the use of cyanoacrylates and butvar b-76 (polyvinyl butyral) on a specimen of shuvuuia deserti (igm...
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The use of cyanoacrylates and Butvar B-76 (polyvinyl butyral) on a specimen of
Shuvuuia deserti (IGM 100/977)from Ukhaa Tolgod, Gobi Desert, Mongolia
Amy Davidson Division of Paleontology, American Museum of Natural History
The use of cyanoacrylates and Butvar B-76 (polyvinyl butyral) on a specimen of
Shuvuuia deserti (IGM 100/977)from Ukhaa Tolgod, Gobi Desert, Mongolia
Specimen in preparation, 1994
Trade Name: Butvar Trade Name: Krazy Glue®
BUTVAR
Trade Name: Butvar Grade: B-76 Chemical name: polyvinyl butyral Manufacturer: Monsanto Date of purchase: 1986
Trade Name: Krazy Glue®
Grade: 201 ethyl white cap (low viscosity)Chemical name: cyanoacrylateManufacturer: Borden, Inc. Date of purchase: 1994
BUTVAR
Trade Name: Butvar Grade: B-76 Chemical name: polyvinyl butyral Manufacturer: Monsanto Date of purchase: 1986
Trade Name: Krazy Glue®
Grade: 201 ethyl white cap (low viscosity)Chemical name: cyanoacrylateManufacturer: Borden, Inc. Date of purchase: 1994
SOLUTION ADHESIVE(sets by evaporation of a solvent)
REACTION ADHESIVE(sets by irreversible chemical reaction)
BUTVAR
Trade Name: Butvar Grade: B-76 Chemical name: polyvinyl butyral Manufacturer: Monsanto Date of purchase: 1986
Trade Name: Krazy Glue®
Grade: 201 ethyl white cap (low viscosity)Chemical name: cyanoacrylateManufacturer: Borden, Inc. Date of purchase: 1994
SOLUTION ADHESIVE(sets by evaporation of a solvent)
REACTION ADHESIVE(sets by irreversible chemical reaction)
BUTVAR
Shallow, weak, resoluble Penetrates, strong, insoluble
IGM 100/977 fifteen years ago
IGM 100/977 now
On the road from Ulaanbaatar, 1993
2,000 gallons (7,570 liters) of fuel
UKHAA TOLGOD
An oviraptorid in-situ
Typical Ukhaa Tolgod preservation
Bone is soft, porous and weak
broken bone in cross-section
Excavating ”Big Mama”
Heavy consolidation with Butvar B-76 is essential
Extraction impossible without consolidation
Plastic eyedropper for dispensing
“Big Mama”Prepared withButvar B-76
Oviraptorid in brooding posture over nest of eggs
Two oviraptorids
Prepared with Butvar B-76
juvenile protoceratopcians
Photos Mick Ellison
Butvar B-76 has a long shelf life and is a very stable material
140 lb. (63.5 kg) barrel Date of purchase: 1986
Feller, R.L. et al. 2007. Photochemical deterioration of poly (vinylbutyral) in the range of wavelengths from middle ultraviolet to the visible. Polymer Degradation and Stability 92 (5): 920-931.
Butvar B-76 is soluble in a wide range of solvents
a rare bottle of lab grade ethanol
a more commonly available solvent
Butvar B-76 coatings are very easily re-dissolved and reworked
…and easy to peel off.
Butvar B-76 coatings are weakly adhesive…
Matrix is consolidated yet easily removed
Butvar B-76 can be mixed with ground matrix to form a paste
Butvar B-76 and matrix pastes are strong yet easily reworked or removed
Butvar B-76 is a shallow but effective surface consolidant
Photo Mick Ellison
• Heavy coatings can be reduced later
• Shallow, weak consolidation does not interfere with preparation
• Butvar B-76 has an aesthetically pleasing matte finish
Saichangurvel davidsoni
Return to Ukhaa Tolgod 1994
Specimen in-situ
Mononykus?
Forelimb of Mononykus olecranusCasts and mount - Dennis Wilson and Marilyn FoxPhoto- Mick Ellison
?
The first complete skull ?
