Summary for e-coating on anodized aluminum Discussion
E-coating on anodized aluminum is generally not recommended, and the thread suggests it is unlikely to work in practice. The question asked whether ED coating over anodized aluminum, before sealing, is possible and whether it would improve performance. In response, Aluminum How-To said he had never heard of anyone doing it and noted that anodized aluminum is no longer conductive, so electrocoating would be highly specialized; he also said it is hard to judge any performance benefit without a specific goal, though anodized surfaces are already harder and more wear-resistant than e-coat or bare aluminum. A second reply from Alok was more direct: anodizing is a poor pretreatment for organic coatings, adhesion would be problematic, and e-coating requires a conductive surface, so he concluded that you cannot do e-coating on anodized aluminum.
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— this entry appended to this thread by editor in lieu of spawning a duplicative thread
Q. Can you ED Coat over Anodised Aluminium (Before Sealing)? Is it possible and is it preferable to improve performance?
Anuj Arora
– NOIDA INDIA
December 8, 2022
“Electrocoats: Formulation and Technology”
by Bruggemann & Rach
on Amazon
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A. Hi Anuj. I’ve never heard of anyone who is doing it — probably because electrocoating is done on conductive substrates, and once aluminum is anodized it is no longer conductive, so the process would be quite specialized.
It is hard to say whether it would improve performance over alternative treatment sequences without knowing in exactly what way improved performance is sought. Certainly the surface of anodized aluminum is harder and more wear-resistant than e-coat or raw aluminum without quite a bit of development work.
Luck & Regards,
Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com – Pine Beach, New Jersey
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⇩ Similar, related, Q&As — oldest first ⇩
Q. I want to know whether we can do e-coating on aluminium anodized sections of 1.6 m x 60 mm dia. section. If yes,then how?
Alok Jain
– Noida India
November 29, 2014
Aluminum How-To
“Chromating – Anodizing – Hardcoating”
by Robert Probert
You’ll love this book. Finishing.com has sold a thousand copies without a return request 🙂
A. Hi Alok. Few things are actually impossible, but e-coating of anodized aluminum sounds to me like it has a double whammy going against it:
In the first place, anodizing is a poor pretreatment for organic coatings, and adhesion would be problematical.
Secondly, anodizing is an electrically insulating (non-conductive) coating and the principal behind e-coating is that you need a conductive surface that becomes insulative as the e-coating builds up. So I’d say, no, you can’t do e-coating on anodized aluminum.
Regards,
Ted Mooney, P.E.
Striving to live Aloha
finishing.com – Pine Beach, New Jersey
Need quick confidential answers? $25
Need project assistance? $100/hr.