Professional Jeweler Archive: Lee Marshall, Mechanical Wizard

November 2000

Precious Metals & Bench/Metalsmithing

Innovators 9:
Lee Marshall, Mechanical Wizard

Enterprising engineer brings high-tech manufacturing to low-tech jewelry workshops

He could rightly be called the “Mr. Wizard of Jewelry.” But unlike the TV personality, Lee Marshall comes up with inventions that aren’t just curiosities; they are real time- and energy-savers that expand the horizons of hundreds of jewelers each year. Lee’s creations, – the Bonny Doon Press and accessories – have changed the way some of today’s most creative jewelers and designers work. Here’s how he did it.

Mr. Fix-It

A self-educated engineer, Marshall has designed and made machines throughout his life. He’s particularly interested in creating things that can’t be bought from a catalog. “Growing up on a farm, if something broke, you tried to fix it so it wouldn’t break again,” he says. “Since engineering is nothing more than the study of failures, you learn pretty quickly about the strength and proper use of materials.”

Marshall left college after one semester because he couldn’t see its relevance. “In the ’50s, the main thrust of universities was to create space engineers so we could compete with Russians. Their approach was to cram 18 units of academic classes down your throat each term and, in four years, shove you out the door with a diploma and a dazed look on your face as you saw daylight for the first time.”

Marshall worked for various companies, creatively solving successively more complex mechanical problems. He eventually became vice president of engineering for a company where he and his research-and-development department were exposed to extremely toxic fumes from a supposedly innocuous material. It severely impaired his short-term memory. “I would get lost just driving home!” he recalls. The company refused to accept responsibility for the accident and terminated his employment.

Unemployed and unemployable, Marshall was demoralized. He saw little prospect of ever working again. Over the next few years, however, his condition did improve and eventually he recovered.
Learning Jewelry Making

During his rehabilitation, Marshall took a jewelry class with Linda Watson at his local community college. He picked up the basics quickly. Adding this to his love of machinery, Marshall embarked on a journey through jewelry and became one of the industry’s best-kept secrets. He also attended San Francisco’s Revere Academy of Jewelry Arts, where he received one of the school’s first graduate diplomas.

Eventually, he met Susan Kingsley, a jeweler/metal sculptor in California who used a homemade press to form the metal components of her work long before others knew the technique. Susan’s press touched off Marshall’s imagination. He knew better and easier ways to work, so he set out to make an improved press for Kingsley. He added tools and made improvements to things she hadn’t even realized needed improving.

Ten years ago, at Kingsley’s suggestion, Marshall built a few presses and exhibited them at the annual Society of North American Goldsmiths conference in San Francisco, 85 miles away. He sold out at the conference and took orders for more.

In the blink of an eye, Bonny Doon Engineering was born, at first offering only one type of press and a few accessories. But word spread quickly about the press and the possibilities it offered. His first catalog was a single photocopied sheet of paper; the current Bonny Doon catalog contains 20 pages filled with tools and equipment for small- to medium- scale manufacturing jewelers.

Why Marshall’s Work Matters

Marshall brought high-tech manufacturing into low- tech jewelry workshops. He translated the language of mechanical pres sing, forming and blanking across industries.

In a nutshell, the Bonny Doon system is composed of a welded box frame with a hydraulic jack mounted on the inside. For forming, a sheet of metal is sandwiched between an object and some urethane (a rubber-like material). As the pressure is increased, the metal is forced into and around the shape of the object. Add tool holders and special dies, and the metal can be fashioned free-form in ways not possible with traditional techniques.

The press enables you to form an object with greater precision and in a fraction of the time used in traditional forming with hammers and stakes. It also offers the potential of re-creating the same object countless times with the same hyperspeed as the original.

The Bonny Doon press is now used by some of the most prominent contemporary jewelry makers – including Kingsley, Betty Helen Longhi and Phil Poirier – as well as many jewelry manufacturers who might not be seen as artists. For information about the process, techniques, tips, tools, suggestions and a gallery of work made with the press, check out Bonny Doon’s Web site (

– by Alan Revere

Alan Revere is a master goldsmith, award-winning jewelry designer and founder of the Revere Academy of Jewelry Arts in San Francisco, CA.

Copyright © 2001 by Bond Communications