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