An assessment carried out by Plymouth Marine Laboratory (PML) has found that Coppercoat leaches significantly less copper over five years than the other coatings tested.
This means that Coppercoat’s total product loss – over a five-year period of constant immersion in an area of strong tidal flow with mineral scour – was just 1/14th of that shown by traditional antifouling paint. Expressed as a percentage, Coppercoat demonstrated a coating loss of approximately 4.3% over the five years; in comparison, the conventional antifouling paints on test lost 90-100% of their copper-containing topcoat.
From the tidal flow rate measurements taken at the test site, PML Project Coordinator, Dr Tom Vance, and his team calculated that the test equated to subjecting the coatings to a voyage of more than 283,000km at a speed of 3.5 knots over the five-year period.
In the in situ trial of protective coatings – conducted by the Energy Technologies Institute – two 3.5-tonne test pods covered in panels coated with a wide variety of antifouling systems were submerged in a tidal stream in the Fall of Warness, Orkney, Scotland. Conventional (self-polishing) antifouling paints typically exhibited a mean product loss rate of 0.099µm/day, while Coppercoat showed a mean product loss rate of just 0.0071µm/day. And when the PML team examined the copper content alone – the active biocide – the loss from the Coppercoat was found to be a mere 1.42µg/cm2/day. The full report is available online.
These results help to illustrate why the Coppercoat officially supplied for the race boats on the 2017/18 Clipper Round the World Race yachts looked as good as new when the boats were lifted out following their 40,000NM circumnavigation.