Conservation of a pair of candlestands

Title: A pair of Candlestands

Acc. Or Loan No.:  66.64.9 & 66.64.10

Provenance and/or date: British, ca.  1755-1760

Medium: Mahogany

Dimensions: Height (66.64.9): 51 3/8 in. (130.5 cm)

                      Height(66.64.10): 51 1/2 in. (130.8 cm)

Conservation Intern: Yang Xu

Supervisor: Mecka Baumeister, Conservator, Objects Conservation

Curator: Wolf Buchard, Associate Curator of European Sculpture and Decorative Arts

Sampling and/or analytical results: X-ray radiography 10.30-31.2019        

Description AND HISTORICAL BACKGROUND

This pair of candlestands is in the style of Chippendale in Chinese taste. It is believed that the pattern of the candlestands is originated from the candlestand B on Plate CXX in Thomas Chippendale’s celebrated pattern book, The Gentleman and Cabinet-maker's Director, with modifications of the carving on the base and the fretwork of the gallery on the top. Plate CXX published in the 1754 and 1755 editions, but not reprinted in the 1762 edition. The description of this pattern in plate CXX is “…the stand B is composed of fretwork; three of those are to be glued together to make the whole compleat…” The fretwork of the gallery may be an elaboration upon one pattern in plate CLI (plate CXCII in the 1762 edition). The actual dimensions of the candlestands are in scale of the design from the book.

The candlestands are made of mahogany. The fretwork shafts of the body are laminated with three layers of wood in cross-grain directions, showing a vertical grain direction on the outer layers. The tops are hexagonal in shape with fretwork galleries made of a cross-grain laminated structure, showing a horizontal grain direction on the outer layers. “Each shaft of the pair of candlestands consists of three sections of geometrical fretwork, joined along the center edges with glue as described in Chippendale’s Directory and ends in tripod bases. The bases have cabriole legs, while the decorations diverged from the design in the pattern book. The legs are decorated with a pattern of scrolls and interlacing bands, which enclose an area at the knees of faceted lozenges. The pad feet are decorated with scrolls centering on a rosette”[1].

[1] ESDA files, 66.64.9&10, The Metropolitan Museum of Art.

Condition

Previous Treatments

Conservation records include a copy of a 1971 Request for Treatment for candlestand 66.64.9 from James Parker, curator of Western European Arts. It records that on May 20, 1971, the candlestands were treated by John Canonico: “Gallery restored - Missing sections made up in balsa due to the fragility of the section. Patination aniline and shellac”. The exact sites of this restoration campaign on the object could not be located.

There are two metal brackets attached to each of the candlestands from earlier undocumented repairs, screwed to the underside of the middle two central joints of the fretwork shafts to stabilize the structure.

There is excess of glue present along several joints of the gallery sections including the grooves in the bottom of the tops on both candlestands, indicating the sections were reglued, most likely with white glue / PVA glue. At least one gallery section on candlestand 66.64.9 and two or more on candlestand 66.64.10 were restored/replaced. These gallery sections are veneered on both sides, not laminated as the originals using three layers of the same thickness. The wood of substrate can’t be identified. And their mahogany surfaces are more open grained and the finish is thin and flaking.

The tops are attached with screws inserted from the underside of the supporting round plates. These supports are screwed into the top of the fretwork shafts. The screws are all modern as confirmed by X-ray radiographs. Screw holes in the plates and underside of the tops indicate that the tops were rotated more than once in the past, 60° or 120°.

One of the legs on section C of candlestand 66.64.10 was broken and rejoined. The joint can be seen from the side and underside of the leg. Most likely during the incident when the leg broke the entire candlestand crashed, which also severely damaged fretwork section C of the shaft. The restoration may have resulted in the distortion of the fretwork shaft and the tilting of the candlestand.

For the label system of section A, section B and section C, please CLICK HERE.

Construction

The supporting round plates are screwed into the top of the fretwork shafts using one screw for each each joint, there are three joints at each fretwork section of the shaft. Then the tops are screwed into the supporting round plates from the underside with three screws for each candlestand. The X-ray radiographs indicate that there is no other joinery between the tops and the fretwork shafts, besides the screws.

