Metal as an Artistic Medium
There are several types of metals the metal artist needs to concern themselves with. Bronze, a copper and tin alloy know since ancient times. It has been utilized for statues and sculptures due to its permanence and the variety of attractive patinas that form when exposed to the elements. It was not until after the start of the 20th century that steel entered the realm of fine art. This metal was later joined by stainless steel and aluminum. Stainless steel and aluminum are products of the industrial revolution that require sophisticated methods for isolation and formulation
Steel is a widely available and widely distributed structural metal. This metal has been key to the development of the Industrial Revolution.It is used in automobiles and construction of buildings and skyscrapers.
Steel is a hard yet malliable metal that can be worked in various ways. It can be milled, drilled, cut, hammer forged, welded, brazed, and soldered. It is used for representative sculpture as well as abstract and conceptual metal art. It can be heat colored, artificially rusted, power coated, and painted when a suitable primer is used.
There are two main types of mild steel commericially available to the artist. The types are cold rolled and hot rolled steel. The biggest visual cue is the mill scale on hot rolled steel. That is because hot rolled is shaped and rolled in a condition of high temperature. Also, the edges of the steel is rounded and mesaurements are not exact. Hot rolled steel machines easily due to the heat treatment.
Welding of Metals for Sculpture
Considering the different materials available to artist, it would be a good idea to mention a process of joining metals together. One way to do this is by welding. Welding is, by definition, joining two similar or dissimilar metals with a molten filler metal. There are two main ways to accomplish this task.
One way is to actually bring the joining metals to there melting point with an addition of a filler metal of the same type. This by far will form the strongest bond. Most of the electric arc welding processes such as TIG, MIG, and Stick operate on this principle. Less common but still applicable in the arts is fusion welding with an oxyacetylene torch. Possible disadvantages might be extensive warping of substrate by the great heat of the process.
Another process would be braze welding process. This essentially employs a filler metal at a lower melting point than the joining metal yet higher melting than solder. This process has the benefits of reduced warping due to lower temperatures(1100°F to 1700°F). Another advantage is the filler metal often “wicks” into the joint via capillary action. This eliminates the unsightly weld beads without sacrificing too much strength. This would be idea for painting. Also, it is possible to join different metals and alloys together so long that the different metals are compatible with the filler metal and can stand the heat of the process. Most of the time an oxyacetylene torch is used for the process.
As you can see there are many considerations on just joining metals by welding of these various materials. A comprehensive description of each process is outside the scope of this article. Hopefully the table above will give the budding artist at least a rough idea of what process to approach to begin
Copper has been known for thousands of years and it was probably one of the first metals worked by man. The properties that define copper metal are its excellent electrical conductivity, its malleability, and numerous finishing possibilities. Copper also has red brown sheen. In modern times it is a staple in electrical cables and wires and as a conductor on printed circuit boards. In more creative circles, it is used for making copper garden sculptures, cups, bowls, and water fountains.
Copper is easily formed and bent but gets harder with continuing shaping, hammering or folding. It needs to be heated to red heat to anneal and soften the metal so it can be worked without danger of it cracking or breaking under stress.
Copper is available in sheet, plate, bar and wire. It is sold by roofing contractors, home improvement stores, and metal supply houses both brick and morter and online.
Bronze is a metal that has all the aesthetic qualities of copper but is almost as strong as steel! And to add to that bronzes have an even higher resistance to corrosion than copper. This is why bronze has many industrial applications in food handling and marine environments. For artistic purposes it is usually best to exploit the casting of bronze. Bronze lends itself well to taking on intricate details well in casting and you are limited only to your imagination and creativity. Also, bronze has the property to form beautiful patinas. The equipment is easily built at a modest cost but the casting alloy can be pricey as it is at least 3 times the cost of pure copper!
Stainless steel is a very special alloy of steel. This alloy incorporates nickel and chromium with the steel to impart remarkable strength and corrosion resistance. It is used extensively in commercial kitchens,hospitals, and in chemical manufacturing. This is due to its ability to resist rusting and maintain a smooth shiny surface.
Stainless steel offers sophistication to the skilled metal artist. It is much stiffer and harder to work than ordinary steel. For drilling, fresh sharp bits are a must because staineless steel work hardens the longer you take with a drill bit. For bending sheet it is recommended that you score the sheet with a metal cutting wheel mounted on an angle grinder. Stainless can be brazed but does require a little more flux. There are also special stick welding rods and MIG welding wire available for electrically welding stainless steel.
Aluminum is a late addition to the artistic metals. Aluminum was first isolated at the peak of the Industrial Revolution back in the late 19th century. It is was made by running a high current DC power source through a molten mixture of bauxite mineral and cryolite. The cryolite acts as a low temperature flux to fluidize the bauxite aluminum oxide which has melting point of 2000 Celsius! With cryolite as the flux and electrolyte, the aluminum isolation can be conducted at a much more manageable temperature of 1000 degrees Celsius.
Aluminum as a pure metal has little industrial use much like iron. It is a soft metal with little strength. Aluminum does form some very useful alloys though. Not only are they harder and stronger but they resist corrosion by forming a protective oxide coating. Not to mention that aluminum is nearly 3 times lighter than steel. This makes aluminum very popular in aviation and automotive industries.
Aluminum was slow to be accepted as an artistic material. It is seen by some as being cold and indifferent. Aluminum is relatively easy to cut and drill but difficult to weld. Sophisticated TIG or MIG arc welding equipment is needed and this can be a financial barrier to many artists and crafty people. Although it is considerably easier to braze and solder aluminum with relatively simple gear.