The Power of Metal
More malleable than stone, stronger than glass, and nobler than synthetic materials, metal expresses quality and permanence.
For thousands of years, blacksmiths have fabricated metal works of impressive scale and fluidity. Iron was first forged in the Middle East around 1900 BC and arrived in Europe by 1200 BC. In colonial America, the blacksmith was an essential member of every community. From the creation of ancient weaponry to utilitarian and decorative architectural features, metal work is both art and craft.
Today’s designers and architects have a renewed interest in ancient materials and techniques that express the hand of the maker, and are creating new opportunities for traditional fabricators.
“Part of the charm of the hand-forged metal process is the craft—the artisan’s unique interpretation that expresses an earthy timelessness and tactile quality,” says Michael Reed, principal of Mayer/Reed (Portland, Ore.). “Metal ‘records’ the artisan’s touch and imparts a softness, a warmth, and an organic quality.“
Designer Debbie Cerra of Kahler Slater (Madison, Wis.) agrees. “Nothing compares to the look of metal. It’s the only material that is authentic in look, reflectivity, touch, patina, and aesthetics. It offers durability and a long historical tradition. It’s the real deal.”
The right stuff
Choosing the right metal, finishes, and techniques requires a series of considerations. First, will the project be indoors or out? What conditions will the metal be exposed to? What level of maintenance will be required? What are the relative costs of fabricating one type of metal over another?
“Steel and iron are the easiest to work and less labor intensive since the welds require less finishing than bronze,” explains Chris Connelly, partner/sales manager with De Angelis Iron Works (South Easton, Mass.). The advantages of stainless steel and bronze are their longevity and the fact that they don’t rust, but the higher prices may be a barrier, he adds.
Andrew Barresi of Roll/Barresi (Cambridge, Mass.) selected bronze for the cast bronze plaques at Armory Park in Salem, Mass., because it is not only the most traditional choice, but is long-lasting and requires little care. “One of the most enjoyable things about working with metal is that you are always learning,” says Barresi. “Supervising the casting for this project was a truly collaborative experience involving the long and difficult process of applying a genuine patina to the plaques.”
For signage at the Adkins Arboretum on Delmarva Peninsula, Md., Cloud Gehshan Associates (Philadelphia) had to choose between aluminum and stainless steel. “Aluminum is lighter, easier to fabricate, and cheaper to ship,” says Barbara Schwarzenbach, a CGA associate. “Usually it costs less than stainless, but it isn't as strong as steel, so you have to use thicker material to get the same structural strength and the welds are heavier.” Ultimately, the CGA team chose stainless. “Because it’s stronger, we were able to use a thinner, less expensive sheet material to create an elegant structure with very clean welds,” she explains. “We liked the thinner material, which relates more to the organic nature of the sign design. It took less labor to finish the steel, but in the end the cost to fabricate in aluminum vs. stainless steel was about the same.”
Strength, weight, and electrolytic corrosion are also important factors in metal selection. Electrolysis occurs when dissimilar metals are in contact with moisture, salt air, auto emissions, and industrial pollution that will affect color and accelerate deterioration. “Premature corrosion can be avoided by making sure that the metal has been properly finished to withstand all environments,” says Barresi. “Designers should also be aware of catalytic reaction problems that occur when mixing metals.”
Another factor to consider is how closely the work will be viewed and how people will interact with it. Mayer/Reed’s copper “Quilt” installation for the Underground Railroad Freedom Center in Cincinnati invites touch. “If the work can’t be seen up close and touched, the richness and spontaneity of the surface can’t be appreciated,” says Darryl Nelson, blacksmith at Fire Mountain Forge (Eatonville, Wash.).
Finishes are crucial to the success of a metal installation. Artist and metal sculptor Ray Ciemny of Artisan Iron (Groton, Mass.) works primarily with steel. “Steel can be sealed, waxed, painted, or powdercoated, and there are a variety of coatings available that can even make it look like copper or brass.”
