverage.

Can I apply ACT over my existing bottom paint?
In many cases, yes. ACT can be applied over most existing antifouling paints that are aged, tightly adhered, and in good condition. The bottom should be cleaned and prepared as directed, and you should always refer to the Interlux antifouling compatibility chart before overcoating.

How many coats of Interlux ACT do I need?
Most boats require at least two full coats of ACT for proper single-season protection, with an additional stripe coat on high-wear areas such as the waterline, chines, rudders, and leading edges. Bare wood and boats in heavy fouling areas may benefit from an extra coat.

How long before launch after applying ACT?
Dry and launch times depend on temperature and conditions, but under typical warm-weather conditions you can usually launch the boat the next day after the final coat. Always follow the specific dry-time guidance on the Interlux product label and technical datasheet for your conditions.

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