As for chemicals you only need two things.
How to age galvanized metal siding.
Clorox clinging bleach gel toilet cleaner i tried about 5 brands this worked best and regular old baking soda.
To age galvanized metal start by sanding it with 80 grit sandpaper until it no longer looks shiny and slick.
Old towel or rag.
Place lathered bucket outside or in a well ventilated area for 2 4 hours or until dry.
Soak the rag in the patina solution wring it out just a bit and cover your item with the wet rag.
Grab an old rag make sure it s large enough to drape comfortably over the entire surface of your galvanized victim.
Corrugated metal roofing you can find this at any home improvement store clorox toilet cleaner with bleach.
How to age corrugated metal roofing.
The longer it sits the more aged the piece will look.
With a piece of steel wool work cleaner into a lather covering all of the exterior including handles and crevices image 2.
As you sprinkle the salt you can see it begin to work with the hydrogen peroxide.
This solution will discolor wood surfaces and probably many other things so be careful.
Well i mean age galvanized metal that is.
With a couple of common household products and a couple of tools you can get all aged up in minutes.
First be sure to wear gloves.
Supplies for aging galvanized metal.
Then put the metal on a plastic sheet in an open or well ventilated area and put on safety glasses gloves and a long sleeved shirt to protect yourself from the chemicals.