Finish For Exterior Work | Problem Solving | Forum

Powder coating is TERRIBLE for endurance.
It looks great for the first few years, then, when it fails, its a huge mess, really expensive to redo, and will drive you completely nuts.

Dont use it for exterior stuff that you expect to last more than about ten years. Because, if you are lucky, and you dont have it anywhere near salt water or salted roads, powder will last ten years.

But once it fails, and it always does, it peels, randomly, and cannot be touched up on site except with real paint, which doesnt look the same. So you have to take it out, bake and/or sandblast it, and then recoat.

The best paints for outdoors are probably two part epoxies, over zinc rich primers. Sandblasting is pretty much required, then primer, then a couple of top coats. Professional painters can make it look good, not gloppy.

But all older painted ironwork, like, for example, Art Noveau stuff, has been wire brushed and sanded and repainted many times over the course of a hundred years- its the nature of the material.

Cheap paint is cheap. All consumer grade waterborne stuff is pretty crappy, in my experience. If you have no budget, and you want a decent medium term paint, oil based stuff like rustoleum or hammerite are the best consumer grade stuff you can get.
Pros use stuff like Tnemic-
http://www.tnemec.com/
figure at least a hundred bucks a gallon.

Finishing steel is an art, and it is not cheap.
I have seen some high end smiths have the work galvanized first, then cleaned up, then etched, primed, and painted with a two part epoxy. Paint can be a quarter of the sales price, or more.
Thats why in places like Hawaii or Florida, they dont even use steel- most all exterior forgings are aluminum. or stainless.