The Problem-Solution Series: Part 22

Pestered by Pinholes

Problem:
Pinholes have formed on the surface of the coating. What do you do?

Origin/Cause:
An incompatible powder is contaminating the coating. 

Solution:
Clean the application equipment when you are changing the powder from one powder to the next. 

Second Origin:
Out-gassing is producing pinholes. Luckily, there are many possible solutions to this problem. 

Solution 1:
Determine the metal porosity. Then, adjust processing to minimize the effects of the metal porosity. 

Solution 2:
Adjust the dry-off oven temperature to ensure no moisture is on the part. 

Solution 3:
Check the powder for moisture introduced in reclaim, from air supply, or from the virgin powder. 

Solution 4:
A thick film may be causing out-gassing. Reduce the film thickness so that the gas can escape through the surface during cure. 

Solution 5:
Urethane powder coatings may emit a blocking agent. Due to this, pinholes may occur on the surface at a film build above 3 mils.

For additional information on powder coatings, visit our website at tcipowder.com. Feel free to contact us today to have someone from our experienced team answer your powder coating questions or to see how we can help you with your powder coating needs.