New construction vs maintenance painting of ships
A fact of life in the maritime industry is that ships need to be painted often. Their continued useful service depends on frequent application and inspection of protective coatings.
The importance of getting new construction coating right cannot be overstated because it has a direct impact on future maintenance jobs. And it’s just as much about effective project management as it is about proper application.
New construction coating
The first protective coating a ship gets is a protective primer (usually short oil alkyds, inorganic zincs, waterborne epoxies, or iron oxide vinyl / phenolics) applied before assembly. This coating is designed to protect against flashing while parts undergo welding, fabrication, assembly, or other operations.
Project management is key here, as the correct application of a ship’s protective coating is the best way to secure a future of relatively routine maintenance paint jobs. But this goes beyond proper surface prep and coating application.
With so many other tasks taking place during new ship construction, project managers need to be mindful about the order in which jobs are completed.
For instance, having welders or other crews work behind paint crews should be avoided. Welding —or any other assembly or fabrication— on parts already coated could damage the coating. Managers would need to check coatings to make sure they weren’t damaged and order repairs if they were.
In the worst-case scenario, operations that could damage coatings may be carried out after painting and without subsequent inspection. Everything might look fine, but an undetected corrosion attack may be just beneath the surface.
There are two kinds of maintenance jobs: Those done while a ship is dry docked and those done while at sea.
Coating while underway is difficult and inconvenient, especially in an age of reduced crew sizes and cost cutting. But an advantage it has over working while docked is that ships are still earning revenue while the maintenance is ongoing. It’s sometimes a viable option, but if coating is done while a ship is at sea, that comes with added worker safety and supply storage rules that may be difficult or expensive to follow.
Maintenance coating of critical components or areas should be done while vessels are dry docked so that crews have all they need to do the most thorough job.
For example, coating inside tanks should be done while docked because these jobs are usually best done by crews that specialize in confined space projects. In addition, coating in tanks and other interior spaces is best done while docked because it’s easier to control the environment and access of the workspace compared to if these jobs were attempted at sea. Any underwater hull maintenance or antifouling application can only be done while docked.
Emergencies are also easier to respond to when a ship is docked instead of cruising in the middle of an ocean.
Setting up for success
Protective marine coatings are most successful when they’re done the right way. When planning a new construction or maintenance coating project, consult with coating manufacturers ahead of time. Major marine coating manufacturers often offer crew training programs. Similarly, the U.S. Navy assigns special Corrosion Control Application Teams (CCATs) to train sailors on proper coating application.
Getting the right contractors on the job is critical. The nationally recognized QP 1 accreditation program evaluates field application skills of contractors working on industrial and marine structures. The QP 5 program evaluates inspection companies to assure they provide consistent quality coating inspections. And, for a variety of education courses developed and designed specifically for those who work in marine environments look to AMPP.