The cranes aesthetic appearance had become worn and weathered as well as showing clear signs of rust and corrosion. Remedial works were required to stabilise and treat the current corrosion whilst returning the cranes to their former bright and colourful appearance with a protective coating.
Firstly areas of grease and oil were removed by applying a biodegradable degreasing agent. Following this the entire crane was initially prepared using high pressure water jetting. This removed the degreasing agent as well as salts and contaminants whilst removing unsound existing coatings. Any areas of thick, built up grease were removed using a high pressure steam cleaner. Areas of laminate corrosion were further prepared using tungsten carbide scrapers, needle guns and scabblers. Removing the laminate corrosion is a vital stage of the preparation sequence as protective coatings are only as good as the surface they are adhered to.
Once prepared the protective coating sequence could begin. Due to the close proximity of vehicles, buildings and boats to the cranes, spraying was not an option and therefore brush and roller application was required. Any areas of bare steel were spot primed with a high solids aluminium primer. Once cured a full coat of the same primer was applied to the entire crane, paying special attention around nuts, bolts, angles and edges.
The next stage of the process was to apply an intermediate coat, prior to a full coat of Polyurethane top coat which would leave an excellent aesthetic finish as well as offering superb weathering resistance.
At various stages through the protective coating sequence, random salt tests were taken to ensure levels had not built up since the initial wash. If they were found to be too high, the steel would be washed down again as chloride contamination would lead to premature failure of the protective coating system. The climatic conditions were regularly checked, paying particular attention to the application parameters as detailed by the manufacturer such as relative humidity and due point.
Throughout the project all works were carried out as per the Method Statement, Risk Assessments and COSHH Assessment, paying particular attention to wind speeds whilst working from MEWPs over or near water.