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"Defects found in powder prime on steel"
November 1, 2018
Q. I have metal surfaces with PPG prime powder coating and I keep finding these clear circular spots in the primed surface. They are almost like a round clear crystal and if I use a tool I can kind of pop it off of the surface. Any idea what I am seeing here?
defect observation - Masury, Ohio, USA
A. Hi Will. It's certainly an unacceptable situation, and it looks like the corrosion resistance as well as the aesthetics would be impacted. It would appear to be a contamination problem of the surface not being clean, although I suppose that something could have gotten into the powder.
Unfortunately, identifying yourself as a "defect observer" is keeping everything extremely abstract. We don't know if you're a homeowner putting siding on your house and trying to determine whether to continue or demand a refund, or an operator running a coil coating line and concerned about what changes to make to fix what you are producing, or a buyer scouring for seconds and trying to determine how acceptable they are, or what. Please explain who you are and your situation.
Ted Mooney, P.E. RET
Aloha -- an idea worth spreading
finishing.com - Pine Beach, New Jersey