George King, Electrical & Mechanical Engineer, Dover Harbour Board
The lighting masts at Dover’s Western Docks range in height from 18 to 30 metres. Located on the quays which project into the harbour, they are exposed to wind, rain and salt water spray almost every day of the year.
As a result, some years after installation, the masts were in need of attention. On the side facing the prevailing weather, the zinc galvanised coating was showing signs of failure. When we carried out a comprehensive survey,areas of light rusting were found on exposed faces.
Aside from the safety measures required when operating at such heights, we worked closely with our paint supplier(Ameron PPG– and drew on more than 20 years of our own expertise – to formulate the correct sequence of specialist coatings to ensure long-lasting durability.Thorough preparation and removal of salt from the mast surfaces was critical.
Attention to detail. The masts were first cleaned by the application of Amercoat 57, an emulsion-based oil and degreasing agent. This was then washed off with hot water at high pressure (2800psi), with particular emphasis on removing all traces of salt contamination. Salt tests were carried out to ensure surfaces were free of salt contamination.
Rust stains and loose zinc coatings were carefully removed by hand using wire brushes, then patch-primed with Amercoat 4180 anti-corrosion primer. When dry, two coats of Amercoat 2136 Micaceous IronOxide paint (MiO) to achieve at least 150 microns were applied. A third and final coat of Amercoat 2143, a modified vinyl in BS-00-A-05 pale grey, was then applied at 80 microns.
The end result was a 225+ micron coating, with expected durability of more than 12 years.
Protecting lighting masts from the effects of the weather and salt spray required specialist coatings – and all our expertise
