GLOBAL | Hunt Smart Surfaces GLOBAL | Hunt Smart SurfacesFrequently Asked Questions
A Historically, marine antifouling paints have used compounds toxic to marine organisms as a means of combating fouling. Foul-release coatings don't use copper or any other metal toxicant to provide effective biofouling control; rather their unique surface chemistry creates a surface to which fouling can not easily adhere. Because they employ a physical rather than a chemical means to reduce fouling, these silicone coatings have been ruled exempt from reporting under FIFRA (Public Law 95-396). NRL developed and patented an advanced foul- release coating system called the duplex silicone coating system to address the durability issues associated with silicone elastomeric coatings. This system employs a tough, cross-linked thermoplastic elastomeric layer (Silgan J501, Wacker Chemie, Ltd.) to bond the foul-release silicone topcoat to the anticorrosive system for ship hulls or to epoxy paint on concrete walls in power plants. The ESTCP demonstrations/validations included 6 Coast Guard aluminum hull boats, 2 Navy Range Boats, a Navy Transporter, an ONR/Lockheed prototype (SLICE) and power plant cooling water intakes (concrete walls, steel trash racks/traveling screens/deflecting veins). Barnacle adhesion measurements (ASTM D 5618-94). Barnacle adhesion measurements and water jet cleaning were developed as part of this project.
A Any business, organization or agency (public, private, government) whose physical assets are adversely affected by biofouling organisms and/or whose operating equipment performance and efficiency is adversely affected by biofouling organisms. Additionally, any business, organization or agency that might experience enhanced performance or operating efficiencies due to the superior hydrodynamic properties of silicone. Major markets of opportunity include:
A All vessels large and small will benefit from the Duplex Fouling Release Coating System. At this time, however, FHSM has not formulated the Duplex Fouling Release Coating System for hand application by untrained or D-I-Y applicators. Therefore, the smaller vessel owner should contact their FHSM representative for information and recommendations
A Duplex refers to the ability of the Tie Coat to create superior adhesion and durability between the system’s vastly different epoxy anti-corrosive layer and the silicone Surface Coat, effectively interlocking the two by employing a unique thermoplastic elastomeric formula. Additionally, the original Duplex name came from the use of two silicone Tie Coat and Surface Coat layers to achieve a superior overall system from the point of view of toughness, durability and foul release.
A The full system consists of four coats:
A Yes and no, as it depends on the circumstances of the particular project
A Yes, as long as all contaminants and loose paint are removed leaving a solid, intact surface that will accept epoxy paint.
A For ferrous and non-ferrous metals, SSPC-SP6 Commercial Blast Cleaning, or SSPC-SP12 Water-jetting to WJ-2. A bare substrate is a preferred with a profile depth of 3 mils. For concrete, SSPC-SP13 Surface Preparation of Concrete.
A FHSM’s silicone is similar to that used in the highest-grade outdoor caulking. That does not become brittle with age, heat or UV exposure, and is guaranteed by the manufacturer for 30 years. Excellent resistance to aging and the environment is one of the unique properties of silicones compared to other polymers. It is because silicones are based on silicon and oxygen polymer chains rather than carbon based polymer chains that these outstanding performance properties can be achieved.
A The other silicone fouling release systems have a similar surface coat silicone to the FHSM. However, that is where the similarities end. The differences are three fold:
A The FHSM system releases hard fouling on vessels at a range of: low speeds 10 knots - higher speeds of 42 knots as proven by the US Navy. Recent field trials have demonstrated success below and above proven ranges mentioned above.
For circulating and service water tunnels and other structures in power generation facilities, a season long (May to October) field trial in Lake Ontario demonstrated fouling release/self cleaning at flow rates as low as 0.5 ft/sec. in fresh water. In salt and brackish water with a constant flow rate as low as 7 ft/sec., biofouling organisms are unable to attach to intake surfaces and other related structures.
A Yes, because boat bottoms remain clean and free of bio-fouling and because of the slick and hydrophobic properties of the silicone Surface Coat, speeds increase and fuel consumption declines. In one recent sea trial, a ship’s speed increased 10+% compared to a copper ablative anti-fouling coating when operated at the same engine RPM’s and the fuel consumption dropped 10%. Results for other craft will vary depending on but not limited to such factors as hull design, weight, equipment maintenance, operating conditions and sea conditions.
For power plants, the early results of flow efficiency study when saltwater is pumped through penstocks suggests that an improvement in terms of energy savings can be as much as 18% in steel pipes coated with the Duplex System and as high as 55% in concrete pipes coated with the Duplex System. This study continues with the goal of defining savings as a monetary value per Mega Watt or Kilo Watt.
A The EPA does not require special certifications for the FHSM Duplex Fouling Release System (DFRS). Silicones in general are not seen as hazardous to the environment. The U.S. Navy received a Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) exemption during their field-testing. In fact, the surface coat is FDA compliant for contact with food. Furthermore, FHSM is not aware of any special regulations from California.
A Yes, the Tie Coat and Surface Coat products in the system are VOC compliant at 1.3 lb/gal or 156 g/L.
A Application can be by brush, roll or airless spray. Recommended airless spray equipment is GRACO King 56 to 1 Hydra-Spray or larger pump or equivalents of other manufacturers. Use 0.021 tip or larger for the Tie Coat and 0.021 tip or larger for the Surface Coat.
A In its cured state, moisture will not degrade or damage the silicone itself. However, silicone is more permeable to water vapor than other types of polymers. Thus a silicone coating by itself is not a good corrosion barrier. However, the underlying tie coat and epoxy layers are very good moisture and corrosion resistance barriers. Thus, the overall system is a good moisture and corrosion barrier.
The application of silicone is moisture sensitive, and it is harder to apply under damp conditions. Silicone should be applied when surface to be coated is at least 5 degrees above the dew point as with most epoxies. The humidity range is 30 to 85%. Mechanical means can be used to regulate humidity levels. The surface should be clean and dry to promote proper adhesion. Prior to application of the Duplex System, a FUJI Hunt Smart Surfaces representative should be notified if any conditions outside of these parameters exist.
A Minor scratches can be recoated with Surface Coat after cleaning surface with thinner to remove any surface contaminants.
Areas damaged down to bare substrate will require the bare steel only to be cleaned and two coats of epoxy (2nd epoxy with tethering agent) and Tie Coat to be applied to this area only (do not overlap existing Surface Coat), then Surface Coat application.
For other damage down to but not into the Tie Coat, then only Surface Coat re-application would be needed.
A By containment methods: tarps, screens, isolation, etc
A The shelf life is 1 year from date of manufacture in the container.
A Five (5) years as indicated in the FHSM warranties. Silicones are known to have long service life due to the properties discussed above, so lifetimes greater than 5 years are quite possible.
A Yes, both by phone for questions and for site evaluations, inspections and applications. A FSHM technical representative on site during application is required when a warranty is desired.
A Yes, two warranties are available. One warranty is offered for marine projects and the other for industrial/power projects. Both warranties are for a five (5) year period.
A The marine warranty includes a “fuel savings for commercial vessels” component stating that such vessels shall experience a 3% decrease in fuel consumed where the DFR system is applied. Refer to the warranty document for details of fuel monitoring procedures and historical records both prior to and during the warranty period