Paints & Coatings Resource Center

Ask the Expert Question-and-Answer Archive

by Ron Joseph

June, 2005

Hammertone Finishes

Q. There is a problem while painting hammertone finishes. I used to coat air compressor body in air drying hammertone finishes in shades of green and light blue. The paint system, I follow is NC based grey primer --> allow it dry for 4 to 6 hours --> apply air drying hammertone finishes. --> keep for drying for 4 to 6 hours and then to further assembly. The problem, after assy. in few days time, it shows peeling off problem, especially at outlet end of compressor body. It also loss of hammertone. Will you please guide me to solve the problem ?

A. Thank you for your email. Unfortunately without seeing exactly what is happening I can't help you. Some fast-drying lacquers lift when the intercoating time is in a critical range. This usually does not occur with try N/C lacquers, but perhaps there is something in the formulation of your lacquer that results in this lifting defect.
Try changing the intercoating time between primer and topcoat to less than 4 hours (1 2, 3 hours) and also to more than 6 hours (8, 10, 12 hours). This might be the cause of the problem.

Surface contamination could be a problem, since you find the peeling only at the compressor outlet. Are you testing the compressor at any time before or after the coating has been applied? What is the temperature of the surfaces where the peeling is taking place? Is it possible that after assembly the compressor is tested and oils or other contaminants in the air deposit on the surfaces that you previously painted?

If you absolutely can't solve the problem I would be happy to try to assist you on a consulting basis, but we can discuss this if my recommendations above do not solve the problem.

Best wishes,

Ron Joseph

What's New | About PCRC | Compliance Assistance | Regulations | Technical Info | News | Homeowners | Search | Disclaimer | Home

©2012 Paints and Coatings Resource Center