Some formulations are better for steel, some for aluminum.
Comparative tests have been performed to evaluate the corrosion-prevention capabilities of an experimental paint of the type described in “Water-Borne, Silicone-Based, Primerless Paints,” NASA Tech Briefs, Vol. 26, No. 11 (November 2002), page 30. To recapitulate: these paints contain relatively small amounts of volatile organic solvents and were developed as substitutes for traditional anticorrosion paints that contain large amounts of such solvents. An additional desirable feature of these paints is that they can be applied without need for prior application of primers to ensure adhesion.
As indicated by photographs of specimens taken after the 168-hour immersion (see figure), the experimental primerless silicone paint was effective in preventing corrosion of stainless steel 316, but failed to protect aluminum 2024-T3 and cold-rolled steel. The degree of failure was greater in the case of the cold-rolled steel. On the basis of visual observations, EIS, and corrosion- potential measurements, it was concluded that the commercial aluminum and zinc-filled nitrile rubber coating affords superior corrosion protection to aluminum 2024-T3 and is somewhat less effective in protecting stainless steel 304.
This work was done by Luz Marina Calle and Louis G. MacDowell of Kennedy Space Center, and Rubie D. Vinje of ASRC Aerospace. For further information, contact the Kennedy Innovative Partnerships Office at (321) 867-1463. KSC-12520