MERCER02-14
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and 30% humidity. The maximum ambient air and substrate surface temperature for application
are 32°C and 38°C, respectively.
Small scratches to the topcoat damage can be repaired by cleaning the area and recoating.
However, damage to the underlying coat or bare substrate requires a new application (Wells and
Sytsma 2009).
D.
Exsil 2200
Exsil 2200 is a silicone elastomer without exuding silicone oil. When applied over a Plastocor
primer to a 3000 ft
2
concrete intake bay, the areawas heavily fouled after 2½ years. Therewere
also several areas of Exsil that had peeled away from thePlastocor primer (Gross 1997).
E.
Adsil, CatalyzedSiloxaneCoating
Catalyzed siloxane coatings are produced by Adsil. They are inorganic film formers that adhere
by both London force and covalent bond methods to bare non-ferrous metals and concrete. A
fully cured film exhibits a slight positive charge, which is hydrophobic and oliophobic, providing
a natural repellant against debris. The siloxane film characteristics make it resistant to staining
and grime. Microguard AD35, a variety of this coating type, was tested on a push boat. It was
applied after the boat had been cleaned and rinsedwith PLC-1 andAD72-930, both produced by
Adsil. After 2 ½ months, no permanent marine growth was present. These products have not
been testedon intake pipes (Ledonne, personal communication, 2014).
5.2.1.2.
Fluoropolymer
Fluoropolymers are thermoset polymers based on compounds made from carbon bonded to
fluorine. This type of coating is thinner and harder than silicone withmore mechanical strength
(Wells and Sytsma 2009). The application thickness of fluoropolymer coatings is 75 µm
(Chambers et al. 2006). These coatings have a well-organized surface of tightly packed
fluorinated groups that lowers the surface energy. They also have a highmodulus, which requires
greater force for interfacial fracture, which occurs by shear (Brady 2005).
Examples:
A.
InternationalMarineCoating andNipponPaint, Intersleek 970
Intersleek 970 is used in the Intersleek 900 foul-release systemmanufactured by International
Marine Coating and Nippon Paint. The Intersleek 900 system includes an anticorrosive primer
layer (Integard 264), a tie coat layer (Intersleek 731) and the finish coat (Intersleek 970). The
system has primarily been applied tometal, and it is not known if the system could be applied to
concrete. The system is resistant to direct impact but is susceptible tomechanical damage such as
gouging or scraping activities
Proper application is critical for the coating to work properly. The substrate surface must be at
least 3°C above dew point and between 21°C and 27°C for optimum application. The average
life span is five years. The long-term performance is unknown, but the system doeswell in short-
term performance. After a sixmonth exposure period inmarine waters, over 64% of the coated
surface was free of macrofouling in static conditions, and 97.4% was free of macrofouling in
dynamic conditions (Wells andSytsma 2009).
