Decorative Metal Figure

CASE STUDY

The figure's arm had been previously reattached at an awkward angle, and needed to be corrected to better match the artist's intent.

 

BEFORE TREATMENT 

Scripps College, 2983

THE OBJECT

The object is a small metal figurine of a boy dancing, mounted on top of a cubic wooden pedestal with a sloping front side. The pedestal is undoubtedly a later addition, as the figure was likely part of a larger decorative object, such as a gas table lamp. The figure is cherub-like with a shoulder-length Greco-Roman hairstyle. He appears nude with a flowing scrap of material tied around his waist. Provenance and cultural attribution unknown. 

MATERIALS

Bulk Materials

A file abrasion on the outside of the figure’s proper left hip revealed a layered structure. X-ray fluorescence spectroscopy (XRF) of the interior grey metal (red) showed high peaks for lead, zinc and copper, while the outer metal (blue) is predominantly copper with traces of vanadium, iron, nickel, and antimony. 

Surface Materials

Visual analysis distinguished a homogenous, fine-grained, bright gold layer over the copper, covered by a layer of dark resin or wax (which may have been lighter in the past) that contains a coarser, golden metallic powder. The copper-rich substrate interfered with an accurate analysis of the surface decoration by XRF, however, spectra showed a distinct peak for zinc in the decoration which is absent from the bare copper substrate. The presence of zinc may suggest the use of brass powder, commonly employed in this manner to give a metallic gold-bronze look.

FABRICATION

In x-rays, the arms appear solid while the head, torso and legs are hollow or semi-hollow. There may be remnants of an armature or support in one leg. Due to the simplistic elements and lack of detail or undercuts on the sculpture, it was likely sand cast. This is supported by visible joins and seams that suggest it was cast in separate pieces using a piece-mold process.

The exact method of fabrication was undetermined, but one theory is the figure was cast in copper with lead poured inside to coat the interior. Or possibly the figure was electroplated: cast in lead with copper electrolytically deposited over the surface. Also, a model of the figure could have been made in plaster (the model responsible for the seams), covered in graphite, and then electroplated with copper until it built up to a structural thickness. Lead may have been poured in the interior for added strength, and last, the surface gilded in gold. 

 
 

λ ExcMax = 300 - 400 nm

λ Em = 400 - ~750 nm

Microchemical tests of samples taken from the dark resin layer tested positive for rosin and carbohydrates using the Raspail test and the triphenyltetrazolium chloride test. UV-induced visible fluorescence showed coated areas—likely the aged binder (dark resin) holding the metallic powder—fluorescing a distinct pale orange color. This fluorescence may suggest a thinned shellac or beeswax. It’s also believed the figure received a wax coating for aesthetic improvement, as a thin waxy film could be pushed around on the surface by gently prodding with a bamboo skewer.

 

Solubility tests indicated the lower campaign of bright, fine gold was insoluble in water, acetone, ethanol, and mineral spirits, however the top layer of dark resin was soluble (or ss) in everything but water.

CONDITION

Structurally the figure was stable and secure on the wooden pedestal. X-ray radiography showed two nails and a screw mounting the figure to the pedestal, which may have been paired with some adhesive as well.

There was significant loss of both layers of gold/metallic surface decoration—particularly worn off at high areas on the statue. This left a majority of the copper substrate bare and oxidized. The top layer of dark resin with metallic powder was especially fragile in areas and detaching from the surface.

The most notable condition issue was a previous repair’s awkward placement of the figure’s proper right arm. The arm angled backwards, joined by a ¼” wide area of welding material.

BEFORE TREATMENT 

Analysis showed the welding material at the arm to be a Pb-Sn solder, chemically matching an area of solder under the figure’s proper left hand, which may have once attached an element that is no longer present. This lead solder was differentiated from the lead within the figure by the presence of tin and the absence of zinc.

 

TREATMENT

Treatment focused on light cleaning, stabilization of detaching areas of the surface decoration, and correcting the position of the figure’s arm. Though it was desirable to remove the figure from the unoriginal wooden pedestal, it was clear that attempting to do so would not be possible without damaging the pedestal, and time also did not permit pursuing its removal.

Cleaning & Consolidation

There was a great deal of grey dust and dirt on the figure, especially within recesses. Loose debris was removed using a soft bristle brush and an air-puffer balloon, and deionized water on cotton swabs was used to clean stable areas of the surface. Flaking areas required stabilization, and solubility tests indicated that only an aqueous consolidant would be safe. Aquazol 200 was chosen and used at 10% w/v in deionized water to consolidate unstable areas of the surface decoration.

The Arm

It was deemed most safe and controllable to cut through the Pb-Sn solder using a jeweler’s saw with a No. 460s spiral blade. Surfaces around the solder join were wrapped and protected with Ethafoam, and the wooden base of the object was clamped to the work bench for stability while cutting. After removing the arm, excess solder was mechanically removed from both join surfaces using a scalpel. This revealed the hole to the figure’s torso cavity.

A small hole was drilled into the join area of the arm to accommodate a 3mm wide metal peg (Type 304 stainless steel). The peg was centered and secured in the hole using Araldite liquid epoxy bulked with glass microballoons. Next, over a barrier layer of 40% Acryloid B-48N in acetone, an epoxy putty “plug” was sculpted around the metal peg using FIXIT Sculpt, designed to fit the cavity in the torso.

DURING TREATMENT 

Without any available references or context for the object, the position of the arm was determined using the downward sloping angle of the figure’s shoulder. The arm was attached to the figure using 40% Acryloid B-48N in acetone, and the same resin was used to create a barrier over surfaces that would receive fill material. FIXIT was used again to fill the join space until it was flush with the surface.

Last, the area was visual integrated using gouache colors in water.

Materials & Suppliers

Aquazol 200—Poly(2-ethyl-2-oxazoline), C5H9OH

Talas

20 West 20th St.

New York, NY 10011

USA

 

Acryloid B-48N—methyl methacrylate copolymer

Conservation Resources Ltd.

Unit 2, Ashville Way

Off Watlington Road

Cowley, Oxford OX4 6TU

England

 

Araldite AY103/AY956 epoxy resin/hardener—modified aliphatic polamine (AD09)

Conservation Resources

5532 Port Royal Road

Springfield, Virginia 22151

USA

 

Glass Microballoons—GB03 0.34 - 0.40

Conservation Resources International, LLC

5532 Port Royal Road

Springfield, Virginia 22151

USA

 

FIXIT Sculpt—multimedia repair compound

AVES

P.O. Box 344

River Falls, WI 54022

USA

Holbein Artists’ Gouache

Holbein Works, Ltd.

Conforms to ASTM D 4236

 

Windsor & Newton Designer Gouache

London, England

Conforms to ASTM D 4236

 
 
 

AFTER TREATMENT 

Scripps College, 2983

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