3.5 Coating application

  3.5.1 The application of a coating should be a well planned activity, integrated in the shipyard's construction plans and carried out under controlled conditions to avoid conflicts with other yard operations.

  3.5.2 Coatings, including the primer and intermediate coats, should be applied on surfaces prepared and checked according to the provisions of 3.3 and 3.4.

  3.5.3 Coatings may be applied by spraying in controlled humidity and surface temperature conditions, in accordance with manufacturer's recommendations. Additional stripe coats, if required by the job specifications, should be applied by brush or roller to welds, edges and areas not easily accessible.

  3.5.4 Areas where the shop-primer is damaged in any way may be touched up in accordance with the manufacturer's specifications.

  3.5.5 Each coating layer should have the maximum/minimum thicknesses in accordance with the coating specification. An 80/20 practice may be adopted, which means that 80% of all thickness measurements should be greater than or equal to the nominal dry film thickness (DFT), and none of the remaining 20% is below 80% of the DFT.

  3.5.6 Care should be taken to avoid increasing the thickness in an exaggerated way. Excessive thickness could lead to dangerous consequences, such as solvent and thinner retention, film cracks, gas pockets, etc. Wet coating thickness should be checked during application.

  3.5.7 Each coating layer should be adequately cured before application of the next coat, in accordance with coating manufacturer's recommendations. Intermediate coats must not be contaminated with dirt, grease, dust, salt, over spray, etc. Job specifications should include the dry-to-re-coat times given by the manufacturer.

  3.5.8 Thinners should be limited to those types and quantities recommended by the manufacturer.