When Bonnie Rubinstein talks about fusing glass, she often sounds like a scientist — which isn’t surprising, because when she isn’t fusing glass, she is a scientist.

“There’s a lot of science in this,” she said, launching into an explanation about the importance of factoring in the coefficient of expansion when picking pieces of glass to fuse. When she noticed a visitor’s eyes glazing over, she quickly segued into a dumbed-down version.

“The glass has to be compatible,” she said. “You can’t fuse the glass from a beer bottle with the glass from a wine bottle because their molecular structures won’t work together.”

Sometimes layering pieces of glass and other times aligning them side by side — and occasionally adding crushed glass to the mix — Rubinstein heats glass to temperatures approaching 2,000 degrees and monitors it carefully as it melts just enough for the pieces to run together and bond. The resulting designs — which range from serving bowls to 20-foot wall sculptures — are so cutting-edge that the late fashion designer Bill Blass, whom she met at a Symphony Ball, took a look at her work and told Rubinstein that she should leave the stodgy Upper Midwest for the hip East Coast.

Rubinstein, who came to the Twin Cities in 1980, declined. “I grew up in New York City. I left there because I didn’t want to stay there.”

These days she splits her time between her studio in a converted barn near River Falls, Wis., and an office in St. Louis Park. She also splits it between creating art and running EcoSource, an environmental consulting company that works with several of the state’s largest corporations.

Rubinstein always has vacillated between careers. She started as an urban planner and then became a designer of high-end fashion jewelry, a business that she abandoned during her first pregnancy when she was told that she should avoid the adhesives she was using. She launched EcoSource in 1990, but she could never completely escape the tug of artistry.

“I needed to use my hands more,” she said. “I needed to create something.”

She was fascinated by the aesthetic potential of glass. “I don’t think there’s any medium quite like glass,” she said. “When color and light work together with glass, it’s alive.”

She struggled to find the right discipline, though.

“I tried glass blowing, working with stained glass and making neon lights,” she said. “Nothing signaled me that this is what I should be doing.”

Then she stumbled on fused glass. “I realized that I could create art in glass,” she said. “If you blow glass, you can make beautiful things, but you can’t compose an artpiece. Because I create in cold glass, I can create art that stays intact as I fuse it.”

Learning on the job

Fusing glass is a relatively new art form, having been around only a couple of decades, something Rubinstein discovered when she went looking for a mentor and couldn’t find one.

“I had to learn this myself because there was nobody to teach me,” she said. “I started playing around with glass and bought a kiln [for the fusing] without knowing much about what I was doing. I had a lot of surprises before I came to understand how it all works.”

Fusing glass involves multiple variables, starting with the temperature in the kiln, but also how quickly it is heated up to that temperature and how slowly the glass cools afterward. The entire process can take up to 20 hours. Rubinstein has a notebook full of the schedules she has used, noting what happened at which temperature over what time span.

“Scheduling the kiln is crucial,” she said. “If I didn’t keep good notes, I couldn’t do this.”

Peeking into a 2,000-degree kiln to keep track of how things are going poses challenges of its own, she has discovered. “I’ve melted several flashlights,” she said.

In addition to her kilns — she now has three: small, medium and large — she also has accumulated an array of other equipment, including a sandblasting cabinet for etching the glass and diamond-tipped drills and saws for cutting it.

“I get more excited about shop tools than about clothes,” she said, adding excitedly: “You should see my air compressor!”

Shall we dance?

She compared her creative process to a choreographer creating a dance.

“The glass talks to me,” Rubinstein said. “The dance happens between my vision and the art’s own identity. The medium becomes the muse. There’s always something new and wonderful you can do.”

Her experience in urban planning informs her wall sculptures, she said.

“My background gives me a sense of what enhances the identity of the space,” she said. “Whenever a client calls to commission a work, I like to go see the space.”

She also personally oversees the installation of the finished pieces. Using lights to accentuate the color schemes in the glass, she prefers to camouflage the mounting hardware “so they look like they’re floating in air.”

With vibrant colors and upbeat themes, her artwork has found a particularly appreciative audience in hospitals. In fact, her gallery’s website (www.rubinsteinstudio.com) includes a page devoted strictly to hospital commissions. Locally, she has made pieces for the Children’s Hospitals in both Minneapolis and St. Paul as well as Abbott Northwestern Hospital.

Her designs “perfectly represent Children’s with kids in bright colors celebrating dance, music and culture,” said Theresa Pesch, president of the Children’s Foundation at Children’s Hospitals and Clinics of Minnesota. “We’re thrilled to have donor support from community members to display art, and I love seeing how beautiful pieces, such as Bonnie’s, bring a smile to patient and family faces while in our hospitals.”

Rubinstein feels as if she is still learning on the job.

“Working with glass is a very humbling experience — daily,” she said. “Cutting the shapes, choosing the right colors to fuse together without looking muddy, programming the kiln so the hot glass is annealed correctly and does not suffer from thermal shock, and engineering the anchoring of the art to the walls, ceiling, countertops, etc., all requires art and science expertise.”

Her biggest frustration is that fused glass is still largely unknown as an art form.

“I spend a lot of time educating people,” she said. “They look at a piece and say, ‘How did you blow that?’ I have to explain that I didn’t.”

Although her work is on display on her website and in her studio, getting galleries to show it has proved difficult. “They don’t know what to do with it,” she said.

None of which is going to force her to give up.

“I believe in this medium a lot,” she said. “It’s unique. I just have to let other people know it exists.”