Vol. 38, No. 18

1-17-2007
By: Richard Gillette

Third-generation glass blower

When someone tells Tim Henthorne he’s full of hot air, they’re not far from the truth. Henthorne, a senior scientific glassblower, uses a lot of hot air to create just about any glass apparatus found in campus research labs.

And for more than 80 years, three generations of Henthorne’s family have created the glasswork in the university’s glassblowing lab, located in the basement of Evans Laboratory. His grandfather, William Leonard, started the lab circa 1920.

Henthorne was taught his glassblowing skills by his father, William Henthorne, but if it were not for his mother he probably wouldn’t have learned the trade. On Henthorne’s parents’ first date, his father was introduced to Leonard, who at the time was working on a glass project in the basement of his Columbus home.

“The story I’ve been told is that he was so enthralled by what my grandfather was doing that he didn’t take my mother on the date and stayed to watch my grandfather’s work. That’s where he got his start,” Henthorne said with a chuckle.

Like many children who follow in their parents’ footsteps, Henthorne had no plans on becoming a glassblower. He started out at Bowling Green and later transferred to Ohio State, where he graduated in 1988 with a degree in photography and cinema.

He wanted to be a photographer, but during his undergraduate years Henthorne’s father landed him a job as a secretary in the glass lab. He observed his dad spend endless hours producing and repairing rotary evaporator condensers and various other glass items.

“A few times someone came in to get something repaired and my dad wouldn’t be here, so I started making the repairs. After watching him for so many years, I was able to catch on and do the work,” said Henthorne, who eventually fell in love with the profession.

Since 1989, Henthorne, the youngest of four siblings, has carried on his family’s glassblowing tradition at Ohio State. His father, now 82, retired after more than 40 years of service at the university. Even in his 70s, William Henthorne came back to help his son when there was a backlog of work.

The glassblowing lab offers repair, modification and custom design of scientific borosilicate (Pyrex) or quartz glass apparatus. Henthorne’s work ranges from simple glass tubes to large, complex fermentation coils. If you can describe it, he can build it.

Some projects take a few minutes, others take weeks or even longer. He spent a month on a 17-foot long glass microwave chamber built for Homeland Security research in the Department of Physics. But Henthorne’s biggest challenge isn’t the time it takes to create the glasswork, it’s the delivery.

“One of the hardest parts of my job is making sure a department receives the glass in one piece. A bump here or a wrong turn there and you have to start over. You can take hours to create something complicated, but if you can’t deliver it in one piece it’s not worth anything,” he quipped.

Although not educated in the sciences, Henthorne is proud of the devices he has formed that have contributed to scientific research.

He’s created chambers employed in open-heart surgery research and shaped complicated pieces for mosquito feeder testing. University research labs have also widely used his intricate glass vacuum systems.

Members of the Department of Chemistry, where more than 50 percent of his work comes from, praise Henthorne’s glassblowing skills.

“Tim is very knowledgeable about his craft. You can go to him with something and really not know what you need and he will help you work it out,” said Professor Sheldon Shore, who should know good glassblowing work. He’s worked with all three of Henthorne’s family members during his 50-year career at the university.

The workload has slowed recently, but Henthorne, who works alone in the glass shop that at one time had four employees, believes a glassblower will always be needed. By doing the work, he can save departments 75 percent of their replacement costs.

Will another Henthorne replace him in the glass shop? His job description now contains a goal to have him train someone before he retires, but he doesn’t expect his junior high daughter to take over.

“She has other interests and I don’t plan on pushing her into the work,” he said.

Not all glassblowing created equal

Scientific glassblowing involves patience and an artistic touch. But the work should not be confused with offhand glassblowing or artistic glassblowing, said Tim Henthorne, senior scientific glassblower.

Offhand is the more traditional type that people associate with glassblowing. Instead of using preformed glass rods or tubes like those used in scientific glassblowing, the offhand technique uses a molten glob that has never been formed.

Offhand glassblowing uses three heat sources — a furnace, glory hole and an annealer (a place to heat and then cool the glass) — to create more artistic pieces that require a lot of handwork by several people. Henthorne has never created glass forms using the offhand technique.

“I wanted to save something for when I retire. If I do it all now, there won’t be anything left to explore,” he said.

Scientific glassblowing requires a torch or burner to melt glass or quartz and a blowtube to help control the shape of the finished work. A furnace is used to anneal the glass. The annealing kiln in the lab achieves a temperature of 1,170 degrees Celsius (2,138° F) and requires as much electrical service as the typical residential home.

Although machines like a lathe are sometimes used to help form or construct complex glassware in scientific glassblowing, Henthorne thanks his father for teaching him hand techniques.

“I was fortunate he taught me how to do many operations freehand. It pays off when something comes in and you can’t use a machine on it,” he said.

Henthorne was awarded the Andrews Glass Award for best technical paper at the 1999 American Scientific Glassblowers Symposium. For more information, visit chemistry.osu.edu/shop_statements/glass/glass_shop.

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