Tag Archives: antifouling

ablative bottom paint

How to Apply Water-based Antifouling to Wooden Boats

Antifouling paint can be applied to many different substrates including wooden boats. What is the recommended procedure for preparing the surface? Is a primer needed? What paint should I use? This article should answer all those questions. The Bottom Paint Store has 3 water-based antifouling products: Aquagard, Sea Hawk Monterey, and Interlux Fiberglass Bottomkote Aqua.

Aquagard Water-based Antifouling Bottom Paint

When applying antifouling paint to wooden boats, primer is optional. Antifouling paint can seep into the wood grain and create a strong bond. Usually, the first coat is thinned 10% to assist in penetrating the wood grain. Then the subsequent coats can be applied normally.

If adhesion is a major concern, then primer will promote adhesion. There are 2 Aquagard primers to choose from: 181 Solvent based primer and 190 Water based primer. They both accomplish the same task, but the water-based version has less VOC’s (volatile organic compounds). If you choose to use a solvent based primer and then a water based paint, make sure the primer is completely cured before proceeding. You can read the full application instructions on the Aquagard product page.

 Monterey Self Polishing Solvent Free Bottom Paint

When applying Sea Hawk Monterey to a wood hull, no primer is needed. You can use the same method of thinning the product to allow it to seep into the wood grain. If the wood can accept more paint after the first coat, you can repeat the process a second time. Here is the step by step process for Monterey:

Step 1 – CLEAN SURFACE

Surface must be clean, dry and free of contaminants.

Step 2 – SAND & CLEAN

Sand to a uniformly frosty, dull looking surface with 80-100 grit (no finer) sandpaper; remove any residue.

Step 3 – APPLY ANTIFOULANT

Apply two coats of Sea Hawk antifouling by brush, roller or spray. Apply first coat thinned 10% and let dry overnight. Apply two more coats of bottom paint allowing 3 to 6 hours between coats and a minimum overnight dry.

Interlux Fiberglass Bottomkote Aqua

BARE WOOD: It is essential to remove all contaminants from the surface prior to sanding and overcoating.

Sand with 80 grit paper.

Clean with Special Thinner 216. Repair any defects with Watertite Epoxy Filler.

Lightly sand and wipe clean. Surface must be free from all contamination.

Fill seams, if necessary, with Seam Compound Brown 30.

Apply first coat of Fiberglass Bottomkote® Aqua thinned with clean water (do not add more than 10% by volume).

Using a Signal Coat Indicator for Repainting Ablative Antifouling Paint

Antifouling paint is a type of underwater hull paint, also known as bottom paint. These specialized coatings are designed for the exterior of the hull of a ship or boat and combat the growth, as wells as, the detachment of underwater organisms, such as seaweed, algae, and barnacles. These aquatic life forms bind to the hull and impact a vessel’s performance and longevity.

Anti-fouling paints are often applied as one component of a multi-layering process which can have other benefits in addition to their antifouling properties, such as acting as a barrier against corrosion on metal hulls that will degrade and weaken the metal, or improving the flow of water past the hull of a boat or yacht.

Boaters recognized early on it is important to keep the bottom of their craft free of barnacles due to loss of speed and performance. The key is knowing when to pull your boat out of the water for a new bottom paint application. Ablative paints are typically reapplied every 1–3 years. One way to ensure you reapply your ablative antifouling paint when it’s needed is by adding a signal coat or flag coat.

To apply a signal/flag coat, when you are getting multiple coats of ablative bottom paint applied to your hull, make the first coat a different color. For example, if the bottom is going to be painted blue, make the first coat red. When the blue paint wears off and you see the red flag coat, it is time to repaint.

ablative bottom paint
Aquaguard is an excellent antifouling bottom paint

If you need further assistance with your boat painting project feel free to contact our technical team Monday-Friday 8:30-5:00 pm EST.

Antifouling Paint for Inflatable Boats

Be sure to apply a water-based ablative antifouling paint to your inflatable boat

Inflatable boats have become very popular due to their flexibility and variety of uses. If your inflatable-bottom dinghy stays in the water for long periods of time and you have decided to apply antifouling paint you have a few options. You’ll want to apply a water-based ablative antifouling such as Monterey by Sea Hawk, one quart is enough for two coats on an 8-10′ boat. Avoid copper-based paint on aluminum. Before application clean the area with a maroon Scotchbrite pad for good adhesion. These paints tend to be flexible and adhere well to PVC and Hypalon but since they are ablative they can easily rub off so be careful when storing your dinghy on deck or deflating it for longer storage to protect surrounding areas from paint.

Monterey Bottom Paint

If you need further assistance with your inflatable boat paint project do not hesitate to contact our technical team Monday-Friday 8:30-5:00 pm EST.