Outdoor pieces must be protected from rusting. For an exterior installation the work is first sandblasted and coated with a zinc-based primer like ZRC, then a latex enamel topcoat is applied. “For powder coating I sandblast and, using an electrostatic gun, spray with a dry powder, then heat and cure to form a ‘skin.’ On interior work I use Valspar Valoil Clear Sealer, which works well on non-ferrous metals, or Renaissance Wax, which will keep the finish stable.” If the work is touchable—like the quilt panels Mayer/Reed designed for the Underground Railroad Freedom Museum—highlights from people’s interaction with the piece can create a rich patina.
At what cost?
It’s difficult to compare the cost of metal to the cost of other materials because every job is different. The price of raw materials, transportation, and fabrication can fluctuate widely.
If metal seems the obvious and most ideal option, Barresi advises working with the fabricator to see how the specs can be modified to reduce costs. Chris Connelly of De Angelis Iron Works agrees. “Every job has a unique combination of labor hours, materials, and installation requirements. We can’t bid on anything without a very detailed set of drawings. In comparing hand forging with other metalworking processes, it is the amount of hand detailing required that affects the total cost. Incorporating other metalwork techniques can also make the job more economical.”
For Debbie Cerra at Kahler Slater, it’s all about quality, “Cost is secondary to the needs of the job.”
Custom forging: finding the best
Locating fabricators experienced in custom forging requires some effort. Although there are many sources of stock architectural metal products, there are not many traditional iron works left. Whether a small one-man shop or a large fabricating facility, all welcome architects and designers to visit and observe the process firsthand.
Connelly advises providing fabricators with detailed drawings and specifications so they can bid as accurately as possible, and Ciemny of Artisan Iron says to pay attention to the questions potential fabricators ask, and look for fabricators who focus on the details. “Not everyone is good at listening. Find a fabricator who understands what you want.”
The relationship between designer and fabricator is a true collaboration. “Our vendors contribute greatly to our ideas and we make a point of working with local fabricators whenever possible. It’s critical to work with fabricators who ‘get it,’” says Cerra.
The challenge for designers is to take a fresh look at traditional metals and techniques and use them in new ways, while respecting the old methods. Only by working with adventurous craftsmen open to exploring different possibilities can this collaborative experience and shared knowledge produce truly exceptional results.
[Sidebar:] Forging ahead: a primer
Although much of the process is ancient, today’s fabricators have made significant improvements to working with metal.
The forge is the furnace used to red-heat metal. Originally wood-fired, forges are now typically fueled by coal, coke, or propane gas, which is clean and non-polluting, although not as hot. During the heating process, metals become malleable and can be pressed or hammered into the desired form. Metal artisans use sledges or hammers to beat the work on a metal anvil.
The difference between hand forging and machine forging is in the use of machine-powered hammers or presses that strike heavy, rapid blows, improving the structure of the material and making it more impact resistant. Because machine forging is faster than hand labor, fabricators often use a combination of both methods. The forging process refines the grain size of the metal and makes it stronger than cast metal.
Other metalworking techniques include:
- Casting, the method by which liquid metal is poured into a mold. Metal can also be cast to replicate the look of forged.
- Drop-forging, the placing of soft, hot metal between two shaping dies. The upper die is hammered, or “dropped” onto the lower one, forcing the hot metal into the shaped depressions (as in coin making).
- Hot rolling, which involves manipulating a sheet of metal between rollers to form a material shape.
- Waterjet cutting, which uses highly pressurized waterjets to cut metals and other materials, including stainless steel, granite, titanium, and ceramic.
- Laser cutting, a gas-powered method that employs an intense light beam as the energy source and is highly efficient in cutting all types of metal, plastics, glass, and wood.
On an environmental note, in all metalworking processes there is no waste. Scrap metal is collected from the fabricators and recycled; nothing ends up in a landfill.
--By Linda Cooper Bowen, segdDESIGN No. 24, 2009