SNAME Panel SP-3 Surface Preparation and Coatings.

摘要

In the present climate of increased federal and local regulations on alleged pollution producing manufacturing operations, open abrasive blasting is being scrutinized for possible further regulation. Outright prohibition may be the final outcome. First indications are that citric acid cleaning processes offer a partial solution to the pollution problem. These cleaning processes are potentially nontoxic and biodegradeable. Spent solutions can easily be disposed of by treatment in a boiler or other incineration device. Another advantage of citric acid is the relative nonaggressiveness of the acid to the base metal. The oxides (rust) are removed with little or no effect on the underlying steel. Realizing the potential merits of citric acid cleaning, the 023-1 panel of SNAME developed a proposed research and development project to investigate the suitability and acceptability of citric acid cleaning processes in new ship construction. The first step of any proposed new surface preparation must be to determine the compatibility of present state-of-the-art coating systems with surfaces cleaned via the proposed cleaning process. This project, Cleaning of Steel Assemblies and Shipboard Touch-up Using Citric Acid (Phase I) , accomplished the above stated goal. Based on the testing results contained within this report, in most cases, coating systems applied over citric acid cleaned steel performed as well as or superior to the same coating system applied over abrasive blasted steel. Stated another way, most coating systems appear to be compatible with citric acid cleaned substrates.