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Bubbling / swelling in ED coating
November 1, 2009
we are manufacturers of sheet metal parts and having a ED coating shop in-house where we are coating brake parts. Recently we have found parts having bubble / swelling like formation near a riveted area. 10 ~ 15 % parts are like this.

What can be the cause and remedy ?
SHARAD GUPTA
buyer - India
Are those parts hung so that the defect is vertical? If so, you might have a pretreatment problem. It looks like a drip line where liquid would concentrate. If so, that usually points to a cleaning/treating/rinsing issue.
Christian Restifo
- Pittsburgh, Pennsylvania
November 10, 2009
December 27, 2009
Hi
by seeing this picture one of the probable reason could be
1) rust on metal surface.
2) bubble adhere during paint deposition on that particular area.
hopefully it would be helpful to you
Thanks
SURYA PAL
- DELHI, India
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