Cassy Cutulle
Objects Conservation Portfolio
The Horniman Museum Internship
February-July 2014
The second of my five-month internships took place at the Horniman Museum in South London. While at the Horniman Museum I was able to participate in a wide variety of conservation-related activities, including treatment work, training workshops, environmental monitoring, integrated pest management, instrumental analysis, as well as loans and accessions processing. Opportunities to test and research materials were welcomed and abundant, providing me with the technical knowledge to confidently pursue my professional career. A full report of my work at the Horniman Museum is available below.
Report #3
©The Horniman Museum, London. Report #3 may not be reproduced.
TREATMENT OF TIBETAN CLAY FIGURINES
BEFORE FRONT AFTER FRONT
CONTEXTUAL INFORMATION
A group of approximately forty-three unfired clay Tibetan figurines were given to the Horniman Museum in 1951 by the Victoria & Albert Museum. These figurines had been collected by Sir Thomas Forsyth throughout his travels in late 19th-century Ladakh. A group of sixteen were chosen from the larger group to be displayed in a temporary exhibition in the Centenary Gallery of the Horniman Museum. This display would exhibit the figures in a hierarchical fashion, based on the religious statuses of the figures in Tibetan Buddhism. My job was to treat four of the figurines that were to be put on display. The summary below details the treatment understaken for the one of the figurines, "Virudhaka" [See Above Images].
PRE-TREATMENT CONDITION
Cleaning and restoration work was needed on each figure to varying degrees. All of the figures contained some dirt and dust on the surface that needed cleaning. The reverse side of the base exhibited cracking in the clay—most likely due to storage in a dry or variable relative humidity (RH)/temperature environment. This figurine has also lost two fingers on its proper right hand that were originally creating a symbolic gesture.
REASON FOR TREATMENT
Treatment of these figurines were requested in preparation of the exhibition, "Figures from the Roof of the World". Restoration of the figures was desired so that the iconographical aspects of the figures would once again be complete, reestablishing their original symbolism and meaning for public display.
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For more information regarding this exhibition, please visit:
(Above Left) Image of the Virudhaka figurine during the restoration of the fingers on its proper right hand.
(Above Right) Image of the Virudhaka figurine prior to consolidation of the reverse side of the base.
CLEANING, STABILIZATION AND RESTORATION
The Virudhaka figurine was lightly cleaned using a Royal Fine Sable® brush and air puffer to remove dust and light particulate matter. The friable clay exposed on the reverse side of the base was consolidated using ParaloidTM B-72 5% w/v in acetone.
To better understand how to approach the restoration of these figurines, a consultation with a Tibetan Buddhist Lama—Lama Zangmo—was undertaken in mid-February. This gave me the opportunity to understand the iconography to determine what the missing portions should look like. This meeting also further exemplified the value and importance of collaboration in conservation and restoration.
On the proper right hand of the figurine, a new finger was created using Aves® paper mache in reverse osmosis (RO) water and shaped using a no. 15 scalpel and light abrasive paper. It was adhered with ParaloidTM B-72 20-25% w/v in 1:1 acetone:ethanol, applied with a toothpick. The area of loss between the index finger and the rest of the hand was in-filled with paper mache and reinforced with a small amount of ParaloidTM B-72 10% w/v in 1:1 acetone:ethanol. Both paper mache fills were in-painted with Liquitex® and Galeria® acrylic pigments. The fibre cordage at the tip of the index finger was also tinted with this color to make it less visually distracting.
CONDITION AFTER TREATMENT
As a result of this treatment, the figurines are now stabilized and the iconography for each has been aesthetically restored. Any loose portions or friable clay have been secured. The results of this project provided an informative display about the religious hierarchy of Tibetan Buddhism while demonstrating the diversity in materials and methods of manufacture for these figurines.
(Above Left) Image of me mounting the figurine in its display case in preparation for the exhibit.
(Above Right) Image of me with the figurines mounted in the display case.
Treatment of Tibetan Clay Figurines, The Horniman Museum.
Photographs by the Horniman Museum and Cassy Cutulle
©The Horniman Museum, London. Images may not be reproduced.
CONSERVATION OF FLUID-PRESERVED SPECIMENS WORKSHOP
(Above Left) Image of the marine worms before treatment.
