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  for Metal Finishing since 1989
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Electrodeposition Quality issue

2005

Good day mr. editor

My name is KC Tan from Malaysia, I would like to place an inquiry regarding some quality issue that happens frequently in my company. I've cracked my head several months but unfortunately am unable to solve the problem.

The defects only happened on the big surface especially on steel surface (my company runs aluminum & steel parts) but not aluminium. after my study, I think is from ED tank ( all of the chemical already in spec.included the ED tank). I observed that the part just after the ED tank with the water mark (dot type) o the part unable to removed after the UF spray & DI rinse.My another chemical is Zinc Phosphate.

Is very obvious before goes to oven but however after oven baking the dot mark still can be seen on every corner of the part. my oven temperature is 200C - 240C.

Hopefully you can give me an idea how to tackle this issue.

Very much thankful of your kindness.

Regards,

KC Tan
- Desa Cemerlang, Johor Bahru, Malaysia

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2006

Without looking at the defect it is difficult to help but there are defect to which we refer as pinholes or craters.

There occur due to either the presence of oil on the surface or due to an improper pigment to binder ratio.

Since other parts are not having the problem, that rules out the p/b ratio and leaves us with poor cleaning as a possible cause.

To check that out, when the part leaves the pre treatment line, check it as soon as it comes out of the last rinse tank. If you can see the same pattern of 'dots' you might be able to get to the root of the problem.

adv.
You can also click on our company link below and email me an image of the problem.

Best of luck.

Gurvin Singh
Mohali, Punjab, India

adv.