Antifouling Questions

Why Has My Antifouling Paint Turned Green At The Waterline Since Immersion?

Antifouling paints are not meant to be cosmetic or decorative coatings and while every effort is made to make them as aesthetically pleasing as possible. The copper compound within the antifouling is difficult to mask with color pigments.
All antifouling paints change when they are immersed. So don't be surprised when you have finished and the color is not what you had hoped from the color chart, The true color will establish itself after the boat has been launched. Copolymer and ablative type coatings tend to fade more than hard antifouling paints.
Along the waterline you will often the antifouling looks dirty or faded, and can even turn green. This is due to the reaction of the paint with oxygen forming green copper oxide. Also paints with a higher copper content will turn greener at the waterline than paints with a lower copper content. For these reasons you should try keep the paint as close to the true waterline as possible. Fading is more noticeable in of ablative coatings than in hard coatings.

HOW OFTEN SHOULD I PAINT MY BOTTOM?

That depends on the type of antifouling that is used. The longevity of multi-season copolymers such as Micron Extra & Micron CSC is related to the amount of paint applied. These paints will retain the antifouling properties as long as the paint is on the hull. Hard antifouling paints work by leaching biocide out of the paint film and leaving the paint film behind. When this paint film is left out of the water it oxidizes and any biocide that is left in the coating will not leach out at the proper rate to control fouling.


MUST I SAND THE BOTTOM BEFORE REPAINTING WITH THE SAME ANTIFOULING ESPECIALLY SINCE IT WAS POWERWASHED IN THE FALL?


Antifouling paint is not meant to be exposed to the elements and when it sits out of the water for a couple of months the outside layer of paint film becomes oxidized, and gets soft, plus it picks up dirt and dust. New paint does not adhere well to this type of surface and may begin to peel off. Most non-copolymer paints have a porous "leach layer" and if they are painted over, after just a power washing the pigment and the resin penetrate into that porosity and leave a "blush" of cuprous oxide on the surface. This is a cosmetic problem and does not really affect the antifouling quality of the paint but most people if they buy blue paint they want it to look blue not purple. High-pressure fresh water washing (3000 psi) will remove the leach layer but the paint will need to be overcoated immediately after it dries. The other reason for sanding antifouling paint is that there is only so much paint that will hold onto a given surface. That amount may be 10 coats or the first coat may delaminate. This is the related to how good the original surface preparation was and how it is maintained between recoating. Sanding when recoating will add to the longevity of the bottom jobs. By sanding the bottom in the spring you will get more coats to adhere and forestall the day when you must remove all the antifouling paint from the surface. Soft rosin based antifoulings must always be sanded even if they have just been powerwashed.

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What Is The Difference Between Hard & Soft Antifouling Paints?

Antifouling type is dictated by the quality, combination, quantity and type of resin.

Copolymer and Ablative Antifoulings
These types of antifoulings are partially soluble which means that as water passes across the surface of the coating, the coating wears down much like a bar of soap would wear away The action of the water steadily reduces the thickness of the paint at a controlled rate, which results in always having fresh biocide at the surface of the paint throughout the season. For this reason these types of antifoulings have the capability to perform in the areas of highest fouling challenge.

Hard antifoulings leach the biocide out of the paint film and leave the paint film behind on the hull, which causes a build up of old, spent coatings, Because copolymer and ablative types of antifoulings wear away with use. There is no build-up of coatings that will eventually have to be removed from the surface. The minimal build up reduces the maintenance and preparation needed when it is time to apply more anti-fouling. In addition Copolymer types such as Micron Extra with Biolux and Micron CSC can be hauled and relaunched without repainting as the longevity these coatings are related to the thickness of the paint.

Ablative types such as Fiberglass Bottomkote Act do not retain their antifouling ability for more than 30 days after being hauled out.

Hard Antifoulings
The technical term for these types of antifouling paints is "contact leaching". The paint dries to a porous film that is packed with Biocides, which leach out on contact with water to prevent fouling growth. This leaching is chemically design 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. 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 cleaned regularly.

Most hard antifouling paints can be wet sanded and burnished prior launch to reduce drag and improve hull speed.

A disadvantage to hard antifouling paint is the buildup of residual paint film that occurs when the surface is not properly sanded prior to application of new coats of antifouling. When hard paints are hauled and stored for the winter season, the paint film, as well as the biocide oxidizes and this makes it more difficult to release more biocide out of the film. For this reason, they must be sanded and recoated with fresh antifoulinq before relaunching.

Teflon Antifoulings
Most people associate Teflon with nonstick household products or with the space program, but the properties that made it perfect for those applications also make it an ideal ingredient in antifouling paint. Teflon creates the lowest coefficient of drag in any coating available. The lower the friction, the less energy is required to move the boat through the water. For powerboats this means greater RPM's, increasing speed and fuel savings. For sailboats, greater speeds are achieved with less wind.

