Sound technical content, curated with aloha by
Ted Mooney, P.E. RET
Pine Beach, NJ
The authoritative public forum
for Metal Finishing since 1989
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E-Coating peels from electrogalvanized steel
Q. We have a part, which base material is steel-electrogalvanized. This part is sent out to be E-Coated in black.
The problem we are having is that 1/2 of the order returns with heavy orange peel and the other comes good.
My question is what is the cause of this variable?
- Chicago, IL, USA
2005
A. Have you compared the thickness on both good parts and parts having heavy orange peel ?
Manish Dhyani- India
2005
A. Is there any chance that some of your raw material (electro-galv.) has had some type of passivation treatment ?
ALAN THOMAS- Chandler, Arizona, USA
2005
A. Some surfaces/substrates such as electrogalvanised can cause poor appearances; by changing to an electrophoretic paint which has slightly more flow properties (electrophoretic paint does flow to a degree once inside the oven) a lot of these poor appearances can be overcome. Talk to your electrophoretic supplier about this
Anthony Wagstaff- UK
2005
A. Make sure you still phosphate the Galvanised Steel before E-Coat. It won't adhere well if you try coating it direct.
Khozem Vahaanwala
Saify Ind
Bengaluru, Karnataka, India
2005
Printing is not sticking to electrogalvanized sheet
Q. Hello sir,
We use electrogalvanized steel sheet 1.5 mm thick to produce power supply unit, so we need to print on the sheet. Sometimes we face more problem of peel off. I think the paint adhesion is not sufficient for electrogalvanized steel. So kindly advice me which paint is suitable for the electrogalvanized steel?
Now we baking the material for 30 minutes,at 180 °C; kindly advise me.
Gopi nath.H
- Mumbai, India
March 11, 2015
A. Hi Gopi. We appended your inquiry to an earlier thread. Khozem has explained the problem: you need to phosphatize (or at the very least, etch) the surface for any paint to stick.
Regards,
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
March 2015
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