A difficult problem
Right now you can experience the collections in a new and exciting presentation - including some works which have been treated in the Conservation Department. Louise Cone has worked with Æterlegeme by Claus Carstensen and describes her work in the following.
An untraditional mix of materials
Claus Carstensen’s palette consists of more than just colour. To this monumental oil painting he has applied thick grease, soft foam rubber, and his own urine. This is an interesting mix of materials which begs to comment upon the question of impermanence in art.
The foam was in need of a face-lift
After being in storage for many years, Æterlegeme was in need of a ‘face-lift’. Many of the foam pieces, attached to the painted canvas by staples, had detached from the surface. Some had been previously reattached in the wrong position, and still others were torn in half. Besides that, the foam had already started to degrade. The grease had got smudged and is visible both on the canvas and on the foam. The dust and other forms of debris which have settled on the grease are there to stay - the sticky surface picks up everything in its midst.
Æterlegeme has what conservators like to call ‘inherent vice’. That is to say that the problems are built into the work upon its creation. In this case by putting different materials together to form a composite artwork with different ageing and behavioural properties. So the process of conserving such an artwork is confounded by the interrelation between the materials - their co-existence can be threatened by the degradation of one of their parts.
The conservation process for Æterlegeme included reattaching the foam pieces to their original positions, as well as gluing the torn pieces back together. The whole painting was cleaned by using a tweezers to pluck the visible dirt, hair, and pieces of crumbled foam out of the grease.
Degradation of polyurethane foam
The degradation of the foam is the most worrisome aspect of this artwork. The soft foam rubber or polyurethane (PU) used in Æterlegeme, has a normal life expectancy of about 25 years, after which time it begins to crumble. You can see crumbling on the surface of some of the thinner foam pieces. The long polymer chains break into shorter segments; hence the crumbling. This process is accelerated by heat and light - it is also irreversible. A solution to this problem remains to be found.
But long before that happens, it will begin to change color. It takes no more than a few months for the color to change. We are already witness to this process in Æterlegeme: the foam has changed colour from white to yellow and from blue to green. Deterioration can be due to various factors - in this case the colour change is caused by ultraviolet radiation found in daylight. Further damage is caused by the material being exposed to oxygen and ozone in the air.
We cannot ask Rembrandt why and how he used a certain color or varnish - but we can and should ask our contemporary artists. Claus Carstensen has also been consulted in the conservation of his work, and has given us some very important information upon which to base our decisions relating to conservation. The artist thinks that the integrity of the work would be damaged by replacing parts of the degraded foam, by falsely making the new pieces blend in with the old. Instead he suggests that all the foam pieces should be replaced with new foam pieces - but only when the foam has fully degraded.
In Æterlegeme the artist’s wishes have been respected. There are no new parts - yet. But how far can we go to preserve the integrity of the work? The jury is still out regarding the questions raised during the conservation of Æterlegeme - questions which reflect many of the same challenges we meet with the conservation of many contemporary works of art.
Conservator, Contemporary Art