Where the
world gathers for metal finishing
Q&As since 1989


-----

Galvanized vs Cold Rolled: what is the best all-around for paint quality?

 

I am trying to put together a list of advantages and disadvantages of cold rolled, phosphatized, and painted steel over galvanized, phosphatized, and painted steel. I am trying to get as much information as possible about paint adhesion, weldability, environmental problems with galvanized, health risks and durability of the coating. Can you help me.

Davies Wakefield
- Two Rivers, Wisconsin

---

When improperly performed, galvanization can lead to paint adhesion problems, Davies, but when properly done, adhesion isn't an issue.

Powder coating on a properly prepared substrate is a good and very widely used finish. If severe scratching is unlikely, and reasonable life is good enough, you probably have no need to galvanize. But galvanizing is a sacrificial coating, and if you need something that will hold up despite severe scratching, and that will endure decades of tough exposure, galvanizing is your best if not your only choice. Galvanizing plus paint or powder is called a "duplex system".

Good luck with it.

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

---

---

Q. How can we differentiate CR & GA Sheets visually? Is there any method to check?

Arnold Bharathi
- Chennai, India
October 5, 2012