The three fretwork sections of the shafts are glued together along their center edges. No nails, screws or other joinery were found during X-ray radiography except the later added metal brackets.

The cabriole legs are dovetailed into the bases. Extensions of the three fretwork sections forming the shaft of each candlestand are inserted into mortises cut into the bases.

For candlestand 66.64.9, the X-radiographs of the base revealed the joinery. The fretwork shaft is tightly joined with the base and the depth of the mortises does not interfere with the dovetails of the legs. For candlestand 66.64.10, the X-radiographs of the base revealed evidence of the earlier mentioned restoration. The mortises for the extensions of all three fretwork sections were cut deeper into the base during this campaign, intersecting with the dovetailed joints of all three legs. They were probably joined/filled with glue, but can’t be identified from the X-radiographs. The extensions of the laminated fretwork shafts appear to float in the enlarged mortises and to be only secured in place with glue.

The cross-grain laminated structure of the three fretwork sections forming the shaft of each candlestand and the gallery sections of the tops are visible at their exposed edges and in the radiographs. The bottoms of the tops and the bases are made of solid mahogany, not laminated. The mitered gallery sections are glue-joined and reinforced with splines in the upper section of the corners. The gallery is placed and glued into grooves cut into the bottoms of the tops.

Surfaces

The pair of candlestands shows inconsistency in color and finishes. Candlestand 66.64.9 is generally brownish in color, and a clear coating covers the mahogany wood, with dark staining or paint in some areas? of the surface. The clear coating is degraded and became yellowish and hazy. Candlestand 66.64.10 is reddish in color, more saturated and glossy compared to the other one.

UV photography was conducted to document the condition of the surfaces. Under UV light, the candlestand 66.64.10 shows overall an orange fluorescence, indicating that it was completely refinished with shellac. The candlestand 66.64.9 seems to be refinished with a non-fluorescent brownish/dark coating or pigmented wax finish, and only shows a greenish yellow fluorescence partially on the edges or corners, where the surface coating was abraded. The excessive glue residue, mainly along treated joints a during past restoration, shows a strong pale blue fluorescence under UV light, and is aesthetically disturbing.

The top of the candlestand 66.64.9 shows pale blueish fluorescence under UV light, which also shows on the outside of the gallery sections on the top of the candlestand 66.64.10. It is unclear whether the pale blueish fluorescence is from the same finish as the rest of the candlestand 66.64.9 or a later refinish campaign, as well as the outside of the gallery sections of the top of the other candlestand. The orange fluorescence on the surface of top tray of the candlestand 66.64.10 shows on the lower part of the inside of the gallery sections as well, which may indicate the refinishing with shellac were only focused on the top surface of the tray. The top of the candlestand 66.64.9 shows several spots of orange fluorescence under UV light, likely to be a later retouching with shellac.

Condition issues

Candlestand 66.64.9 is overall in good condition. The main issues are, that the central joints of the three fretwork sections forming the shaft are loose, loss of laminated sections on the gallery of the top, delaminated structure of the fretwork sections of the shaft and gallery sections on the top, and white glue residue along the joints.

Three central joints of the fretwork shaft are detached due to glue failure and wood deformation, leaving gaps between the components. Two of them are stabilized with metal brackets during a previous treatment.

Delamination mainly occurred in the gallery sections of the top. The thin fragile pieces can easily be detached and broken. There is one large loss in the exterior layer of the gallery fretwork, and several small losses in the same section. The areas of the losses display in the UV photographs a strong pale bluish fluorescence of the exposed glue layer.

The clear surface coating degraded and turned yellow. A pigmented wax or paint/stain layer which appears to be applied on top of it is blanching and abraded. There are losses of the surface finish (pigmented wax, or paint/stain) overall, especially on the gallery sections of the top.

Candlestand 66.64.10 is in fair condition. Its entire structure is tilted caused by the rejoined broken leg and deformation of the fretwork shaft. The structure is unstable due to the loose or detached central joints. As mentioned above, section C of the fretwork shaft has been damaged and restored. There are cracks and losses in the wood layers mainly in the middle part of the fretwork shaft.

