Thursday 5 April 2018 9:55pm
Scientific glassblowers Greg Kerr and Anne Ryan, of the University’s Glassblowing Unit, estimate they produce upwards of 1,500 custom-made and small sets of scientific glassware each year. Photos: Sharron Bennett (unless otherwise specified).
Otago On Location (a feature series shared from Otago Connection), takes a look behind the scenes of some of the University’s most stunning, unique, historic and amazing spaces. In this instalment, we visit the Glassblowing Unit – an on-campus workshop for the manufacture of scientific glassware and a retail store of standard laboratory glassware.
The University hasn’t always had its own glassblowing facilities, says Ms Anne Ryan, an accomplished scientific glassblower who has managed the Unit since the early 90s.
“Ted Facer arrived from the Biochemistry Department at Oxford University in 1954 to establish the Glassblowing Unit within the University of Otago Medical School. He joined a workforce of four glassblowers in New Zealand universities.
“Glassblowers at the time were closely involved with specific research projects and while academic staff had some hands-on glassblowing skills, a specialist glassblower was desired to progress research and teaching.”
Brooker funnels, named after Professor Sally Brooker, the Otago academic who commissioned them.
The glassblowing workshop was originally located in the basement of the Lindo Ferguson building.
When the School of Pharmacy vacated the Zoology Annex in mid-1980, the space was renovated to house the Glassblowing Unit and retail store. The space has roughly halved since that time with Zoology laboratory and offices moving in.
Sections for a heart model.
Soon after the initial Glassblowing Unit was established, workshops were subsequently developed in the Department of Physics and Department of Chemistry.
While the Physics workshop is now closed, Mr John Wells continues as the glassblower dedicated to work within the Department of Chemistry.
A commercial scientific glassblowing and glass importing business in Dunedin also has ties to the University Glassblowing Unit; it is run by Mr John Penno who was trained within and in charge of the Unit in the mid-70s- and 80s.
There is a long history of trainees at Otago’s Glassblowing Unit. Ms Ryan got her start in glassblowing when a trainee position was advertised requiring a science background and manual dexterity. With “two boxes ticked” she began a five-year apprenticeship in 1980 following Ted Facer’s retirement. Part-time glassblower Greg Kerr began his training a few years later.
In 2016, the Unit was commissioned to produce a community science lifetime achievement award which was presented at that year’s New Zealand International Sciences Festival. Photo: Ken Miller, Department of Zoology.
The glass used in scientific laboratories is not the same as the glass you drink your favourite chardonnay from.
Borosilicate glass – used in the scientific laboratory equipment – and soda/lime or 'soft' glass – used in bottles, jars and window glass – are both mainly composed of silicon dioxide. However, the higher percentage of silica and boron oxides in borosilicate glass, and sodium and calcium oxides in soda glass, means the temperature at which each material achieves a molten state differs.
Soda glass has a lower molten state temperature and is therefore cheaper to produce. However, it is more prone to expansion and contraction when heated and cooled making it less suitable as a material for scientific laboratory applications.
According to Ms Ryan, the predominance of borosilicate glass in the scientific laboratory comes down to its relative chemical inertness, transparency, resistance to thermal shock and its potential to be formed into complex structures, repaired and modified.
From a glassblower's perspective it is more forgiving.
“In practice this means more emphatic heating and less angst about cracking,” she says.
Borosilicate glass has a working temperature of 1260 degrees Celsius. At this temperature, the viscosity of the glass is such that it begins to flow and behaves like a fluid, responding to gravity.
The glassblowers’ equipment uses LPG, and pressurised industrial oxygen is added to achieve the necessary high temperatures. Specialised glassworking lamps are used, the choice of which depends on the size of the work and how it needs to be manipulated. This includes bench lamps, hand lamps and crossfires fixed to the lathes.
A single project can require the use of each type of lamp at different times during construction.
Lathe work using crossfires…just one of several pieces of equipment used to heat glass for manipulation.
Forming a flange at the lathe.
While glassblowers use heat to achieve a working temperature, manipulation of glass is performed away from the flame.
“A feel for the increasing resistance to flow due to air cooling along with delicate amounts of air pressure from blowing is used to change diameter and wall thickness, pull, bend and shape glass,” says Ms Ryan.
Depending on the piece, a variety of sealing and forming techniques, cutting techniques and cold working equipment may be used.
For new work, some trial and error is involved in working out how to achieve a particular seal or shape, decisions are made about the order of construction, and how to manage all the things that may go wrong.
Multi-layered pieces.
For multi-layered glass, sections of glass are prepared through forming, often using carbon tools and cutting. The internal section is packed into an outer shell which is then heated. The areas which require a third layer are intensely heated, holes picked out and a pre-prepared section fused on. The glass piece is then flame annealed and oven annealed to remove introduced strain.
Hermit crab photo: supplied by the New Zealand Marine Studies Centre.
In 2009, staff at the New Zealand Marine Sciences Centre found themselves wondering how hermit crabs manage to squeeze their entire bodies into the small shells they call home.
To answer that question, they enlisted the expertise of Ms Ryan to design and create a custom-made replica shell home fit for a hermit crab.
It was the first time Ms Ryan had ever worked on producing a shell and the entire concept took about a month to work out.
Just one week after placing the finished glass shell in the tank, one of the aquarium’s resident hermit crabs silently checked it out, sliding his soft abdomen in to test its delicate curves for fit, ultimately making it his home
And with that, aquarium staff had their answer.
Thanks to the glass walls of its unique home, it is easy to see how the crab twists its abdomen around the central column of the shell and the well-adapted tip of the abdomen clasps strongly to hold it in place.
Pyramidal neuron photos: Blake Porter.
Among the Unit’s most unique creations of late is a pair of glass pyramidal neurons commissioned by Blake Porter, a Postdoctoral Fellow in the Department of Psychology, for use during the New Zealand International Science Festival in 2016.
The intricate models incorporate LED lights and copper spirals to demonstrate how new learning is transmitted through electrical pulses between neurons and how multiple inputs amplify the flow and reinforce learning. The glass version needed to house both a motherboard and multiple outlets through which wire could meticulously be fed through.
Dr Porter’s pyramidal neuron project, which was sponsored by the Brain Health Research Centre and Department of Psychology, is a good example of the unique artistry and effort that goes into creating custom-made pieces.
“For custom made glassware, we need to understand the special requirements of the customer and match this with their budget, time constraints and availability of materials.
“While not technically difficult it was a pleasure to work with Blake and involved some artistic licence. The finished pair of neurons was aesthetic and complete with flashing lights,” says Ms Ryan.
Filtration apparatus and an organ bath manufactured in the workshop.
The Glassblowing Unit includes a sizeable storeroom for commercially manufactured glassware.
The Unit’s on-site laboratory glassware store stocks a comprehensive range of standard laboratory glassware. With the shelves stacked high with all manner of glassware, Ms Ryan admits it’s not high on her list of places she’d want to be during an earthquake.
Thankfully, she reckons, the workshop where she spends most of her time, "poses no greater problem than my own living room at home".