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In 1979, a test was initiated to evaluate the use of dissimilar metals in close conjunction with each other, including aluminum, stainless steel and an Al-Ti-Al laminate heat exchanger, in a closed deoxygenated water coolant loop over an extended vehicle life. The closed, sealed loop contained distilled, deoxygenated water initially supplied at <0.3 ppm by weight dissolved oxygen. The system involved a variety of dissimilar metals, including 300 series CRES, 6061 aluminum alloy, gold-nickel braze alloy and thermometer bi-metallics. Coatings were also used to provide added protection to the aluminum. A stainless steel to aluminum transition tube was sandblasted, passivated, alodined and coated with P.D. George epoxy coating No. 923. The heat exchanger was of plate fin construction with parting sheets made of an Al-Ti-Al laminate designed to prevent through wall pitting in case corrosion attack initiated.