Three pieces of the gallery sections on the top are misaligned, due to a poorly executed previous restoration. There is excess of white glue along the joints and underneath the gallery sections in the grooves. There are also gaps between the joints of the gallery sections.

Wax deposits are present in recessed areas, especially in the gallery fretwork and carvings on the legs, while the surface finish is still intact.

Treatment

• Solubility/cleaning test with DI water, mineral spirit (Shellsol® D70 , aroma free), acetone, and ethanol

The test results showed that both DI water and mineral spirit picked up dirt and grime on the surfaces, mineral spirit disturbed the wax deposits on the surface, while acetone and ethanol removed all the dirt and surface layers (distinguishable by their UV fluorescence), leaving the bare wood exposed.

The later wax polish present on the surfaces of both candlestands, especially on the galleries of the tops, covering the earlier finish (if still extant), showed thick deposits in recessed areas of the exquisite fretwork and carvings, which developed blanching over time. The patination with aniline stain mentioned in the above listed conservation report is present below the wax layer.

• Surface cleaning with mineral spirit and dry/mechanical removal of wax deposits

Dusting and vacuuming.

Swabs with Shellsol® D 70 were used to gently clean the surfaces, reducing the dirt embedded in the wax coating and grime deposition.

Mechanically scraping with scalpel blades/bamboo sticks was carefully conducted to remove the waxy deposits and reveal the edges of the gallery’s fretwork of the tops and details of the carving on the legs of both candlestands.

• Consolidation of the damaged shafts and making wood fills for the losses.

On candlestand 66.64.10, several severely damaged areas (mainly on section C) of the delaminated wood layers of the shaft’s fretwork sections were reglued with cold setting fish glue and clamped to apply pressure. Small losses and gaps were filled with mahogany, glued and clamped in place.

• Structural reinforcement of loose joints: the gaps were filled with wood shims, using custom-made jigs for the gluing and clamping process.

The three central joints of the shaft of candlestand 66.64.9 are disconnected and almost all of the central joints on candlestand 66.64.10 are loose and detached. During a previous restoration two metal brackets were screwed to the underside of two major joints on both candlestands to stabilize the structure. Due to the loose central joints and deformation of the shafts’ fretwork sections on both candlestands, it’s impossible to close the gaps between the joints. The metal brackets also limit the movement of the components. Therefore, mahogany shims were cut to the required thickness and inserted into the open joints of the three fretwork sections forming the shafts. Then each joint was glued together with cold setting fish glue. For the clamping and gluing process of the loose joints, wood jigs covered with Volara were made to provide the proper directional force. Since the space is quite limited for the positioning of clamps, dry clamping was performed first and jigs were cut to different sizes and shapes to accommodate the clamps. Wooden blocks were also inserted as spacers to protect the thin sections of the fretwork during clamping.

After the glue set, excessive glue was removed with damp swabs. Each fill was associated with one particular fretwork element of the shaft, and shaped accordingly with chisels to the correct shape.

The tilted structure of candlestand 66.64.10 was corrected with the display mount, which is non-invasively attached to its base and legs and fastens the candlestand to the gallery wall. The mounts are made of brass by Andy Estep and Johnny Coast, conservation preparators in OCD. The mount supports and raises the restored broken leg (section C, below the caster) thus correcting the tilt.

• Consolidation and loss compensation of the delaminated gallery sections of the top of candlestand 66.64.9

Several delaminated sections of the three-layered mahogany gallery were reglued with cold setting fish glue and clamped.

After the mock-up in the British galleries on Dec. 12, 2019, the decision was made to fill the large loss in the fretwork of a gallery section on candlestand 66.64.9 to improve the aesthetic appearance.

Low tack tape was used to trace the shape of the loss. A piece of mahogany veneer was cut to the traced shape with a fretsaw, toned to a matching color with acrylic paint, and glued and clamped to the gallery section. After the glue was set, the piece was trimmed to the exact shape. Smaller losses were also filled with mahogany veneer using the same method. Some distractive cracks and dents were filled with Modostuc (mixed with 40-50% fish glue for better adhesion and strength). After they set, these fills were shaped with a scalpel and polished with damp tissue paper.