Soft Antifoulings
Soft or sloughing antifoulings provides dependable low cost protection for cruising boats or boats with displacement or non-planing hulls. These paints are easy to clean and remove at haul out which prevents paint build-up. These types of coatings must be launched within 48 hours of painting to retain maximum effect effectiveness.

Water Based Antifoulings

Hard Acrylic Waterbased Antifouling Paint provides a hard, scrubbable finish that will give protection from all forms of fouling. Fiberglass Bottomkote Aqua is perfect for use on either cruising or performance boats, and for those who want a little extra speed, the surface can be wet-sanded to provide a smooth racing finish with less drag.
Fiberglass Bottomkote Aqua is also low in Volatile Organic Content (VOC) which limits solvent emission into our atmosphere, with the added benefit of easy clean up with soap and water.

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Is A Higher Copper Content Equal Better Antifouling Performance?

The level of copper is not the only determining factor of how an antifouling paint will perform.
The resin-binder system, the material that holds the paint together, is equally important. Not only does the resin-binder system hold the paint together, it is the mechanism that determines how fast the copper and other biocide will be released. The resin-binder system must be carefully tailored for the amount and type of copper and other biocides used to obtain maximum efficiency The amount of copper or other biocide may effect the life of an antifouling paint but the sophistication of the resin-binder system to hold and release copper or other biocide at the proper rate is far more important to the effectiveness of the antifouling. A copolymer or ablative antifouling will release biocide at nearly constant rate throughout its life. For this reason, highly efficient antifouling paints like Micron, are less dependent on large amounts of copper and other Biocides and deliver the best possible performance.

The presence of boosting biocides, such as Biolux, by keeping the bottom clear of slime will make the copper more effective.
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(Note) We Here At Gig Harbor Marina Try And Use Paints With A Lower Copper Content On Boats With Outdrives. We Have Observed A Higher Rate Of Electrolysis On Outdrives In Contact With A Paint With A High Copper Content. You Should Always Have A Small Unpainted Strip Between Outdrives And Bottom Paint.

Why Should I Have To Paint My Vessel's Bottom?

Once fouling has established a hold on a boat hull it will rapidly spread or "colonize" the surface. Prevention is therefore better than the cure of having to remove the fouling by scraping.

There are a number of key reasons to keep your hull free from fouling:

Safety - Heavy fouling growth reduces responsiveness of the craft. The added weight of the fouling can make the boat sit lower in the water than intended. This can have obvious implications in heavy weather conditions.

Protection - Prolonged growth of certain types of fouling can damage the substrate of the hull. For example, the natural glues used to attach organisms to the hull can damage wood and fiberglass. Fouling can also clog water intakes and cause damage to the engines.

Speed and efficiency - Fouling causes drag. As drag is increased, fuel consumption increases and speed is reduced even to the point where a planing hull may not be able to get on plane. For racing boats, this can be the difference between winning and losing a race.
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What's This I Hear About Pettit's Irgarol & Interlux's Biolux Anti Slime Additives?

Trinidad SR Slime-Resistant Antifouling Paint

How do you make the best better? By adding new technological developments to your number one antifouling paint. Trinidad SR has the same basic hard-to-improve-on formula as our regular Trinidad but with the addition of a booster additive called Irgarol, that significantly reduces soft growth and slime (SR stands for Slime Resistant). Irgarol was developed by the Ciba Additive Group has gone through years of extensive testing under the auspices of the EPA. Trinidad SR meets all VOC (Volatile Organic Compounds) regulations. Trinidad SR high copper load (contains 70.0% cuprous oxide), will give excellent service even in most heavily infested waters. Trinidad SR is easy to apply by brush, roller or spray and has excellent adhesion to fiberglass, wood and steel hulls.
Trinidad SR is available in four colors.
Courtesy Of www.petitprod.com



What is Biolux
Biolux is a unique antifouling technology developed by Interlux incorporating organic boosting biocides into a special biocide release system. This blocks slime growth for a fouling free boat bottom.

How does it work?
Just like ordinary plants, Slime and Algae feed on sunlight. Formulations that use Biolux technology prevent algae and slime from being able to grow by acting like sunscreen to block this process.

Soon after the boat is launched it comes in contact with algae in the water. Once these materials attach and feed, they begin to secrete a gel like substance that attracts more algae until it begins to look like a carpet on the bottom of your boat. This increases drag, increases fuel consumption and makes the boat more difficult to handle, which can be a problem in heavy weather. If left on the surface, it restricts the copper being released to the surface to prevent shell fouling.
Courtesy Of www.yachtpaint.com