three years ago, Corrocoat usA was called in when a galvanised electricity transmission pole was found to be suffering from significant corrosion. the pole was situated in a tidal splash zone and was subject to continual exposure to seawater.
On examination it was found that the sacrificial zinc lining around the base of the pole was already consumed and that the steel pole itself was corroding at an increasing rate. If left, the pole would suffer significant steel loss and would likely require expensive replacement.
Corrocoat USA was asked to prepare and protect the 48” (1.2m) diameter pole to a height of 12ft (3.7m) and to complete this work in a tidal zone – quite a challenge! Zip E was selected due to its excellent barrier protection, great adhesion and fast drying time between coats of between 10 and 15 minutes. This was critical given the inevitable time deadlines imposed by an unstoppable tide.
The project was completed over three consecutive days working from a barge. In order to access the site, the application team had to travel to the site at high tide and wait for the 90–120 minute window to prepare the pole and apply the coating. The work included removing marine growth before abrasive blasting to SSPC SP6, 50μm profile and the application of Zip E in multiple coats to achieve a dft of 600μm. Once gelled Zip E continued to cure underwater and could be over coated the next day.
The pole was inspected recently and was seen to be in a “like-new” condition. Corrocoat USA expect the coating to last 10 years before any maintenance is necessary and the client has requested that 17 more transmission poles suffering similar corrosion damage be treated. Corrocoat USA have since quoted to use this specification on poles prior to installation.