(Above Right) Detail image of the marine worms before treatment. Note the dried-out nature of the worms as a result of the evaporation of the fluid preservative.
WORKSHOP INFORMATION
At the Horniman Museum I was also fortunate enough to be able to take part in interesting and informative workshops to add to my burgeoning conservation knowledge-base. One such workshop was the Fluid-Preserved Specimens workshop which focused on the conservation wet specimens. Under the expert guidance of Simon Moore, myself and conservators from various museums learned the theory and practice behind conserving specimens preserved in fluid. This also included supplementary training in glass cutting, drilling, mounting and the sealing of glass jars.
PRE-TREATMENT CONDITION
During this week-long workshop, I was able to conserve two different specimens-one of which is the marine worms pictured above. The worms were originally preserved in a solution of 70% alcohol which had since evaporated from the jar due to the lack of a proper seal. Since the fluid had evaporated, the worms became dehydrated and friable.
REASON FOR TREATMENT
To maintain the shape and integrity of the marine worms, it was necessary that they be rehydrated and preserved. Treatment was then undertaken to carefully hydrate and fix the worms in that state.
(Above Left) Image of the marine worms while they are being mounted to a piece of glass.
(Above Right) Image of the marine worms after treatment. They were mounted upright so as to be visible from the sides of the jar.
REHYDRATION AND FIXATION
First, the marine worms were rehydrated through submersion in Decon 90 (Emulsion of anionic and non-ionic surface active agents, stabilising agents, alkalis, non-phosphate detergent builders and sequestering agents, in an aqueous base) 5% v/v in RO water and warmed on a heating plate at between 30-50°C. After one hour, the Decon 90 solution was drained the worms were rinsed in RO water. To fix the worms in their rehydrated state, the worms were soaked in a solution of 10% Formalin (40% Formaldehyde, distilled water, disodium phosphate, and sodium dihydrogen phosphate) for sixteen hours. After fixation, the worms were rinsed in RO water again and the treatment in ethanol began. Ethanol immersion began with a 20% solution of ethanol in RO water, which continually increased by 20% every two hours until it was immersed in a solution of 80% ethanol-the final preservative solution for the worms.
A new glass jar was sourced for the worms, and a circular glass lid was cut for it. It was necessary to drill a hole through this lid so as to be able to add more ethanol in the future. This hole was plugged up with polypropylene which was covered with a circular glass cover slip. The worms were mounted to two glass pieces cut in a rectangular shapes. Mounting was done by the placing the worms on the glass, pipetting ether alcohol drops over the worms and then adding drops of 10% celloidin (concentrated pyroxylin) over the ether alcohol. This provided adequate adhesion between the worms and the glass. Waterproof labels with the solution ingredients and the accession number were placed into the jar.The glass mounts were then situated within the jar and the lid sealed to the jar using gelatine.
CONDITION AFTER TREATMENT
As a result of the treatment, the worms are rehydrated and are no longer friable. They appear more realistic and the new mounting has allowed them to be visible from the sides of the glass jar. The placement of the worms in the 80% ethanol v/v in RO water solution has allowed them to be preserved in their current state. This is a great improvement from their previous condition, whereby they were dried out and actively breaking. In all, this treatment has prevented the physical and chemical deterioration that would have occurred if the worms were not conserved.
(Above) Image of me creating a thin glass rod by heating a thicker glass rod with a blow torch. These thin rods can be used to support or mount wet specimens.
Conservation of Fluid-Preserved Specimens Workshop, The Horniman Museum.
Photographs by Cassy Cutulle.
©The Horniman Museum, London. Images may not be reproduced.
PORTABLE X-RAY FLUORESCENCE OF TAXIDERMY SPECIMENS
(Above) Image of me using the pXRF handheld analyzer to analyze a taxidermy specimen.
RESULTS
As a result of our work, we have been able to flag certain specimens as hazardous according to the materials detected and the amount present. This has helped to keep collections employees informed about toxic contaminants and the need to wear personal protective equipment. Ultimately, the hope is to produce more information on acceptable ranges of toxic materials in museum collections.
