PPP: Fired Up

Installing an industrial kiln has helped Edgecomb Potters revolutionize its production process.

Vases with a crystalline lime glaze.
The year was 1976. America celebrated its bicentennial, Rocky Balboa took Apollo Creed the distance, and a Bostonian named Richard Hilton faced a difficult decision: take a pay cut in his job as a radio announcer or start a new career in ceramics. Until that point, pottery had been a side gig, something Hilton had picked up from his wife, a former high school instructor, and enjoyed. He'd had a certain degree of success selling pieces at fairs and in galleries, but could he really make a living turning clay? The Hiltons would find out. In the summer of '76, they traded Boston for a one-room schoolhouse-turned-studio in Maine and rolled the dice.

Thirty years and five Rocky films later, the gamble has definitely paid off. Richard and Chris Hilton's Edgecomb Potters-Maine's largest pottery company-now boasts 100,000 sq. ft. of production space on its main campus in Edgecomb. Sixty-five percent of the company's business comes through its retail outlets in Edgecomb, Freeport and Portland, and Edgecomb pieces are sold in an additional 60 galleries across the country. It might be an understatement to say things are going very well for the Hiltons now, but it wasn't long ago that a major element of Edgecomb's production process needed an adjustment.

A scalloped platter with a crystalline blue glaze. Photos courtesy of Edgecomb Potters.

Burning Out

When the Hiltons first started out, Richard built the kilns they used to fire their pottery. A caternary-arch kiln came first, followed by a shuttle kiln and a handful of others. The company made the move to more commercial electric kilns once they started using crystalline glazes on their pieces, but Richard-a trained chemist-was less than impressed with the kilns' performance.

"With crystalline glazes, kilns have to hold at an exact temperature for a certain amount of time to allow the crystals to grow," Richard explains. "The heating elements in the electric kilns sat in a groove of brick, so we weren't getting full efficiency."

Richard found that the elevated temperatures needed for his crystalline glazes caused the elements in his electric kilns to burn out with surprising regularity. While elements could always be replaced, the process was extremely difficult and could only be repeated a few times. "By the third time we changed the elements, the kiln's shell had about had it because the brick started to break," Richard says.

Frustrated as he was with his "throwaway" electric kilns, Richard found few alternatives on the market for his firing purposes. Though a solution would eventually present itself, it would take 10 years, a tax break and a certain degree of German ingenuity to put things straight.

A smaller version of the shuttle kiln installed in Edgecomb's facility.

The "Rolls Royce" of Kilns

The first time Richard saw a Nabertherm kiln on display at a solar-panel manufacturing plant in Worcester, Mass., in 1995, he knew he had to have it. Though the larger models had only ever been used for industrial ceramic purposes, they were durable and more than capable of meeting his firing needs with their free-radiating, rod-supported elements and computerized controls. "I was salivating," Richard says of his discovery. The only downside? The price tag.

For all the kiln's usefulness, Richard knew he couldn't justify the $80,000-plus total cost of what he describes as the "Rolls Royce" of kilns. Edgecomb's electric kilns may have had short life spans, but they weren't that expensive. Even so, Richard did his homework. He gathered information on the Lilienthal, Germany-based Nabertherm GmbH and its products and waited.

Early in 2003, Richard learned of an amendment to Section 179 of the Federal Tax Code that would allow a small business like his to write off $100,000 of the cost of new equipment in the year of its purchase; the balance could be written off the following year.* Richard immediately set up a meeting with representatives of Nabertherm's U.S. office to discuss purchase options; within a matter of months, the deal was done and the kiln was in place at Edgecomb.

Of course, getting the unit to suit his particular application was another story.

*This deduction is applicable to the 2003, 2004 and 2005 tax years. For more details, see http://www.selfemployedweb.com/section-179.htm and/or consult a qualified accountant or tax advisor.

Mounting heating elements in grooves (a) is a common practice in

pottery kilns. However, this practice can trap heat from the elements, shortening their life span. When elements are removed from the grooves for maintenance, they can damage the lining. Edgecomb's heating elements are mounted on ceramic support rod


According to Richard, the shuttle kiln** that arrived at Edgecomb in December 2003 was a thing of beauty. Not only did it offer 77 cubic feet of firing space, but its ergonomic design-complete with an easy-rolling kiln car and easy-to-open door-eliminated the strain of bending and lifting that's common with smaller electric kilns. But firing crystalline glazes was uncharted territory for the big machine. Both Richard and Nabertherm knew from the outset that some adjustments would need to be made.

The first issue to be addressed concerned the kiln's temperature distribution. Richard soon realized that pieces placed at the top of the kiln were not receiving the same level of sustained heat as those at the bottom. Nabertherm sent technicians to Edgecomb to profile the temperature distribution in the kiln and optimize the kiln's computer program. It soon became apparent that the kiln's single control zone did not provide the accuracy needed to meet Edgecomb's firing needs. Nabertherm divided the heating system to give the kiln four independently controlled zones, thus maintaining a constant temperature-and ensuring high-quality end products-throughout the unit.

(b). All the surfaces of the element radiate heat freely, so the elements last longer. When an element needs to be replaced, the rod is removed from the brick support, and the element is slid off the rod without damaging the kiln lining.
A second problem developed shortly thereafter-the bricks that held the element rods in place began cracking. Nabertherm quickly dispatched a team to remediate the problem, throwing in a complete set of future element replacements for the inconvenience.

Rod holders and uneven temperatures weren't the only hurdles Richard faced during this time, however. Because the new kiln required more power than any piece of equipment the company had ever used, Edgecomb had to arrange for a $15,000 electricity upgrade through its local power company, which then necessitated the purchase of a $20,000 phase converter that would allow the motors on the company's previously existing units to continue to function. When all was said and done, about seven months of troubleshooting had passed. Winter had turned to spring and then summer, and Edgecomb Potters was ready to fire some clay.

**Nabertherm model W 2200/H

The new kiln has allowed Edgecomb Potters to increase firing efficiency and significantly reduce maintenance headaches.

Worth the Wait

With its glitches finally worked out, the kiln has worked like a dream for Edgecomb Potters, says Richard. The company averages $20,000 (retail) in product per 22-hour firing cycle, so the kiln has already paid for itself. Additionally, Richard reports that the kiln's elements-now on their 60th firing-look as though they'll give him at least 90 more. All of this is good news for a business whose retail units will see up to 200,000 shoppers this summer.

"It really is incredible," Richard says. "Nothing's like the Nabertherm."

For more information about Edgecomb Potters, visit http://www.edgecombpotters.com.

For more information about the shuttle kiln described in this article, contact Nabertherm Inc. at 54 Read's Way, New Castle, DE 19720; (302) 322-3665; fax (302) 322-3215; e-mail contact@nabertherm-usa.com; or visit http://www.nabertherm.de.

Editor's note: Kiln selection is a function of many different variables. While electric kilns did not suit the specific needs of this application, they are the best option for some pottery producers. This article is not intended to recommend the use of one kiln type or brand over another but is merely a case study of one pottery producer's experience. Pottery producers should carefully evaluate all options before choosing a particular piece of equipment.

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