Tim Padfield’s Contribution to Conservation

Everything started from a website that proved to be a turning point in my professional and personal life. When I was reading for my master’s degree course in 2003, I was lectured by Bent Eshøj, former Head of Master Education and Research Lab at the School of Conservation in Copenhagen, Denmark. Upon noting my growing interest in museum microclimates and on how to protect paintings from unstable relative humidity, Bent strongly advised me to visit the following hyperlink: www.conservationphysics.org.1

The link directs visitors to an educational website that serves as a comprehensive guidebook on how to identify environmental risks to collections. The site provides advice on how to evaluate museum environments using scientific equipment that can be purchased and configured even with limited budgets. There are also ample recommendations on how to interpret and present the acquired data. Several measures that can mitigate environmental risks and effectively extend the lifetime of artefacts are discussed. The information is neatly collated and presented in seven major sections. Those who wish to learn more can view and download the full version of numerous papers that were published in authoritative peerreviewed scientific journals, free of charge. The text is illustrated with coloured drawings that, whilst helping visitors to better understand the content, often tend to lean towards satire in an evident attempt to make the scientific content enjoyable and less intimidating. The credentials of the website’s sole author – Tim Padfield – certainly adds weight and validates the website’s content.

About Tim Padfield

Tim was born in 1937 in Shanklin, England. He obtained his master’s degree in chemistry from Oxford University and his PhD from the Technical University of Denmark. He worked as a scientist at the Victoria and Albert Museum, University of Leeds, Smithsonian Institute, National Museum of Denmark, and at the Technical University of Denmark. Eventually, he worked as a freelance consultant in preventive conservation.

Tim was chiefly interested in evaluating historic building structures. Such evaluations included the analysis of the structure’s fabric, building technique, and observation of how buildings shelter their contents from external weather conditions. He evaluated the adequacy of a building for the display and storage of artefacts. Tim was an ardent technophile and very knowledgeable in Heating, Ventilation, and Air Conditioning (HVAC). Yet he always advocated for passive climate control, opting first for practical and low-budget solutions, to effectively improve microclimates that favour the preservation of artefacts. Such studies often led Tim to compare the microclimate control obtained in historic buildings with modern and contemporary structures. He looked at recent construction methods with a critical eye, often emphasising the necessity of learning from our past to achieve even smarter and greener solutions.2

An Insight into Tim's Research

Of course, I was primarily engrossed with Tim’s findings that were related to my studies. These included experiments conducted on cold walls and their detrimental effect on paintings. Another interesting subject included in this study referred to the disadvantages of using silica gel to stabilise the relative humidity inside showcases, especially when exposed to a temperature gradient. Tim’s website provided invaluable assistance, particularly in its detailing the methodology employed for the monitoring within museums and churches. When faced with complex situations, he conducted tests in controlled laboratory conditions to narrow the number of environmental variables. Tim was creative and resourceful in his experimental methodology. He often built customised experimental setups that can, for instance, mimic temperature changes in walls so that he could observe how this factor affected the paintings’ state of conservation. As I kept revisiting the conservation physics website and learnt more about the experiments conducted, I unravelled more aspects related to the complex interaction of paintings with air and moisture. This led me to send a short note of gratitude to the website’s author.

Tim replied promptly, assuring me that he would be happy to answer any questions that might be useful in my studies. I am sure he must have regretted the latter offer as I asked numerous questions. Yet, he pleasantly continued to reply to my many inquiries and even took a keen interest in my study. This led to lengthy discussions that mostly revolved around the sealing of paintings designed to stabilise their moisture content and limit further paint cracks and losses. Tim occasionally involved the intervention of other conservators and scientists in our discussions, including Bent and Morten Ryhl-Svendsen. Urging me to continue my research, he often advised me to learn computer programming to build customised circuit boards with miniature sensors. His technical knowledge was vast, as he kept abreast with the latest technology, sourcing modular equipment, and using opensourced software that was applicable to his experimental methodology.