REASON FOR ANALYSIS
While interning at the Horniman Museum I was able to participate in an interesting project which involved portable x-radiography (pXRF) analysis of taxidermy specimens. Analysis of these objects is an important task because many of them are constructed with toxic preservative fillings such as mercury and arsenic. It is crucial that conservators detect these materials in order to provide hazard labels and thereby mitigate the risk of harm to those handling the specimens.
ANALYSIS SPECIFICIATIONS
To detect heavy metals such as arsenic and mercury, an Olympus InnovX Delta pXRF analyser was utilized. This allowed us to confirm the presence of these materials while also ascertaining the approximate levels at which they were present. Specifically, bird specimens at the Study Collections Centre (SCC) in North Greenwich were analysed.
For health and safety purposes, lab coats, gloves, respirators and plastic aprons were used throughout the analysis. Two conservators at a time were charged with analysis and recording of the information. A picture of the specimen was printed beforehand to label the areas which were analyzed. Information such as the kV power of the beams, the amount of beams used, the analysis mode (soil or alloy plus), areas analyzed and a brief description of the materials and concentrations detected were recorded. The electronic data collected by the pXRF was downloaded into software which then allowed us to retrieve the spectra and interpret it.
(Above) Image of me using the pXRF handheld analyzer to analyze a taxidermy specimen.
Portable X-Ray Fluorescence of Taxidermy Specimens, The Horniman Museum.
Photographs by Charlotte Ridley.
©The Horniman Museum, London. Images may not be reproduced.
REHUMIDIFICATION OF A ROMANIAN LEATHER BELT
(Above) Image of the leather belt before rehumidification treatment.
CONTEXTUAL INFORMATION
This leather belt was a part of a larger display case of Romanian folk art objects that were in need of treatment for the "Revisiting Romania-Dress and Identity" Exhibition at the Horniman Museum. The belt dates to the 19th-century and is classified as a men's work belt.
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For more information on this intriguing exhibition, please visit:
PRE-TREATMENT CONDITION
The belt was considered to be in fair condition, with some condition concerns observed. It was stored flat for several decades and had become rigid, dry and friable as a result. Some of the leather was flaking, especially around the previously bent edges.
REASON FOR TREATMENT
It was requested by the curator that the belt be displayed on a round acrylic mount for the exhibition. To do this, rehumidification of the belt was necessary.
(Above) Image of me spot testing the various colors on the leather belt to determine solubility with various solvents.
TESTING AND TREATMENT
Prior to the rehumidification of the belt, spot testing of each color of dyed leather was undertaken with ethanol, acetone, and deionized water to assess the solubility of the dyes and to determine which solvent would be suitable for the humidification atmosphere. The results of the tests confirmed that deionized water would be the best option for rehumidifying the belt.
To begin the process of rehumidification, an atmosphere was constructed out of polythene sheeting, tape and metal poles. An ultrasonic humidifier set to disperse a fine mist through a hose was used to increase the relative humidity of the atmosphere. A dial hygrometer was utilized in keeping track of the relative humidity (RH) over time. In the morning, the ultrasonic humidifier would be turned on and the RH slowly increased to approximately 75% for several hours throughout the day. The humidifier was turned off at night to prevent the risk of mold growth or corrosion on the metal fixtures. Each day, the belt was checked for increased flexibility and any signs of potential risk. During the first day the belt was situated in its pre-treated shape upon the acrylic mount, unrestrained. As the flexibility increased, more points on the belt were gently restrained to the acrylic mount using Tyvek® ties so that the belt would take on this new shape. After eight days, the belt was successfully rehumidified and reshaped for the exhibition.
CONDITION AFTER TREATMENT
The careful rehumidification of the belt allowed for the successful reshaping of it to the acrylic mount without presenting risk to the object. As a result, the belt was able to be displayed in accordance with the curator's desires while maintaining the physical integrity of the object.
(Above) Image of the humidification atmosphere set up to reshape the leather belt.
(Above) Image of the leather belt on the acrylic mount after the successful rehumidification and reshaping of it.
Treatment of a Romanian Leather Belt, The Horniman Museum.
Photographs by Charlotte Ridley and Cassy Cutulle.
©The Horniman Museum, London. Images may not be reproduced.