epoxy coating vs galvanizing

I am not sure about epoxy coatings on steel wires but I believe it must depend on what you do with them.

If the wires get rolled on and off or are rubbing all the time, I think the epoxy coat will eventually come off whereas the galvanised material could perform better.

If it is just a matter of esthetic's you need to consider the finished result and epoxy can get any colour you want.

My friend has made himself a bull bar for a transit van which has got a hitch ball on it and also carries the roof rack if needed. This was 12 years ago and the van is now rotting away merrily but the galvanised bull bar just sits there still grinning. It has never had a lick of paint so it is not pretty but it looks like it will last forever.

About "in highly corrosive environment, you may want to use epoxy coatings"，can you give me some data to illustrate your statement? thanks

It depends on the type of service. Galvanizing is extremely durable. A very large bridge in New York City is suspended with galvanized steel cables that have no other coating. The cables are 'as-new' today, after more than 100 years of service!

I fully agree and a GA for you. It all does depend on service but we are not told what this is as yet

Hope we do soon.

Maybe galvanized steel wire cables are ok for many cable supporting bridges, but there are still a several bridges that have to change the cables because the galvanized wires are corrosive highly.

So I'd like to collect the information about epoxy coated steel wires on corrosion resistance in order to study the improvement of cable performance.

can somebody help me? thanks

I must admit that I do not know much detail about the process so it could perhaps be that there are different ways of galvanising.

The bull bars I mentioned were hot dipped and are as such a coating rather than a conversion coating. Maybe if you electro plate a galvanic solution you get an even better result.

Sorry, stumped here.

as someone said the final decision depends on factors like: design life, ambient corrosivity (marine exposure, industrial...), criticality of the item (risk associated with a rupture), accessibility for inspection and maintenance of the paint if necessary.

There is also a new approach in critical item where galvanizing plus coating is used to achieve the best protection in very corrosive environments..

this one the nost useful website on galvanized steel.. you can find a lot of informations..

http://www.galvanizeit.org/

hot dip galvanized steel vs paint

http://www.galvanizeit.org/resources/files/AGA_root/pdf_files/pubs/C-GvsP-04.pdf

Hot-Dip Galvanizing vs. Zinc-Rich Paint

zinc coating life predictor

http://www.galvanizeit.org/resources/files/AGA_root/pdf_files/pubs/PR-SLC-05.pdf

hope this help

S.

Corrosion Control & Corrosion Protection website