There are any number of metals at SendCutSend that weather just fine without any protection. Stainless steel and titanium, for example, are among the most corrosion-resistant of all materials. On the other hand, brass and especially copper take on a rich patina after a few years in the rain and sun. And while leaving mild steel exposed to the elements will soon lead to a rusted, flaky surface, steels such as Cor-Ten weathering steel (the name gives it away) form a rustic, rust-like finish that will last for decades.
Bare metal is perfectly fine for many applications, signage, sprockets, and BBQ grill grates among them. Sometimes, though, a little color is needed. The laser-cut logo for Pepe’s Taco Truck would surely look best in a bright, jalapeno green. The owner of Sarah’s Day Spa might want her metal privacy screens colored a calming ocean blue, while the lead singer of the garage rock band Drunk Plumbers insists the stage backdrop be painted what he calls “screaming fuchsia.”
The good news is, all these colors and more are readily available. Even fuchsia. Before breaking out your Sherwin Williams color wheel, however, you’d better figure out whether you’re going to paint these various works of art, or powder coat them?
Paint needs no introduction. In fact, most of us have ruined a favorite pair of jeans while rolling the living room walls a beautiful shade of Gray Flannel or Frosty Amethyst. There’s nothing stopping you from painting any of the metals listed above, and in the case of plain old carbon steel, it’s practically required.
And yet, painting stainless steel and other non-ferrous metals is akin to painting a brick house. It’s unnecessary and will almost certainly require additional maintenance as the paint begins to fade, peel, and chip. Yet some people desire the corrosion resistance of stainless and aluminum but without the shiny metallic look. Go ahead, paint it, just be sure to properly prepare the surface first, most likely with some sanding or bead-blasting. A coat or two of etching primer should then be applied, followed by a suitable epoxy and possibly a polyurethane sealer.
A better option might be powder coat. Think of it as dry paint, which it is, although it can also be made of polyurethane or polyester. It requires that the metal being coated is electrically-conductive, which is kind of a dumb thing to say since all metals conduct electricity to one degree or another. Sorry to be so Captain Obvious.
Part preparation is similar to paint in that you need a clean, dry surface or the powder won’t stick. But where paint goes on wet, powder coat is applied electrostatically, using a spray gun that shoots out tiny particles which then adhere to the charged metal surface. It’s that whole positive-negative attraction thing. The coated part must then be placed in an oven to cure for a few minutes, about as long as a quick coffee break. The result is a relatively thick, hard coating that is more durable than that provided by its liquid cousin.
Powder coating is used widely on kitchen appliances, automobile parts, and more. The range of colors available is significantly smaller, however, and it generally costs more than paint. That said, it’s typically a one-coat process (less hassle), can be used to create various surface textures, and is more earth-friendly than paint with its solvents and volatile organic compounds (VOCs). Powder coat is pretty cool.
Whether paint or powder coat, every application is unique. It might be okay busting out the can of Krylon for indoor and non-cosmetic parts, but for those expected to weather the elements (or just look pretty) it’s probably best to speak with a finishing expert before proceeding. SendCutSend is in the quick-turn, online laser cutting business, but we deal with questions like these every day; if we can’t answer your questions, we’ll be more than happy to put you in touch with someone who can.
