If I were to drive this Pantera down into the water at boat ramps in Long Beach harbor and let it soak for a while then I definitely should have used it. Still no mention of use with magnesium.
Product Description
Moeller Part #025472
Zinc Primer
Zinc Chromate: For aluminum surfaces above or below the waterline. This powerful primer etches into the aluminum, forming a strong surface/primer union that is resistant to corrosion. For professional use only.
Zinc Phosphate/Cold Galvanizing: For steel and iron surfaces, especially welded joints above and below the waterline. This corrosive barrier contains 95% of zinc, for maximum resistance against solvents & abrasions.