Modern Wooden Sculpture
This beautiful sculpture was carved from a single piece of wood in Israel and was passed down through three generations when it fell from a first story window. The owner wanted the sculpture to be reconstructed but knew they could never forget the accident and decided they would prefer to embrace the break by gilding it in the spirit of Japanese ceramic kintsugi. They also requested that the treatment not involve any animal products, so this was my first intentionally “vegan” treatment.
Description
This object is a wooden sculpture of an unknown wood species. It was sculpted by an Israeli artist from a single piece of wood and is vertically orientated with a hollowed core. This can be understood from the clear presence of tool marks throughout the internal cavity, as well as on the surface and around the holes carved into the existing wall. The resulting sculpture takes on a biomorphic shape, with undulating lines that twist up from a circular base.
This object arrived with no associated documentation.
Condition
The sculpture fell out of a first-story window and broke into four primary pieces and some smaller shards. There were abrasions on the surface from impact and cracks occurring in the axial direction.
Cleaning
Only dry cleaning was conducted due to the sensitivity of the object and particularly the wood varnish to solvents. Dry cleaning was conducted with a synthetic paint brush and smoke sponge (vulcanised natural rubber) to remove dust and debris, though the surface was relatively clean.
Reconstruction and Repair
Reconstruction was first tested dry using FrogTape® Delicate Surface Painter’s Tape (saturated paper with proprietary acrylic adhesive). This was helpful in relocating and numbering loose shards which were reincorporated later.
The final reconstruction was started at the base, with Lascaux 498HV painted on the cross sections using a synthetic flat brush, and built up one piece at a time. FrogTape® Delicate Surface Painter’s Tape and cohesive bandages (high strength synthetic fibres, polyurethane elastic yarn, and a cohesive rubber latex compound) supported the structure as the adhesive dried. As many small pieces were reincorporated as possible, though some very small pieces remain.
Once adhesive was dry and secure, the sculpture was transferred onto a padded steel plate and rod mount lined with acid-free tissue to increase its physical security.
Loss Compensation
Gaps in the joins were filled as a base-layer to the later “bole” and gilding. A thick paste was made combining gum Arabic adhesive and Japanese Tonoko powder, worked using a steel spatula on a ceramic plate. It was then put into place using a fine Tiranti spatula. Edges of the wood were gently cleaned with cotton wool swabs and deionised water.
On top of the gap fill material, a layer of gum Arabic pigmented with Venetian red was delicately painted on using a #1 synthetic brush aided by some hot deionised water to loosen the adhesive when necessary. This aided in producing a smooth surface for the application of gold powder.
Next, Winsor & Newton watercolour pigments were used to tint areas of abrasion or colour change around joins to match the original stain. This was then finished with a microcrystalline wax and buffed.
The final step relied on FrogTape® Delicate Surface Painter’s Tape was used to line the join, then loose 24k gold powder was applied with a brush and worked in with an agate burnisher. This became challenging in hard-to-reach areas, particularly inside the sculpture. This process was repeated in areas where the red “bole” layer was still visible through the gilded layer.
Joins were then finished with a layer of 10% Paraloid B-72 w/v in acetone to seal and protect it from abrasion.
Mount
In order to prevent future accidents a custom mount was designed using moulding plastic and an iron base. It was a priority to not cause any visual disturbance so, while the mount does increase stability, it is not accident-proof.
Treatment Testing
To reconstruct the object and recreate a treatment in the spirit of Japanese ceramic kintsugi repair while avoiding animal products, significant testing was conducted.
In terms of reconstruction, animal glue would generally be used. It was thought preferable to use an organic resin sympathetic to the wood.
Tests for reconstruction included:
- Gum Arabic
- Dammar
- Gum Elimi
- Rosin
- Pale Amber Colophony
- Lascaux 498HV (dispersion of thermoplastic acrylic polymer)
Although it was desirable to use an organic plant-based resin, adhesion tests resulted in failure in all resins except Gum Arabic and Laxcaux 498HV. When tested a second time with surrogate material, Gum Arabic did not hold enough weight to keep the sculpture together. For this reason, Lascaux 498HV was chosen as the most secure option.
To fill gaps along join lines, creating the base substrate for later gilding, various loss compensation. materials were tested, including:
- 20% Mowital B30H (polyvinyl butyral) w/v in IMS (industrial methylated spirits) with calcium carbonate (CaCO3) and fumed colloidal silica
- 40% Paraloid B-72 w/v in acetone with microballoons (microscopic soda-lime borosilicate glass)
- Gum Arabic with Tonoko Bulking Agent (aluminium silicate clay)
Because Gum Arabic and Tonoko gave the smoothest result, was removable with water rather than harsher solvents, and had a sympathetic brown colour, it was chosen as the gap-filling material.
Treatment tests were conducted to determine the best method for gilding join lines to create a similar effect to kintsugi. Tests were conducted using bronze powder (given the expense of 24k gold powder).
- Bronze powder mixed with gum Arabic
- Bronze powder mixed with Paraloid B-72 15% w/v in acetone
- Loose bronze powder applied to still tacky Gum Arabic
The best result was very clearly the application of dry pigment onto gum Arabic adhesive. Although this was a complicated application, it gave the greatest lustre and meant that Gum Arabic could be used for both loss compensation, “bole” layer, and gilding.
Two options for the final sealant layer were tested:
- Winsor and Newton UV Gloss Varnish
- 10% Paraloid B-72 in acetone
The latter was chosen because it is not water-based and therefore did not disturb the Gum Arabic adhesive. It also has excellent ageing properties and should not disrupt the effect of the gold.
Treatment Evaluation
This treatment required much creativity and trial and error. It was a priority to keep the treatment as “natural” (e.g. organic but not animal-based) as possible, however, this was not done where it meant sacrificing the overall safety of the object.
Many materials needed to be tested and layered to determine what would achieve the best final result, especially given that there were no previous treatments of the same style on which to base it.
The final result was everything that I hoped for the treatment. The object is stable and has lustrous gold joins which really highlight the beautiful shape and history of the object. Although the final mount could not be made completely invisible, as was the hope of the owner, it is not visually obstructive (lined with black velvet) and should provide some peace of mind about its long-term display.
