Ask the Expert Question-and-Answer Archive

by Ron Joseph

November, 2008

Recoating Paints

Q. We painted a piece on site and the customer change his mind about the color. It is Dupont Imron 3.5 and has been applied for a week. We will be recoating with the same paint. Our supplier says we can paint directly on to it as long as we did NOT use accelerator, which we did not. My question is: With out sanding, "or scuffing up," what kind of addhesion will we have?

A. If the paint is only one week old I expect you will get good adhesion. I assume that the accelerator you were told not to use, is NOT Component B, the hardener?! In any case, if you have already completed the job you can check for adhesion by cutting an "X" through the coating using an X-Acto knife. Using the point of the knife try to lift the coating at the apex of the "X". If it peels off from the previous coat, you do not have good adhesion. On the other hand if it remains firm, I expect that adhesion is good.

Regards,

Ron Joseph