Damage assessment of heritage objects and methods used in their preventive conservation. A talk by Dr Marianne Odlyha.

This post was contributed by Bryony Stewart-Seume, a Senior Administrator in the School of Science.

Science Week continued with a lecture given by Dr Marianne Odlyha, concerning ways in which heritage objects can be damaged over time, and recent research into the methods which can be employed to minimise risk and decay. The lecture was well attended and well received.

After being introduced by Professor Nick Keep, the Dean of the School of Science, Dr Odlyha gave some background to the project on which she has been working for some time; “Measurement, Effect Assessment and Mitigation of Pollutant Impact on Movable Cultural Assets – Innovative Research for Market Transfer.” Essentially this research looks at the different environments in which moveable cultural objects (paintings, artefacts, tapestries, etc…) are displayed, stored or transported and to what pollutants these conditions may subject the objects.

Dr Odlyha began by explaining that the research is an interdisciplinary area; it encompasses many academic fields ranging from Art History to hardcore Science. The key objective of the work is to retard the degradation and decay of objects as much as possible. A description of the corrosion found in the organ pipes in the St James Church in Lübeck, Germany was given as a case study, and as an example of a situation that could have benefitted greatly from better environmental monitoring systems.  The organ is now sadly in a terrible state, and is unplayable.

It is of course unfortunate that the material of choice for the construction of organs (oak) is a high emitter of damaging gases. This issue is exacerbated by the fact that organs (and other such items of cultural worth) are often located in places with central heating, which is there for the comfort and convenience of the audience.

I was surprised that, despite being a method of display for many years, even something as apparently innocuous as the wood from which a case is built can cause damage over time. Plywood, for example, gives off very strong emissions; of course the cases in which paintings are kept in storage (Dr Odlyha used the example of the Tate’s store to highlight her point) are primarily built from this material. There is a legitimate economic reason for this, but perhaps this is offset against the damage potential?  While showcases will keep out much of the outside pollutants, it seems that it is just as important to be aware that the climate on the inside will also have a noticeable effect on the item on display.

Similarly, the practice of using varnish on a painting is an old one, and was originally thought to do some good. It does have the effect of darkening the image and enhancing colour saturation; however, as Dr Odlyha told us, over time the painting may start to yellow. It is not only the varnish itself that can inflict damage on the painting, but also the method of cleaning employed. It is also important to know that when we find a solution that minimises the damage potential of one polluting factor, we may have merely introduced another. The cycle of material selection/damage dealt is apparently perpetual, and it is only through cutting edge, up to the minute research that we can hope to do what can be considered best for our heritage.

There are options, though, for mitigating the risks to movable objects; one of those being a so-called ‘Micro-Climate Frame’. The conditions on the insides of the frames are measured using custom-made dosimeters and compared with the ambient atmosphere. Fluctuations in the surroundings have proven to be far more severe than within the frames themselves. Of course this is good news, and what is expected, but Dr Odlyha admitted that there is still much research to be done in this area.

You can find out more about Dr Odlyha’s research at http://www.memori-project.eu/memori_project.html


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