Aloha, fun & authoritative answers -- no cost, no passwords, no popups
(as an eBay Partner & Amazon Affiliate we earn from qualifying purchases)

Metal finishing Q&As since 1989

-----

Which is a suitable process before painting

Which is a better process to do before stoving epoxy/ enamel painting - Zinc phosphating or Zinc plating- why?

Thangaraj Vagulabaranam
product designer - Chennai, TN, India
October 22, 2009

Hi, Thangaraj. Zinc phosphatizing is far more common. Zinc plating has the advantage that you have a true cathodic protection system under the paint to protect from rust in the event of a scratch or chip, but it's more expensive and probably somewhat less reliable in providing good adhesion.

Regards,

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
October 22, 2009

Dear Sir,
You are right,
Zinc Phosphating will be best for this application.
Regards

Deep Mathpal
- Greater Noida, Uttar Pradesh, India
October 27, 2009

Dear Thangaraj,
Phosphating is the common [treatment] for before painting, if you doing the Zinc plating before painting, you will get better corrosion resistance. if, you are not having any problem in the salt spray go for phosphating

Kannan B
- Salem, Tamil Nadu, India
October 29, 2009

Hi Thangaraj

What is the material you are going to do painting, steel or cast iron etc?
Please explain your actual requirement on corrosion and adhesion for your parts.

If it is cast iron parts you can still have the choice of avoiding phosphating by replacing regular shot blasting as pretreatment process for your parts.
But make sure your corrosion and adhesion requirements are accomplished

Good luck

Vijendran Sudeendran
- Chennai, India
October 30, 2009

hi,

how would you rate (compare) zinc phosphating, iron phosphating and shot blasting on MS base surface on a 0-9 scale in terms of adhesion and corrosion resistance?

thanks,

Srujan Joshi
- Pune, Maharashtra, India
November 22, 2009

Hi, Srujan. You are asking for a quantitative answer to a question which I think only provides enough data for a qualitative answer, so I guess I'd answer: 9, 4.5, 0 :-)

Regards,

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
November , 2009

(No "dead threads" here! If this page isn't currently on the Hotline your Q, A, or Comment will restore it)

Q, A, or Comment on THIS thread -or- Start a NEW Thread

Disclaimer: It's not possible to fully diagnose a finishing problem or the hazards of an operation via these pages. All information presented is for general reference and does not represent a professional opinion nor the policy of an author's employer. The internet is largely anonymous & unvetted; some names may be fictitious and some recommendations might be harmful.

If you are seeking a product or service related to metal finishing, please check these Directories: