Pasarell
Well-Known Member
Wolf,
I'm not sure of equating copper based AF with an antibiotic dosed AF (and the introduction of antibiotics to the thread was, I hope, an aberration) but in answer to your query on non copper based AF:
3 of which I know Trilux 33 (International) and Mille Dynamic Alu by (Hempel). Wattyly/Valspar/Sigma have Seapro Plus 100. If you have big pockets, PropSpeed. And for something completely different try sonic AF, check for an Australian coy called Jaycar who sell 'build your own' kits.
All these antifoulings ARE copper based in the form of copper (cuprous) thiocyanate. This makes them much less reactive with aluminium than copper oxide but also makes them less effective against shell fouling.
Wolf, you are possibly correct saying that copper will eventually be banned in antifoulings but there are no serious plans to do so at this time. A couple of ill informed attempts to do so have been made over the last 20 years but restrictions have generally been removed. Many studies have been carried out and, depending on the platform of the people involved, have variously shown copper to be completely harmless or dreadfully toxic! Consensus at the moment is that, even if copper is harmful to the environment, it is less so than than the alternative of massive amounts of fossil fuels being burnt to propel badly fouled shipping.
Copper comes in various forms in antifoulings. Main ones are in metallic form or as soluble combinations with other biocides in the form of copper oxide or copper thiocyanate. Metallic copper is a lot less bio available when in the ocean than the forms used in conventional paint type antifoulings.
Neeves mentions Propspeed as an expensive copper free antifouling. It is copper free and the generic type is produced by most of the major marine paint companies but usually for commercial shipping. The latest types of fluoropolymers are considered suitable for vessels moving at a minimum of 9 knots for at least 75% of the time. Propspeed is an older type that needed minimum speeds of about 15 knots to be effective. It works on leisure vessel propellors because it trades time in motion for absolute speed through the water. These products work by combining a low energy surface with a smooth finish that means fouling organisms have difficulty in adhering tightly. A smooth surface on its own will not work. If you leave them stationery for long enough they will become fouled and speed through the water will not remove that fouling