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Defects found in powder prime on steel

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?

60887-1

will Leland
defect observation - Masury, Ohio, USA
November 1, 2018

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.

Regards,

Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
November 2018

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