Found art

Welding artist finds inspiration in industrial, natural forms

Practical Welding Today May/June 2003
June 12, 2003
By: Kathleen McLaughlin

Watching the sparks fly as his dad welded a temperamental posthole digger mesmerized Derek Arnold. "I found the immediacy of something so permanent absolutely fascinating," he said. "I knew I wanted to weld."A hands-on welding education on the family farm drove Arnold to take his skills and creativity to the next level. In 1993 he graduated from the Maryland Institute College of Art in Baltimore. "I've been welding regularly since my freshman sculpture class," he said.

Arnold's first job out of college was with the New Arts Foundry fabricating bronze statues. However, he quickly grew tired of following someone else's blueprints. A year later he landed a commission to design and fabricate 150 feet of ornamental iron railing for a private residence. After the project was completed, Arnold's creativity and love of welding pushed him to open his own design and fabrication studio.

Prehistoric Junkyard Art

Heavy-equipment graveyards are the muse that incites Arnold's infatuation with designing and welding. "I like working with discarded steel because it gives a glimpse of the past and reminds us how important industry and technology are in our lives," he said. "I explore avenues to integrate different materials in such a way that the character of each is evident, so the combination has unique meaning and personality."

He was able to push the bounds of his creative abilities after winning a commission from Johns Hopkins University's Evergreen House for an outdoor sculpture in 2000. "I'd had my eye on a 1946 Caterpillar scraper, and before the commission I didn't have a reason to take it home," he said. "I like reusing old parts, like pins and hinges, that have a history and still work structurally."

Visions of a "Cateraptasaurus" (see Figure 1), a part machine and part creature sculpture, began forming in Arnold's mind. His next challenge was cutting up the old machine. "I have to calculate where to make cuts to create the most out-of-the-ordinary shape," he said. "I have hundreds of pieces, and it becomes a game of concentration—remembering where all these pieces are and visualizing them fitting together. I try to make the parts look as if they were made to be in my creatures. Sometimes I have to trim the material or add a piece to round out the form."

Figure 1
"Cateraptasaurus" weighs more than 12,000 lbs. and is made from a 1946 Caterpillar scraper, a backhoe, and other Caterpillar tractor parts donated by the Alban Tractor Company, Baltimore.

To make his vision a reality, Arnold teamed up with the Alban Tractor Company, Baltimore, to supply extra parts. "The sculpture is almost all Cat® tractor parts, but I couldn't get everything I needed off of the scraper," he said. "Sometimes things don't go together right. I'll plan it one way but it doesn't work, so I have to abandon that piece of metal and try another."

The curved chest of the creature is the neck of the scraper, and the tail is part of the draw bar. "I cut apart front end loader buckets to make the teeth on the creature's spine." The sculpture weighs more than 12,000 pounds and balances on two feet. The two feet are 12 ft. across from outer toe to outer toe and 6 ft. from front to back.

To join the sculpture's hundreds of pieces, Arnold used shielded metal arc welding (SMAW) with 1/16-inch-diameter, flux-core arc welding (FCAW) wire with a suitcase-type welding machine (see Figure 2).

Figure 2
To join the sculpture's hundreds of pieces, Arnold used SMAW with 1/16-inch-diameter, flux-core wire with a suitcase-type welding machine.

"I chose the MIG process because it's faster, and I could lay more metal without stopping to change rods," he said. "I also used stick welding and went through about 500 lbs. of 7018 electrode. I felt comfortable with stick welding because some of the metals were painted and somewhat dissimilar, and with this process I felt I could join these metals together. I overkilled everything and put a lot of weld on it."

Arnold enjoys blurring the lines between organic and mechanical forms. "From a distance, the sculpture's form resembles a dinosaur, but the closer you get you start to see all the mechanical connections," he said. "It almost looks like the creature could walk if it was hooked up with hydraulics to become a functional machine to lift rocks."

Kinetic Art

Arnold doesn't believe in throwing anything away, and during production of "Cateraptasaurus," a patron approached him to design a metal and stone sculpture (see Figure 3). "I began designing this piece thinking of a visual layout for the seven flagstones and designed the steel around them," he said. "To make it spin, I needed vertical columns, which coincidentally were left over from 'Cateraptasaurus.' It was serendipity!"

Figure 3
The 3,000-lb. stone and steel kinetic sculpture is 15 ft. tall and is bolted to 8 tons of concrete.

At inception of the piece, Arnold knew he had to figure out how to balance 3,000 lbs. of kinetic sculpture. "Because it's spinning, every degree of rotation has to be perfectly balanced," he said. Arnold created a spreadsheet in Microsoft Excel and calculated three different degrees of rotation, such as 0, 90, and 270 degrees. He then entered all pertinent information about each piece of material.

"Using the spreadsheet made it easy to change the material's thickness before welding the steel. This helped define the exact weight of the sculpture's left side and right side for all three calculated angles," he said.

To join this mathematical kinetic puzzle, Arnold used a combination of SMAW and GMAW. "I designed the piece in CAD and MIG welded the pieces together," he said. He chose SMAW to weld the base plate to the vertical columns. "I had to skip around to make sure the plate didn't warp or bend."

The sculpture is motion-driven by a motor and gear reduction to achieve a range of speeds. The entire piece is 15 ft. tall and is bolted to 8 tons of concrete. "It's a combination of organic and mechanical imagery with a randomness of how tree branches grow," he said.

Future Horizons

True to his restless nature, Arnold currently is designing a ship—a 32-ft.-tall, freestanding outdoor sculpture—for the Baltimore City Public School System.

"It will be constructed with modern-day technologies," he said. "I will design it in CAD, and the parts will be plasma- or torch-cut by a steel supplier. I'll use MIG and stick welding to join some recycled metals."

Whenever Arnold takes on a project, he admits to being slightly intimidated by a new design. "Working with the unknown is a challenge," he said. "When I start a project, I'm not always sure what it's going to be exactly. I also have a habit of taking on projects that I've never done before, or I'll have no idea how I'm going to do something."

Regardless, the idea of taking a piece of metal and fusing it with another piece of metal continues to fuel Arnold's passion for welding and creating sculptures.

To find out more about Derek Arnold's work, contact him at P.O. Box 12, Jarrettsville, MD 21084, 410-692-9662,,

Kathleen McLaughlin

Kathleen McLaughlin

Contributing Writer

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