Steel is a constantly changing, evolving organic material. Its apparent hardness and strength belies its sensitivity and fragility. It is of the earth. We can paint it and coat it, but it will change anyway; we can only change the time it takes it to change.
When steel rusts inside the structure of a concrete building, causing some of the cement to chip out, we call it a "spalling problem" and, at considerable expense, we hire experts to jackhammer away the cement, get down to the raw steel, coat it with Ospho, re-pack the cement, and re-stucco the building. When bridges have to be repaired, cities shut them down and get grant money or loans. When cars rust, we patch them with fiberglass, grind, sand and repaint. If there was a sure-fire way to prevent rust on all these things, we certainly would be doing it.
There's not.
Rust will develop on all steel. It is inevitable. Beginning with a clear coating, such as a marine lacquer or an automotive coating, will protect steel for a short time, but, unless maintenance is routinely done, even a steel piece with the finest, most expensive coatings, will rust outdoors. One recommended routine maintenance, for indoor or outdoor steel artworks, is to coat the piece with a substance such as Penetrol, which "feeds" the metal, and greatly lengthens the sine curve of the evolution process. For outdoor works, Penetrol can be applied frequently, over the clear finish, maybe even once a month in heavy weather conditions, less frequently if semi-protected, under a roof, though otherwise exposed. For indoor works, Pentrol can be applied perhaps once a year, and more often if the aging process seems to be occurring too fast.
Indoors, steel will still change, no matter what the coating, but it will change much more slowly than outdoors, where change is accelerated, depending on how direct of a hit the steel is receiving from the elements, sun, rain, salt water and extreme heat.
Painting processes are a suitable finish for steel, if a solid color is desired. However, painting will not completely stop rust. Professionally powder-coated pieces, when left outdoors for months, will develop rust. Even one tiny pinhole will admit weather/damage, and rust comes-a-calling. The advantage of painting processes is that the original look can be re-created, provided the same paint/color are used. Near-professional results can be achieved by getting all the rust off the steel humanly possible, using grinders, sanders, sandblasting, etc. Immediately coat the piece with Ospho, trying to get into every nano-crack, letting that dry for at least 24 hours, then painting with an extremely good paint system, such as metal primers and top coats used in the automotive or marine industries. Professional results can be achieved by starting out as above, but after Ospho, coating with a powder-coating system. This can be quite expensive when hired out, but will achieve the longest results. If hiring out a paint job, try to get a small amount for touch-ups from the same batch. Most of these processes result in a glossy finish, but if that is not desired, "flatteners" are available for automotive paints, for example, that will create either a low-gloss or even a matte finish.
Or, learn to love rust, and the evolution process, of steel. Enjoy the changing material as it weathers and ages. Some of the steels I use, for example, have been selected because they were in someone's yard at least 15 years. There's an interesting character to steel that has been deeply pitted with rust, especially very heavy steels: as the material is torched with an oxygen/acetylene mixture, layers of textures and, sometimes, color, are revealed, especially if the material was once painted. Each piece reveals its own unique history and colorations, something like the rings of a tree that tell its story.
Copper & Brass.
Copper and brass behave quite differently from steel. They won't rust!!! However, they will change. That nice, bright shiny copper, when new, will age to a dark dull bronze, just like a brand new shiny penny. Think of the bottoms of copper-clad cookware; if left alone, they get dark. If the original copper color is desired, they have to be scrubbed with paste or powder.
When heated to extreme temperatures (hopefully, prior to melting!), copper can take on a glorious array of colors. The same clear coatings can be applied as mentioned above, for steel, and the material will be protected for some time. I've had copper pieces, coated in clear lacquer, retain their original colorations for more than a year when left outdoors. Indoors, coated copper pieces will hold their original looks for quite some time, for years.
Uncoated copper will gradually age and turn to a green patina. Depending on how much moisture or water hits it, the process can be quick. Many consider this a very handsome color. Vinegar and bleach can also be used to colorize copper. Cat pee creates interesting effects; my cats have done their thing on copper pieces in the yard, and an interesting drizzle-effect of green occurs! If a color other than green is preferred, uncoated copper can be treated with "instant" patina from a bottle. Many colors are available, and these will respond differently, depending on the day they are done, i.e., how much moisture is in the air, how cold or hot the day, etc. When building a piece that is to have a colored patina applied, it is a good idea to create some scraps at the very same time, that have been torched in the identical way. Then, when it is time to apply the patina color, test patches can be applied to the scraps, to be sure it is the color desired.
KATIE TRUAX : : CONTEMPORARY : : 21ST CENTURY : : ANTIQUE : : ARTWORKS
KEY WEST FLORIDA : : 305 296 4186 : : CONTACT