Many pieces of glassware found in the collections of museums suffer from a problem known as glass disease, where components of the glass break down and it becomes cloudy and weak.  When Ian Hankey was at the Royal College of Art a PhD student from the V&A museum brought him a piece of old glass from a sample of the collections.  Dr Sarah Fearn wanted to melt it to recreate the glass so that it could be speed aged, and the process taking place watched, so they could find a way to cure glass disease.  Up until that point they had been unable to melt the glass.  Hankey was the first person to manage to melt glass this old and he says as soon as he did he realised that the recipe for the glass was made by a glass maker.


Modern glass is not made to recipes developed by glassmakers but rather developed by technicians looking at chemical compositions.  What is important in these recipes is the optical clarity required in batch production under rapid conditions.  In other words glass recipes are designed to support industrial conditions, but it is not set up to be sympathetic to the maker.  Soda lime glass is hard – and difficult – because although it can be worked till it is very thin or fine it suffers easily from thermal shock, compared to lead glass, which is softer, but lumpy and thick. Hankey said that as soon as he melted the glass he saw how lovely it was to work with, and realised that old glass did not uphold the distinction between art and science:  the chemistry and the artistry involved in making glass were linked.  17th century glass had all the best attributes and qualities of modern glass but none of the adverse affects. 


The problems of industrialisation are systemic:  as industry became more dominant society required an increasingly complex structure.  Administrative and political systems became more and more specialised, with a corresponding negative effect on the craftsperson.  Once the link between the recipe and the process was broken in glassmaking the craftsperson could only specialise more.  Hankey found that the glass he had melted anneals at low temperature and melts at high temperature.  This makes the glass remarkably resistant to thermal shock but can be made very thin: previously modern skills were not up to the skills evinced in pieces in museums but Hankey has proved that the recipe (plus ways of working the glass) can now be reproduced.


 Dr David Martlew, who was head of research and development at Pilkington glass but is now a leading member of the Society of Glass Technology (incidentally he was also overseer of Dr Fearn’s PhD) has asked Hankey to talk at several international conferences. The SGT has published his paper and has asked him to speak about his latest research at a further conference at Cambridge University in September.

His paper on Working with a 17th Century Glass for the“Making and Knowing – Empirical Knowledge” conference held at the V&A Museum is to be published by Harvard University Press for Columbia University. The glass he melted has been the subject of several research projects involving collaborations between Universities and Museums including; Imperial College London and the V&A, Edinburgh University and the Museum of Scotland and Harvard University and the Boston Museum of Fine Arts.  


Hankey’s next step is to use pre-17th century methods of sustainability in terms of the design of the furnace. Modern furnaces need to be on all the time. They take a week to cool down for things like maintenance and repairs.  The problem is that the pots in which the glass is melted are very thick and heavy and can crack when the temperature drops.  Not only the pots but the interior of the furnace can be damaged if the furnace is turned off.  Clearly this represents a huge input of materials:  in the construction of the furnace itself, which has to be built to withstand that amount of constant heat, and in the running of the furnace.  In fact Hankey built a half ton furnace for Teign Valley Glass – which is a small factory – that was designed to fire for a period of 7 years without being turned off at all.  It is no wonder that glass is often the most visible energy draw in terms of applied arts courses.


Hankey has developed a kiln using a historical impetus for design.  In modern glass workshops, there are three energy consuming elements. The main furnace is where molten glass is made within the crucible; the glory hole (which is a way of reintroducing heat to glass while it’s being worked – the ones at Plymouth College of Art are set at 1200 degrees and unused most of the time); and the annealing oven.  At the moment the separate kilns are all being fired with energy, whereas in the old days there was a chamber off the furnace and the glassmaker moved the product away from the heat slowly to anneal it.  Hankey’s design uses new materials to replicate pre-17th century techniques.  It is smaller than modern kilns and, essentially, the use of two smaller crucibles (the pots that the glass is melted in) allow the furnace to be turned on and off without damage. Smaller kilns use less energy and cost less to start up as with a small business, so for students this design could mean that they could be a small start up sole owner or collective rather than having to work in factory conditions.  Firing using this small kiln and the recreated glass recipe would mean that the glass is easier to work – it teaches more about blowing glass, about the properties of glass itself, than “normal” kilned glass does.  So students learn more, and more quickly.  Aside from using less energy because of having a smaller combustion system, each element can be used separately.


This way of working is far more labour-intensive, but for Hankey this is not a negative.  With the glassmaker more in control of the materials and the process, the skills that previously were thought beyond modern knowledge are retrievable again.  It is not that the skills were necessarily lost, but that the ideological insistence on a way of working (which values speed and a mechanistic heterogeneity over tacit knowledge and a thoughtful, cradle-to-grave approach to a process and a material) has made us blind to the possibility that a different way of working could give us the skills we thought we had lost.


Hankey’s passion is for the re-evaluation of tacit skills. He feels that people who work with their hands and hearts can’t act as they feel they should because that way of acting, that thing they know they should do, is not in the job description.  In modern society with technical rationalism as its dominant model of thinking, the working practitioner has no credibility or voice.  All his work is an attempt to square the circle – joining learning and making a living, history with the future, valuing the whole person – learning as much as writing – and the kiln design is an aspect of this determination to look to the past for what could be used in the future, just as he uses a historical lens to view how tacit skills were valued in the past and how they could and should be valued again.