Coating Application, Inspection And Maintenance

Once the coating has been chosen, it is imperative that it be applied correctly to attain its maximum corrosion protection benefits. Surface preparation (often blast cleaning) and coating application is, even while properly done, dusty, dirty ,demanding work, proper access, heating , lighting and ventilation should be provided and workers should have safe work practices and equipment for the work intended.

Primarily a “pre surface preparation inspection” must be made. Coating application is in the most basic terms the preparation of the surface to receive paint and the application of the paint in an appropriate manner to the specified thickness. The surface preparation specified is predicated by the coating system to be applied. Usually it is a good idea to specify a “Standard” surface preparation method. The coating thickness must be achieved in one or more coats (usually three) and care must be taken to assure that there is no contamination among coats.

There are an extensive variety of inspection instruments, aids, and standards that might be utilized to assess the quality of the coating system. These include devices for assessing the cleanliness of a prepared surface, the depth of a blast cleaning anchor pattern or profile, and eddy current, several magnetic and destructive thickness gages. After application, adhesion tests & tests for pinholes and other discontinuities might also be specified.

Afterwards as the coating breaks down and deteriorates because of the effect of the environment, schedules inspections are desirable to assess the extent & rate of coating breakdown. Spot touch up repair must be accomplished at localised areas of failures prior to drastic deterioration of the whole coated surface. If the “planned maintenance approach” of periodic spot touch up, followed rarely by a full coat over the entire coated surface, is done, the extensive costs of total surface preparation might be avoided, sometimes for periods approaching more than years.
It is significant that the entire coating sequential flow be maintained from starting to end-definition on the environment, selection of the appropriate coating system, appropriate surface preparation and application, inspection and periodic maintenance & repair. If all of these operations are carry out intelligently and competently, corrosion protection by coatings might be economically attained for long periods.