Ask the Expert Question-and-Answer Archive

by Ron Joseph

March, 2004

Zinc Oxide in Anti-Corrosive Primer

Q. Can we use ZnO (zinc oxide) as an anticorrosive extender in epoxy primer?

A. Zinc oxide pigments sometimes find use as an auxiliary pigment to help improve corrosion inhibition slightly. When used correctly the zinc oxide may increase the anticorrosion properties and impart an increase in film hardness; however, this may not always be the case. Proper balance and care must be taken when using and formulating corrosion resistant coatings. The type of pigment selection and the amounts used in the formula is of utmost importance.

Consult your pigment supplier for recommended levels of addition of the zinc oxide pigments. The amount you add is dependant on the other types of pigments that are used in the formula, you may be better served using a talc as the primary extender pigment.