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Are there other coatings would be reasonable other than galvanization?

Question 2 of 2:
Given that galvanization has been made much more expensive due to the higher costs of zinc, can anyone provide reasonable suggestions in regards to alternative coating applications? Would powder coating be a reasonable, cost effective alternative for a barrier product something like highway guardrail? Would it be reasonable from the production-side, as it includes thousands of feet and thousands of tons of the material that would have to be separated in order to be totally coated? What is the average life span of a powder coated section of standard 16ga steel in an outside environment, with no exceptional exposures to corrosive agents? Is it comparable to galvanization?

Also,
Are there any other questions that I should be asking regarding this situation?

Thomas Calton
surplus - Rutherfordton, North Carolina
2006

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The basic difference between powder coating and galvanization is that powder coating is a barrier layer coating and galvanization is a sacrificial coating, Thomas.

Barrier layer coatings can be great in corrosion resistance; look for example at the paint on a new car and how well it stands up for years . . . as long as it's not scratched. But sacrificial coatings anodically protect the item despite scratches. If your product truly will be like a guardrail and likely to be seriously scratched, you probably won't find a substitute for galvanization. If scratches are uncommon and not deep, a properly pretreated powder coating may be just fine.

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

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As a company involved in both these processes, I can tell you that they have a similar cost, so if cost saving is your objective for moving from galv, then it is unlikely to realise much saving.
The economics might be different in USA from UK, but it seems unlikely to me. Of course there will be "el cheapo" powdercoaters, as the entry cost is rather low into that process, whereas the high capital cost of setting up a galv plant means there are few discounters.

Geoff Crowley
Crithwood Ltd.
Westfield, Scotland, UK

2006

I agree with Ted, but if you want to use paint your best bet would be to use pre-painted from a coil line. A variety of treatments and coating options are available and the volume would not be a concern.

Ronald Zeeman
Coil Coating - Brampton, ON, Canada
2006