This amazing piece is a Rhinocerus Hornbill beak with a magnificent casque. The Bird originates from South East Asia and is an endangered species. This, probably Victorian example has chinese imagery carved into the casque depicting figures, landscapes and houses which no doubt describes a story (I wish I knew more!)
The casque, which is formed of keratin is paper thin. Many years ago it had been broken and repaired. Today the breaks have failed and areas were missing so that it could no longer attach to the beak. It is fragile, and de-laminating – you can see the pink of the delaminated areas in the photograph.
The old repair had shrunk, and pulled the casque out of shape. It had been repaired using bent ivory strips, and canvass had been glued to the inside of the casque using an animal glue. Old areas of loss had been filled with a (now grey) material. The whole casque had been varnished, the varnish, now yellowed obscures the carved decoration an has attached dirt.
The first task was to ensure that the delaminating areas were secure and attached to the casque, at the tsame time these areas needed to be cleaned. The fragile edges were consolidated with a conservation grade adhesive and weak areas were supported temporarily with a tissue adhered inside the casque. Once these adhesives were set a mix of weak solvents was used to lift the varnish and as I came across them, the small fragments which had come with the object were re-attached.
The grey material softened in warmed de-ionised water and could be lifted off by picking it off with sharpened wooden picks, using a x10 magnifier to aid the work. Delaminating areas were secured with conservation grade adhesive.
Once it was cleaned it was time to re-construct the casque so that it could be re-attached to the beak. The reconstruction had to bear the weight and retain the shape of the casque and be able to mould into the casque shape. A plaster impregnated bandage was chosen to be used in conjunction with lens tissue, which would be malleable, would prevent seepage of plaster into the structure and would provide a smooth surface for colour matching.
The reconstruction had to be done in one ‘sitting’ so that the casque could be reconstructed in three dimensions without putting any extra strain on the fragile casque itself. The edges of the plaster would attach to the inside of the casque, while the lens tissue which was cut to be longer than the plaster would provide the final attachment to the beak.
Acrylic adhesive was painted onto the inside edge of the casque. A mix of water and adhesive was painted onto the edge of the plaster bandage. The bandage was softened and attached to the inner 10mm of the casque edges. Once the plaster was in place, the pre-cut lens tissue was attached to the outer surface of the plaster bandage. The plaster/tissue was then moulded into position.
Once the shape of the bandage and the position of the tissue was established for re-attachment, the lens tissue could be attached to the beak using acrylic adhesive.
A slip of plaster was then appied to build the plaster/tissue up to the surface level.
And breath! The hornbill was allowed to dry.
Lastly, using watercolurs, the infills were touch in to match the colour of the casque.