摘要: |
The Surface Preparation and Coatings Panel (SP-3) selected and defined this project to gain insight into the parameters that govern the standardization of procedures, certification and testing methods for welding through preconstruction primers. Steel is processed in most yards to remove mill scale, rust, and any surface conditions that can affect fabrication and welding processes. If steel were delivered 'clean,' and not be exposed to weather conditions during storage, fabricated and welded into assemblies and blocks, then primed, we would have the IDEAL. Just In Time Process Flow, and preconstruction primer would not be necessary. Generally, the yards must clean steel, and, protect the surfaces with primer during storage and fabrication. When the industry use of automatic welding is considered, the issue of the project takes on the ultimate importance. Here, the larger costs of ship construction are driven by not only the high production welding work volumes, but also the steel surface areas to be protected throughout the fabrication/assembly cycles, as well as, the on-block and on-board cycles. This protection must be effective prior to application of other paint system coatings. Large costs result from re-blast, conditioning, and re-priming where the original surface protection is insufficient. / NOTE:Final rept. |