The use of cyanoacrylates and Butvar B76 polyvinyl

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

BUTVAR 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: cyanoacrylate Manufacturer: 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: cyanoacrylate Manufacturer: 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 Trade Name: Butvar Grade: B-76 Chemical name: polyvinyl butyral Manufacturer: Monsanto Date of purchase: 1986 Penetrates, strong, insoluble Trade Name: Krazy Glue® Grade: 201 ethyl white cap (low viscosity) Chemical name: cyanoacrylate Manufacturer: Borden, Inc. Date of purchase: 1994

IGM 100/977 fifteen years ago

IGM 100/977 now

2, 000 gallons (7, 570 liters) of fuel On the road from Ulaanbaatar, 1993

UKHAA TOLGOD

An oviraptorid in-situ Typical Ukhaa Tolgod preservation

broken bone in cross-section Bone is soft, porous and weak

Excavating ”Big Mama”

Plastic eyedropper for dispensing Extraction impossible without consolidation Heavy consolidation with Butvar B-76 is essential

“Big Mama” Oviraptorid in brooding posture over nest of eggs Prepared with Butvar B-76

Two oviraptorids juvenile protoceratopcians Prepared with Butvar B-76 Photos Mick Ellison

140 lb. (63. 5 kg) barrel Date of purchase: 1986 Butvar B-76 has a long shelf life and is a very stable material 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 more commonly available solvent a rare bottle of lab grade ethanol

Butvar B-76 coatings are very easily re-dissolved and reworked

Butvar B-76 coatings are weakly adhesive… …and easy to peel off.

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

Saichangurvel davidsoni • Heavy coatings can be reduced later • Shallow, weak consolidation does not interfere with preparation • Butvar B-76 has an aesthetically pleasing matte finish Photo Mick Ellison

Return to Ukhaa Tolgod 1994

Specimen in-situ

Mononykus?

Casts and mount - Dennis Wilson and Marilyn Fox Photo- Mick Ellison Forelimb of Mononykus olecranus

? The first complete skull ?

Heavy consolidation with Butvar B-76

Preparation from bottom AMNH prep lab 1994

Preparation up toward consolidated surface…

Preparation halted

Fibers associated with bones

Feathers Fibers- no adhesive present SEM images show similar structure

Isolated fibers embedded in LR White acrylic and thin-sectioned • Digestion with cellulase – not plant or fungus • Transmission electron microscopyhollow structure • Time of flight secondary ion mass spectroscopy – original molecules present • Immunohistological studies- beta-keratin in fibers is comparable to beta-keratin in feathers

Schweitzer, M. H. et al. 1999. Betakeratin specific immunological reactivity in feather-like structures of the Cretaceous alvarezsaurid, Shuvuuia deserti. Journal of Experimental Zoology (Mol Dev Evol) 285: 146 -157. Direct evidence that IGM 100/977 was covered with feathers

Skull separated from postcrania for continued preparation Why cyanoacrylates?

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. 87120, In Chiappe and Witmer (eds. ). Mesozoic Birds: Above the Heads of Dinosaurs. Univ. of Cal. Press

Shuvuuia deserti 2000 Exhibition 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

2000 Shuvuuia deserti on exhibit

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

SOLUTION ADHESIVE (sets by evaporation of a solvent) REACTION ADHESIVE (sets by irreversible chemical reaction) BUTVAR Shallow, weak, resoluble Penetrates, strong, insoluble 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: cyanoacrylate Manufacturer: Borden, Inc. Date of purchase: 1994

The scientific value of this specimen has depended and will depend on Butvar B-76 BUTVAR Shallow, weak, resoluble • • 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

The scientific value of this specimen has depended and will depend on Krazy Glue® BUTVAR Penetrates, strong, insoluble • • 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

Paraloid B-72 + Consolidation: Butvar B-98 ( Cyanoacrylates? ( Joining: + Archival Housing

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