Galvanizing Plant

I like that...I'm on 'The Board'!

re: galvanizing facility..not that I know of but you can call Walsh Metals to see what they say. They do a LOT of fabrication.
Walsh Metals website

there is a spray paint, called "instant galvanize" which is a high chromatic and zinc based primer.
last time I purchased a can it was about $7.50 each...!
It is silver in color, flat to dull surface finish, fairly well matches dipped galvanized items...and was originally intended for repair of boat trailers that see constant water dipping.
You might be able to find it at an automotive paint distributor.
To protect from local environmental corrosion...any primer that is high in zinc based metals, either red or another color will do a reasonable job in the islands...and looks fair if covered with " silver" colored spray paint.
EPA regulations for dip galvanizing are extremely stringent and I am sure that trying to open such a process on the island would never pass local requirements.
I have worked for more than 40 years in corrosion protection of metals, including hot dip galvanizing...and the "instant galvanize" spray is by far the least expensive but the most highly protective coating for normal household protection for the cost spent...especially for getting into hard to reach areas; like on trailers or framework on an automobile.
My second choice would be two part coal tar epoxy with a silver top coating!
You can also do a wonderful job of fabrication with aluminum...and after a fast garnet paper sanding (or glass blasting) it needs immediate coating with yellow chromate paint..then you can spray any quality enamel finish color paint to your needs...oxide primers will not work on aluminum..
The yellow chromate bonds to the activated aluminum surface (sanding or glass blasting) making an acceptable base for enamel finish.
Same for structural steel...glass blast, do not sand blast, and prime the surface immediately...then do your finish coating, silver if you wish.
Sand blasting actually impacts the metal surface and can actually promote oxidation (rusting) with the transmission of moisture in the sand blast material.underneath the primer!
If you fabricate from pre-galvanized steel or iron...any weld joint needs to be properly ground clean of any pregalvanization prior to welding, and then re-cleaned (glass blasting) with a heavy oxide primer and silver topcoat to match balance of structure. Never coat when the joint is still hot to touch from welding or blasting!
Hope this gives a little insight to DIY protective coating.

NOW THAT IS WHAT I AM TALKING ABOUT!!!!!!!😎

Thank you, great job. Peace.