For instance, he explained in detail the ingenious method of constantly measuring the surface temperature and relative humidity of a paintings’ front, reverse side, and of the wall present behind it. The latter challenging task was carried out by measuring surface temperatures with the minute tip of Type K thermocouple wires and, instead of using bulkier relative humidity sensors, he managed to extrapolate the relative humidity values at each surface from the mixing ratio obtained from a nearby thermohygrometer.

Our emails eventually shed all formalities and morphed into a friendly discussion, often ending emails with a note on our personal lives. We first met in person in November 2007, at a conference on museum microclimates held at the National Museum of Denmark in Copenhagen. Being an admirer of his work and grateful for his assistance, I felt very much like a fan meeting a celebrity, taking the opportunity to take photographs and asking for his autograph. I learnt that Tim formed part of the conference’s scientific committee and of the proceeding’s editors.3 The conference was a great success as numerous case studies and experiments were presented, leading to a lengthy discussion on the pros and cons of setting museum environmental standards. Together with several other authoritative researchers, such as David Thickett, Stephen Hackney, Marion Mecklenburg, Bent Eshøj, James Druzik, and Jørgen Wadum, this conference set another important milestone in preventive conservation.

Tim’s contribution to Malta

Tim’s ties with Malta materialised when he was invited by Heritage Malta to deliver lectures. He also inspected museums and proposed passive climate control measures, particularly for the former National Museum of Fine Arts in Valletta. The latter historic building captivated his attention as it provided him with an insight of traditional Maltese building techniques. He was intrigued by the thermal insulation of thick limestone walls and by the material’s porosity that contributed to buffering the museum’s internal relative humidity. Consequently, Tim was invited by other local organisations, and this presented further possibilities for us to meet.

I vividly recall his faint smile as he inspected every room of my old residence, admitting his temptation of installing wired sensors to the roof. He was eager to learn more about the deffun roofing and to test how this lime-based material contributes to keeping interior spaces cool during hot summers. He pondered, for instance, on the drop of temperature as dew evaporates during daytime. This provoked his inquisitive nature, always posing new questions that sprouted fresh projects which kept him busy and engrossed in his work.

I treasure his awed expression as we visited the prehistoric structures of Ħaġar Qim and Mnajdra, while vivedly recall his inspection of the tool marks in the Misqa water tanks. And whilst strolling on the garigue along the coast, eyeing the shrubs and stopping at every minute wild orchid that caught his attention, underlining the importance of safeguarding our natural ‘rock gardens’.

Bidding farewell…

Although Tim was an extremely competent and a seasoned scientist, he remained humble and down to earth, while valuing others’ opinions. I feel honoured that I could assist him with information on local case studies and was incredulous when he requested me to review his last paper – that related to the back protection of canvas paintings – before submitting it for publication.

A few months later, in 2020, I received the saddest news. Tim passed away peacefully at the venerable age of 82. When someone dear departs, part of us dies along with them, leaving a permanent void. Yet we try to keep them alive with memoirs that hark back to precious memories. I relive many happy moments every time I view old photographs, go through past email correspondences, and most of all by revisiting the conservation physics website that, thanks to his family, continues to inspire and assist others throughout their research.

Acknowledgements

The author would like to thank his wife Melissa, Frances Padfield, Anthony Spagnol, JoAnn Cassar, Godwin Vella, Rachel Vella, Andrei Azzopardi, Bent Eshøj, and Margaret Abdilla Cunningham.

NB: All images in this article were provided by the author

Notes and References

1 Padfield Tim, 2019, Physics in Conservation, [accessed 03 February 2023], https:// conservationphysics.org/

2 Borchersen, K., & Padfield, T. (Eds.). (2003). Museum Microclimates, The National Museum of Denmark.

3 ‘Museum Microclimate’, Abstracts of the Copenhagen Conference 19-23 November 2007, Padfield Tim and Borchersen Karen, (eds), [accessed 03 February 2023]: https://natmus.dk/fileadmin/ user_upload/Editor/natmus/bevaringsafdelingen/ billeder/M_M/Museum_Microclimate/ Proceedings/poster-bog-150.pdf