• Reversing old repairs and realigning the galleries of the top of candlestand 66.64.10, loss compensation with mahogany wood and PC Woody epoxy resin

The top of candlestand (66.64.10) was heavily restored. White glue excess was present underneath at least three pieces of the gallery, which were also misaligned. Between one of the gallery sections and the bottom of the top was a big gap due to the movement of the wood, loss of wooden material and poorly excecuted restoration. The gap provided access to remove old repairs and realign the gallery sections. A scalpel blade dampened with acetone was inserted into the gap to break the PVA white glue bond, taking the gallery apart. The groove cut into the bottom of the top, housing the gallery section, was cleaned with Laponite RD (5% in deionized water) to remove all remaining glue for realigning the gallery sections.

Removable PC Woody fills were cast to fill the gap between the groove and the underside of the gallery section using a Parafilm barrier in order to realign the gallery section and fill the loss in the molded edge of the bottom. After the fills had set, they were shaped with chisels.

Mahogany veneer fills were made and glued in place to compensate losses in the fretwork of the gallery sections and gaps between their joints. The removed gallery section was first spot glued to the PC Woody fills, and then spot glued to the bottom and the adjacent galleries prior to clamping.

• Reversing old repairs on the fretwork of one gallery section on the top of candlestand 66.64.10 and stabilization.

The gallery section on the proper left side (in the display position) of the top of candlestand 66.64.10 was poorly restored. In the proper lower left part of the fretwork of this section only the middle layer remained and was heavily damaged. The adjacent delaminated section of the gallery was misaligned and damaged with a small piece of wood repair misplaced. In order to stabilize and secure the severely damaged structure, the old repairs were reversed with Laponite RD (5% in deionized water) and the glue residue was removed. A fill made out of mahogany veneer was glued to the fretwork to complete the surface and add a supporting layer. Several additional wood fills were made and glued in place to compensate losses in the gallery sections. In addition all delaminated and loose layers were reglued and stabilized.

• Surface treatment

For the tiny losses of the finish on both tops of the candlestands, watercolor was used for retouching. Dilute Artcolle fish glue was used first to seal the exposed surface areas and to match the gloss of the adjacent surface finish after inpainting.

The steps were: first applying one or more layers of dilute glue (water:glue 1:1 or 1:2 depending on the required layer thickness) with a brush to fill in the loss. Then watercolor was mixed with diluted glue (1:1) to match the color and applied very dry to the glue layer without dissolving it. Depending on the thickness and gloss of the adjacent surface layer, another glue layer was added to build up thickness and gloss. The surface was buffed with tissue paper or rubbed with a finger in case the gloss needed to be reduced.

The mahogany shims inserted into the central joints of the fretwork shafts were also inpainted in this way.

Other fills were inpainted with several thin applications of diluted acrylic paints to achieve the correct color match.

Larger finish losses and fills were coated with Golden MSA varnish (thinned with MSA solvent) matching the gloss of the adjacent surface. Due to the extant glossy surface finish and open wood grain of the new fills, multiple applications of varnish were required. To build up the proper thickness and fill the open grain, the applied varnish layers were smoothened between each application with Micromesh (6000/8000 grit).

Remaining blanched areas of the wax coating and areas of damaged surface finish with a rough texture were saturated with Golden MSA varnish (thinned with MSA solvent).

The bases showed slight haze due to the degraded wax layers. Shellsol® D 70 was used to reduce the wax overall. Then a Leister air gun with controllable heat setting was tested to soften the wax finish at the lowest temperature, while using cotton swab to buff the surface. For candlestand 66.64.10, the heat treatment worked well to regenerate and even out the wax finish which became clear after buffing. For 66.64.9, direct buffing with cotton swab could reach the same result as buffing in combination with heat. Considering the potential damage to the original finish underneath the wax layers by exposure to heat, direct buffing with cotton wool was adopted to treat the surfaces of the bases of both candlestands.

Overall the surface finish was improved by dirt removal, retouching and adjusting the wax finish by buffing and where necessary locally applying a thin layer using Golden MSA varnish (thinned with MSA solvent)

Final adjustments and retouching were performed in the British galleries after they were properly lit lit by the light designers.

Opening Night