External green radiator corrosion

[Fordman487]

I have a green corrosion-like substance starting to appear on the OUTSIDE of my brass/copper radiator. Someone suggested this is a result of the manufacturing process chemicals and oxidation. What is this and what's the best way to clean this off,...vinegar, simple green, paint over it?

 

[alanwoodieman]

very minor leak, evaporating before you see it?

 

[Lawson Cox]

Oxidation. I sort of agree with Alan if it is in a car. I have a NOS core that is almost completely covered with greenish/gray oxidation. Spray it with vinegar and see what happens.