The History of Skeleton Preparation and Degreasing at
the South Australian Museum
David Stemmer1
1 Collection Manager of Mammals, The South Australian Museum, North Terrace, Adelaide, 5000, South Australia.
Email: [email protected]
The Early Days
Degreasing – Trial and Error
The South Australian Museum boasts the
largest and most comprehensive cetacean
collection in Australia . This was initiated by
a series of scientific staff with an interest in
marine mammals who collected important
specimens like a 17m sperm whale in 1881
Blue Whale - 1918
and a 27m blue whale in 1918.
The maceration of skeletons was done at
the Museum in Adelaide until 1967. An old
farmhouse was acquired next to the
sewage treatment works at Bolivar in 1971
which was adapted as preparation facility.
Human health and safety concerns almost
led to its closure, but the state government
funded a purpose-built specimen
Old Farmhouse
Old Maceration Tank
preparation facility which opened in 1983.
The decision to abandon the use of the toxic and dangerous TCE has led to a series of experiments to find a benign
replacement process that will work with our existing equipment:
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Methods
Aims
Treatment preserves bone
integrity
Low flammability and low toxicity
Removes internal fats
Financially viable
Cow bones
Juvenile cat bones
~Before
After
Bolivar Facility and Degreaser
The facility was fitted with a large (2800L)
custom built liquid-vapour degreaser that
used 1,1,1-Trichloroethylene (TCE) as
solvent. Many beautifully degreased
skeletons were prepared during its 15-year
operation, including a 22m pygmy blue
whale. An accidental spill of TCE in 1999 led
to the decommissioning of the unit.
Industrial Liquid-vapour Degreaser - Bolivar
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Bones were treated in flask with reflux system set into a basket heater
Various fatty cetacean bones were treated with methylene chloride to
assess fat content - these were used as comparison
Fatty dolphin vertebrae and flipper bones selected for testing
Bones weighed with precision balance before and after treatment
All chemicals first tested on fragile juvenile cat bones to assess
damage by eye, followed by fatty cow bones to assess fat removal
Water was also tested to assess its effect (because it is a component of
miscible solvents)
If no adverse effect observed, chemicals tested on dolphin bones
Results
After
Workshop with maceration vats, 2t Humpback suspended on crane
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Photos: R. Ruehle
The facility includes 6 stainless steel, 2500L,
heated macerating vats with a steel basket
partitioning system for different size
skeletons, a 5 tonne overhead gantry crane,
stainless steel hydraulic dissection tables,
cold room, industrial steam cleaner and work
space for dissecting and preparing small and
large specimens simultaneously.
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100% NeutraSolv3
(28% mass loss)
100% Eucalypt oil
(26% mass loss)
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Bones degreased with CCl2H2 had mass loss of up to 20%
Cat bones boiled in H2O had a mass loss of 22-25%
All glycol ether compounds showed some degreasing properties
Damaged bones (>30% mass loss, spongy, brittle, etc.) produced by:
Neutral, SOLV, NeutraSolv, NeutraSolv 4, LaunderSolv, Polysorbate60
and NMP
One glycol ether compound (100%), eucalyptus oil and PO65 produced
solid well-degreased bones
Conclusions
Chemicals Trialed
Methylene Chloride (CCl2H2)
Water
Glycol Ether Compounds:
SOLV
Launder SOLV
Neutral
NeutraSolv
NeutraSolv2
NeutraSolv3
NeutraSolv4
Terpenes:
Eucalyptus Oil
PO65 (Alpha-terpineol)
Other:
Rittel's Super Solvent
Ammonia Solution
N-methyl Pyrollidone (NMP)
Polysorbate60
Coasol
The observed degreasing properties of glycol ether/surfactant compounds and the excellent result of NeutraSolv3 are
encouraging and warrant further testing. However, some damage was observed and may have been caused by other additives.
These compounds are miscible with water, but this is not recommended as boiling in water is detrimental to bone. The terpenes
eucalypt oil and PO65 are good degreasers, but their flammability makes them less suitable. Although, there may be less
flammable terpenes that could proof suitable.
Where to from here ???
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Large scale experiments need to assess glycol ether compounds, terpenes and other methods (eg. enzymes and ultrasonic
cleaning)
Post-treatment solutions need to be tested for calcium and other compounds that indicate bone damage
Suggest collaborating with research chemist (may be suitable as student project)
Acknowledgements
Catherine Kemper for proof reading and useful comments on the poster. Odisseas Kehagias, from Dominant Chemicals for advice and supply of potentially suitable chemicals. Ross Goeble for assisting with the experiments. All museum staff
involved with the design and development of Bolivar, in particular John Ling, Winston Head, Peter Corkeron, John McNamara and Catherine Kemper. SA Museum for funding the trip to Europe. Gwenaël Lemoine (Arc’ Antique) and Christine Le
Gouriellec (Museum of Nantes) for organising the printing of the poster and thus saving me from carrying it half around the world . Merci beaucoup!