Heavy consolidation with Butvar B-76
AMNH prep lab1994
Preparation from bottom
Preparation up toward consolidated surface…
Preparation halted
Fibers associated with bones
SEM images show similar structure
Feathers Fibers- no adhesive present
• Digestion with cellulase – not plant or fungus
• Transmission electron microscopy- hollow structure
• Time of flight secondary ion mass spectroscopy –original molecules present
• Immunohistological studies-
beta-keratin in fibers is comparable to beta-keratin in feathers
Isolated fibers embedded in LR White acrylic and thin-sectioned
Direct evidence that IGM 100/977 was covered with feathers
Schweitzer,M.H. et al. 1999. Beta-keratin specific immunological reactivity in feather-like structures of the Cretaceous alvarezsaurid, Shuvuuia deserti. Journal of Experimental Zoology (Mol Dev Evol) 285:146-157.
Why cyanoacrylates?
Skull separated from postcrania for continued preparation
Cyanoacrylates are effective micro-consolidants- can wick into tiny cracks and pores
Cyanoacrylates form extremely thin, hard coatings
Cyanoacrylate coatings are insoluble but can be softened and removed on a tiny scale
The tiny teeth of IGM 100/977
Cyanoacrylates can be applied in extremely tiny drops
Krazy Glue® Type 201 Ethyl White Cap™ Date of purchase: 1994
Aron Alpha ® Industrial Krazy Glue Type 201
Date of Purchase: 2009
How will they age?
Down, J.L. and E. Kaminska. 2006. A preliminary study of the degradation of cyanoacrylate adhesives in the presence and absence of fossil material. Journal of Vertebrate Paleontology 26 (3): 519-525.
How to make this strong enough to handle?
Reinforcement with Butvar B-76 and matrix
Cyanoacrylate and fiberglass armature
Attaching a removable armature
Butvar B-76 and matrix paste over armature to build handle
before after
First known skull for Alvarezsauridae, used to describe the new taxon Shuvuuia deserti
Chiappe et al. 1998. The skull of a relative of the stem-group bird Mononykus. Nature 392: 275-277
Chiappe et al. 2002. The Cretaceous, short-armed Alvarezsauridae: Mononykus and its kin. Pgs. 87-120, In Chiappe and Witmer (eds.). Mesozoic Birds: Above the Heads of Dinosaurs. Univ. of Cal. Press
2000 Exhibition
Shuvuuia deserti
Model by Dennis Wilson- Pangaea Design
Reconstruction for Exhibit
For exhibit
Reconstructed plaster jacket
Brazed brass armature
Filled with Butvar B-76 and matrix paste
Shuvuuia deserti on exhibit
2000
Research and temporary storage
Research and temporary storage
Research and temporary storage
a cushioned “cavity mount” made without adhesives
Damage 2007
Future repairs and preparation
Trade Name: Butvar Grade: B-76 Chemical name: polyvinyl butyral Manufacturer: Monsanto Date of purchase: 1986
Trade Name: Krazy Glue®
Grade: 201 ethyl white cap (low viscosity)Chemical name: cyanoacrylateManufacturer: Borden, Inc. Date of purchase: 1994
SOLUTION ADHESIVE(sets by evaporation of a solvent)
REACTION ADHESIVE(sets by irreversible chemical reaction)
BUTVAR
Shallow, weak, resoluble Penetrates, strong, insoluble
BUTVAR
The scientific value of this specimen has depended and will depend on Butvar B-76
• Strengthened enough for safe collecting from a remote locality• Did not impede gentle removal of matrix from fragile bone• Did not impede recognition, extraction and analysis of feather fibers• Strengthened fragile skull with matrix paste for extensive handling• Allowed reversible reconstruction for exhibit • Will not impede further preparation• Resistant to deterioration over time
Shallow, weak, resoluble
BUTVAR
• Strengthened fragile skull bones and teeth allows handling • Fiberglass armature inside handle allows handling• Small scale use will not impede further preparation• Probably resistant to significant deterioration in tiny amounts
as a consolidant/coating
The scientific value of this specimen has depended and will depend on Krazy Glue®
Penetrates, strong, insoluble
Consolidation:
Butvar B-98 + + Archival Housing
Joining:Paraloid B-72
Cyanoacrylates?(
(
Paraloid B-72 for joining breaks
Housings reduce shuffling and handling
Housings help adhesives hold the specimen together
Future consolidation: Butvar B-98 if possible cyanoacrylates if necessary