Ask the Expert Question-and-Answer Archive

by Ron Joseph

June, 2001

Corrosion Inhibitors and CARC Paints and Coatings

Q. We manufacture Volatile Corrosion Inhibitors (VCI). I was wondering if a VCI (amine compounds) can be used in paint as a primer coat which will later be covered with CARC paint? Another question is if a spare part is painted with CARC paint, can it be placed in a VCI bag for storage without affecting the CARC character required by the military?.

It would be good to manufacture a VCI-CARC paint but the testing, etc., would take a long time and require paint expertice that we don't have. Do you know anyone who might be interested in a partnership?

A. Your first question relates to the ue of amines in the primer. Most corrosion-resistant primers already contain corrosion inhibitors and you would need to have a reason for wanting to add another inhibitor into the primer. To the best of my knowledge, a volatile corrosion inhibitor (VCI) deposits as a microscopically thin film on the metal surface. If I am correct, what would the corrosion inhibiting mechanism be if the VCI were added to the primer?

Regarding your second question, I don't think there would be any harm to the coating system if you were to place a CARC-coated product into a sealed bag that contains VCI. I'm sure this has been done many times in the past; however, in my opinion it would be prudent for you to conduct tests to confirm this before selling the concept. Alternatively, look in the literature to see who has already reported the results of such exposures.

Finally, how would the use of a volatile amine provide corrosion resistance to a substrate if it were incorporated directly into the CARC topcoat? Have you actually tried this, and do you have any results to show a benefit?