Wooden Artifacts Group-Friday afternoon session

Constructing Time: The Neuroaesthetics of Art as Experience

Peter Muldoon, Conservator, Smithsonian Castle

The Friday afternoon WAG session was kicked off by furniture conservator and former WAG chair Peter Muldoon’s theoretical paper, exploring questions like where does conservation come from? and why are we compelled to conserve art? He began by remarking that George Wheeler gave a talk that touched on similar issues earlier this week in the general session, but Muldoon’s presentation was much more about where to place conservation in the human experience, rather than exploring conservation theory and the identity of conservation as a profession.

Muldoon stated that his thinking on this topic has been influenced by readings in evolutionary psychology. Taking part of his title from the 1934 book Art as Experience by John Dewey, which discusses art as a social, community process, Muldoon declares that art, unlike language, is not part of human instincts, but it is part of adaptive human behavior. Muldoon explored terms such as ‘aesthetics’ and a new term, ‘neuroaesthetics’ – (he mentioned that there was a conference on this topic at UC Berkeley last year).

He reminded us that we bring our aesthetic judgment to every object we touch – we cannot marginalize aesthetics in our work. He then asked the question, what is artistic ability linked to? and answered by saying that our curiosity helps us make sense of our world and that we create meaning by creating art and narrative. Conservation helps us create meaning now.

While I found parts of this presentation a little hard to follow, I really liked these theoretical, philosophical contributions to AIC this year and how they infiltrated the specialty group sessions – I think that we should be pushing to see more of these reflective papers that directly tie into the conference theme.

Changing requirements for the museum environment: Baldachin Altar for the Holy Trinity

Aranzazu Hopkins-Barriga, Restorer, National Museum of Anthropology, Mexico

Aranzazu Hopkins-Barriga is a conservator in the ethnographic/folk art section of the National Museum of Anthropology, Mexico. Her talk really just covered the treatment of the Baldachin Holy Trinity altar, which she said is an important object in that collection, both for its materials and its history. A four-part lacquered wood object, it was made in Olinalá, a center of lacquered objects production in Mexico. It was made in 1962, and has been part of the collection since 1982.

The cracking and loss of lacquer on this object was due to several causes – apparently the wood was not completely dry when the altar was painted, and also it had been displayed for many years in a case with mixed media objects.

For treatment, the pieces of the altar were dissembled, fragments of detached lacquer were collected, and after solvent testing, water was used to clean the surface. Cracks in the wood were filled and then the lacquer fragments were readhered. Other areas were consolidated and the fills were inpainted. Finally the pieces were reunited.

Interestingly, this was the first ethnographic object from this collection to be conserved entirely – this is particularly important for carrying out the museum’s mission, which is to support Mexican artwork and cultures. The altar will be exhibited for one year and then be returned to storage.

An Experimental and Practical Study of Some Consolidation and Coating Materials for Wood and Wooden Objects

Dr. Hany Hanna Aziz Hanna, Senior Conservator, Supreme Council of Antiquities, Egypt

In this talk, Dr. Hany Hanna Aziz Hanna described tests and treatments he carried out for consolidating/coating severely deteriorated wood objects.

Using a variety of wood types, he evaluated four different coatings:

. Shellac in alcohol, 10%, 15% 20% (called gamma lac in Egypt?)

. B72 in toluene 5, 10, 15%

. PVA 5, 10, 15%–which he said is often used in the wrong way in Egypt

. 10% shellac in alcohol followed by 5% B72 in toluene – which he said is often used in Egypt for consolidation and/or coating wood

And based his evaluations on the following criteria/examinations:

. How the coatings interact with the wood

. Ease of application

. Penetration and absorption

. Setting time (he made tables to show this but he was unable to display them)

. Appearance of the wood – color, luster, and composition of film

. Microscopic examination of wood cells and walls to see interaction at this level

. Accelerated heat aging and how consolidants protect wood after aging

. Tensile strength and hardness also studied before and after aging

In the end, he chose the 10% shellac followed by 5% B72 as a coating for the wood objects he was working on, as it combined the best of both material’s properties. He explained that shellac consolidates the wood cell walls well, has a fast drying rate, and combines hardness with elasticity. Isolating with B-72 helps to protect the wood from humidity (and can also be removed easily when there is a shellac barrier).

In the second part of his talk he showed some examples of treatments in which he used this coating. I believe he indicated that he has been using this coating since 1996 for wood objects in very poor condition. In 1996 he treated three sanctuary screens, and in 1999 he treated three turned wood objects. He showed many BT and AT images, as well as SEM images of insect damage seen in some of the objects. In the images, the BT surface of the wood appeared dry and grey in color, while the AT images showed the wood looking darker and more saturated. He has monitored these treatments and after over 10 years the objects appear to be stable and fairing well.

