Port machinery
Container handling cranes — repainting without removing the booms
Boom and girder sections too large for a galvanizing bath were blast cleaned in place and coated with cold spray zinc plus a metallic sealer. Work was phased around vessel calls, with two to three girder sections released per shift, so no crane was out of service for a full day.
Why hot-dip galvanizing was not an option
Crane girders and cross beams run past forty metres in single pieces, well beyond any galvanizing bath, and dismantling a ship-to-shore crane for transport is not a real option. Meanwhile the terminal keeps working: every day a crane is out of service has a cost measured in berth windows, not in paint. The original zinc-rich epoxy system had served about eight years, with breakdown concentrated where water stands and where the spreader and trolley rails wear the coating mechanically.
System selection
ZD96-1 with ZB18-12 metal sealer, 120 µm total. Thinner than the bridge system on purpose: a ship-to-shore crane sits in marine atmosphere but not in the splash zone, and it has scheduled maintenance access that a bridge over water does not. The metal sealer replaces both intermediate and topcoat — one less coat, which matters because the constraint here is not film build but how many work steps fit into the window between vessel calls.
How it was applied
Work was sequenced around vessel calls: two to three sections per shift, with any section finished during the day taken through to sealer the same day. No bare zinc was left overnight — dew point swings at the quay will start alkaline reaction on an unsealed zinc layer, and the next coat then goes on over a contaminated surface. Scaffolding travelled with the section rather than being built around the whole crane, and blasting used vacuum recovery so grit and dust did not drop onto the rails or into the machinery house.
Acceptance and follow-up
Section-by-section acceptance: thickness and pull-off adhesion per section, released for handover once it passed, so the scaffold came down as work progressed rather than at the end. After the crane returned to service, a visual survey covered the spots that are always missed — under the rails, the machinery house roof, and the tie-rod nodes where water runs down and collects.
Products used
Other projects
Tank farm — external shell and wind girder refurbishment
Twelve tanks in an inland refinery had coating breakdown at the shell course below the wind girder, where water collects. After surface preparation to Sa 2.5, cold spray zinc restored the base layer on the repaired bands; the remaining sound coating was feathered and overcoated, so only the failed bands were replaced rather than the full shell.
Cross-sea cable-stayed bridge — steel box girder and tower
Marine atmosphere at C5-M. Cold spray zinc was applied as the base layer on the steel box girder and tower segments that could not be sent to a galvanizing bath, then sealed and finished with an aliphatic polyurethane topcoat. Application was carried out in the fabrication yard on completed segments, avoiding post-assembly touch-up over the water.
Not sure which grade fits your environment?
Send us the structure, the steel condition and the corrosivity category (C2 to CX). We reply with a coating system, film builds and a delivered price.