The authoritative public forum
  for Metal Finishing since 1989
  

  -----

Galvanized versus e-coat

I am looking to galvanize a frame 8'x 12' 1/8 inch x 6" tubular steel. What are the difference or advantage of either galvanized or e-coat ?

Donald J. Taylor jr.
DCP - Detroit, Michigan
2006

---

Hello, Donald. Galvanizing involves the application of a heavy layer of zinc, which is a material which corrodes sacrificially to the underlying steel. So galvanizing is what we call a sacrificial coating. E-coating is an organic coating, rather similar to paint but with the advantage of full coverage in seams. Such coatings work by sealing the part away from the environment, and are sometimes called barrier layer coatings.

As a very general rule, and one person's opinion, galvanizing is preferable in rough service because even if the finish is scratched the protection remains as long as there is zinc left on the item. In lighter service, an organic coating may be preferable not only for economy but because it doesn't corrode and can therefore last longer.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2006

Hi Donald,
please be aware that the epoxy E-coat cannot resist the UV,
so for outdoor use double E coat is recommended(epoxy E-coat+acrylic E-coat).
However if the environment condition is harsh, the hot galvanization is more suited.

Shahrokh Yazdani
- Tehran, Iran
2006