Mapping and Predicting the Action of Organic Solvents on Wood: Search for a Dimensional Neutral Effect

Wendy Baker, Fine Art Conservator, Canadian Conservation Institute; Dr. David Grattan, Manager of Conservation Research, Canadian Conservation Institute

Wendy Baker gave a very clear, informative presentation on her work testing the effects of organic solvents on wood. After successfully treating several badly damaged polychrome objects by bulk consolidation with B72 in specific combinations of solvents in the 1990s, she wanted to investigate how a range of solvents may cause dimensional changes in wood.

She showed images of the bulk consolidation treatments, which were carried out by brushing the consolidant onto object. When carrying out consolidation treatments, we often want to decrease the evaporation rate to ensure that the consolidant fully penetrates the object – this means that the object is exposed to solvent for a long time.

So she asked: what do we know and what don’t we know about solvents and wood? What we do know is that different types of wood will respond differently, and that swelling will be greatest in the tangential direction. However, to date, there has been no equation developed that can predict, across a range of solvents, how wood will respond to different solvent exposure.

I loved how simple her experimental design was-it consisted of taking tangential sections of air-dried wood – white oak and eastern white pine (2 samples each for each solvent tested), placing 2 dissecting pins in each and then placing them in different solvent baths and measuring the distance between the pins before, during and after exposure to measure dimensional change. For her experiments, she chose solvents typically used in wood treatments.

Both types of wood responded similarly to the solvents, and in the end, she found that the response of the wood to the solvents was related to three main factors: molecular weight, polarity and solubility in water. For instance, solvents with low molecular weight can pass through the wood cell walls and cause more swelling, while those with higher molecular weights cannot, so these solvents occupy other spaces in the wood and pull water out of the cell walls, causing shrinkage. She also concluded that shrinkage seems to be worse for objects than swelling, and that while hardwood responds more slowly than softwood, it also experiences greater dimensional change.

Adhesion Coercion: An Investigation into Potential Coatings for PEG Treated Wood

Lauren Paige Isaacs, Owner, Flying Pig Art Conservation

I never imagined that I’d be listening to a paper on PEG (polyethylene glycol) at AIC that wasn’t about waterlogged organic material. But my eyes were opened during Lauren Paige’s presentation, which was the last of the day (and of the conference for most people). This was a project on a contemporary wood object that Lauren encountered during her graduate internship at MOMA, and that was first investigated by Steven Pine and published in the 2006 WAG postprints.

Edward Moulthrop was an artist who made wood turned vessels, which he plasticized with PEG for the visual effects, apparently. He died in 2003, and his methods and materials are fairly well-documented – after turning the wood vessels, he would immerse them in a 30% solution of PEG 1000 for 1-3 months before finishing them and coating with epoxy.

In recent years, Steven Pine noticed that there were blisters on one of his bowls and also patches of delaminating epoxy, which once started, was exponential. There was interest in replacing the coating in the areas of loss. To address an approach to this treatment, Lauren carried out tests using birch tongue depressors (similar in color and structure to the tulip popular used by Moulthrop), which she immersed in water, then in a solution of 50% PEG 1500 at 140?F for 36 hours (to accelerate the impregnation of the PEG due to time constraints), and then air drying them and applying several different coatings to test their adhesion and appearance.

In the end, she found that water and ethanol-based coatings were not successful, as they never fully cured, and that low molecular weight resins were not much better. She liked Epotek 301 and acrylics, including B-72, B-67 and Golden MSA. The more successful coatings were those that could wet the surface of the PEG-treated wood and form a strong surface bond – both the solubility and the molecular weight of PEG and the coatings must be considered. PEG is soluble in polar solvents, and the more successful coatings were the ones delivered in a non-polar system. Other important factors to consider were the wood structure and relative humidity.

After these results, a second round of tests were carried out on birch wood spheres, also treated with PEG, and coated with the best performers from round one with the tongue depressors. In the end she preferred Golden MSA – not only did it form a good bond, but it has the properties of being hard yet flexible, it permits both the wood and the PEG to respond to RH fluctuations, and it also looked good. Lauren also suggested that the recent “hard” version of Golden may be a better possibility but she hasn’t looked into it.

**An Update on using Reproduction Finishes as Predicators by David Bayne was the last paper on the schedule for the day but it was not presented.