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Marine Services: Bottom Painting/Out-Drive Painting
There are three key reasons why antifouling growth should be prevented:
SAFETY: Heavy fouling growth reduces the responsiveness of the craft and makes it sit lower in the water. This can have serious implications in challenging weather conditions.
PROTECTION: Prolonged fouling growth will damage the substrate of the hull. For example, the natural glues marine organisms use to attach to the hull damage wood and fiberglass.
SPEED & EFFICIENCY: Fouling causes drag, which slows you down and increases fuel
One of the most common questions that people ask is 'How much bottom paint will I need for my boat?' This is a difficult question to answer because much depends upon how heavily the painter applies the bottom paint. We can generalize and assume that we are covering the surface as thickly as possible without runs. For recommendations pertaining to the application of two coats of bottom paint, please read our Paint Amount Tips.
How Antifouling Paints Work
ABLATIVE ANTIFOULING – Ablative Antifouling wear away with use, which reduces paint buildup. This reduces the maintenance and preparation needed when it’s time to apply more antifouling paint and ends the annual ritual of sanding. Ablative Antifouling, s not only provide excellent antifouling properties but also can be applied over most other antifouling paints.
HARD ANTIFOULING – The technical term for these
types of antifouling paints is ‘contact leaching’. The paint
dries to a porous film that is parted with biocides, which leach out on
contact with water to prevent fouling growth. This leaching is chemically
designed to release biocide throughout the season, but the amount will
steadily decrease until there is not enough biocide coming out of the
paint film to maintain fouling protection. Once the biocide is exhausted,
the hard paint film remains on the boat. Hard antifouling do not retain
their antifouling ability out of the water and cannot be hauled and relaunched
without repainting. One of the main benefits of this type of antifouling
is its resistance to abrasion and rubbing. This makes it ideal for fast
powerboats, racing sailboats or boats where the owners have the bottoms
scrubbed regularly. Most hard antifouling paints can be wet sanded and
burnished prior to launch to reduce drag and improve hull speed.
Common sense about Bottom Painting
The main purpose of bottom painting is to prevent the growth of barnacles and other fouling agents on the bottom of the boat. The best way to do this is to apply a copper based bottom paint. Copper is the active anti-fouling agent. The more copper you apply the better it will work. Judge bottom paints by:
A. The amount of copper each contains
B. Whether the paint is a "Hard" or a "Soft" based paint
For the Chesapeake Bay area, one coat per summer of a paint with about 50% Cuprous Oxide in a soft base will do a good job. This has proven itself year after year in this area. An alternative for those heading South to Florida waters is Petit Trinidad. For longer periods between haul outs add additional coats of paint. A second coat will add an additional season although some fouling may be expected towards the end of the second year if the boat is used a lot. Soft bottom paints such as Neptune, Micron, Trinidad work best when the boat is used periodically to allow some of the paint to slough off. We will apply whichever paint you select and help you to determine your needs depending on your sailing plans.
Bottom Painting Tips
Whether you have a 19' cuddy or a 38' cruiser, it seems like it's a 700' cruise ship when it comes time to paint the bottom. If you're bottom painting for the first time, there are a couple things to decide, whether you're doing it yourself or having it done by us. Would you rather spend less money now and more time or money on labor in the future, or invest a little more money now and save on labor later on? This will help determine the type of product you put on your boat, and how often you'll have to reapply it to keep doing what it should.
Keep in mind, bottom paint isn't just there for looks, it has a purpose. Some products are designed to "slough" off of the boat. Others have a property that leaches out of the paint but leaves the color. Just because you see the paint, that doesn't mean you don't need to paint again. There are single season paints, multi-season paints, hard paints, standard antifouling and Teflon-based paints, etc. There are also several types of primers or under coating's from which to choose.
If this isn't the first time the bottom is being painted, it's important to know what's on your boat now. Keep in mind that some products can be covered over, and some need to be sanded or stripped to start fresh with a different product. Switching brands, if the paint TYPE is the same, won't cause a problem. But even if you're staying with the same brand, a different TYPE of paint could mean stripping the existing product back to the fiberglass. We have manufacturer's product guides to help you determine what you'll need to do.
Make sure the hull is in good condition. Check for cracks or blistering in fiberglass, and seal seams on wood boats. Good prep work is 90% of any job, especially when it comes to bottom work. Do any necessary repairs, or have them done. Ignoring problems will only create worse damage and more expensive repairs later. If you're starting with a bare surface, sand the surface or use a "sandless primer" first to ensure good adhesion. Otherwise, the bottom will flake or peel. If you're working with a a previously painted surface, scuff the existing paint for good adhesion of the new paint. Pay particular attention to any areas where there is flaking or peeling. This is a sign of poor prep the first time, and will cause problems with the new paint if not prepped well this time around.
Using an under coater is a good idea, whether you're painting new or older fiberglass. It will protect your new boat from water absorption, as well as seal your older boat's fiberglass. Even new fiberglass will allow absorption of water, so the best time to start using an under coater for maximum protection is when the fiberglass is new.
The proper thickness is also a factor, both under coater and bottom paint, if your boat is to be protected properly. Multiple thin coats of paint are better than one thick coat. Skimping on the number of coats, or adding too much thinner to "stretch" the paint won't save you money. Follow manufacturers' instructions for application, and the product will do what it's supposed to, for as long as it's supposed to. Otherwise, you'll just be doing the job again sooner and spending more time and money than you saved by shortcutting, or your boat won't be getting the protection it should.
When choosing a bottom paint system, consider price and labor, then decide whether you prefer a more expensive product that saves labor and works better or longer, or a less expensive product that will not last as long or protect your boat as well.
To help determine when it's time to repaint, use a different color for your first coat of paint. Then do the color you want. When the color under it starts to show through, you'll know you're down to the last coat and it's time to repaint