The fills were made by mixing the epoxy resin used for bonding with fumed silica to make a paste suitable for spatula application. This paste was then tinted with dry powder pigments to match the original colours.

By building up the layers of the porcelain colour and managing their translucency I was able to recreate an approximate tone to the original.

The fills were then polished with Micromesh® to give them a sheen; however, though they blend in, they are still discernible to the naked eye.

After that I applied thin lines of Golden® gold acrylic paint to both sides to reinstate the gilded decoration. And guess what, challenge solved! Here are some detailed pictures. Thank you for reading!

Uff!…

]]> http://westdeanconservation.com/2012/05/17/meissen-pierced-dish-challenge-solved/feed/ 0 final b cestreito paste paste paste polish polish fills fills fills final b final ab http://westdeanconservation.com/2012/05/15/recent-press/ http://westdeanconservation.com/2012/05/15/recent-press/#comments Tue, 15 May 2012 21:31:01 +0000 Abigail Uhteg http://westdeanconservation.com/?p=626 Read more]]>

When this article in The Independent came out, featuring Brittany Cox (MA Conservation ’12) and Metals Programme Tutor Jon Privet talking about conservation courses at West Dean, we thought it would be nice to a press round-up (well, we thought it would be nice to show off). Here is a smattering of things published by or about—or inspired by—West Dean students and faculty over the last academic year:

Miriam Chance (PGDip Ceramics ’11) on ceramics conservation at West Dean: Ceramic Review Magazine, September/October 2011

Tristram Bainbridge (Assistant Tutor in Furniture, MA Conservation ’11) on how to safely clean furniture & wooden objects: Furniture & Cabinetmaking, March 2012. Also in the same issue, an article by Furniture Programme Tutor Norbert Gutowski about Martin Spencer, a student in furniture making this year.

Me (Abigail Uhteg, MA Conservation ’12) on studying book conservation at West Dean in the last issue of the  Bonefolder, volume 8 2012. I wrote a review of the recently-published Paper and Water in the same issue. The full text is available for free at the website.

And for something more unusual—Clocks Programme Leader Matthew Reed’s conservation of a silver swan for the Bowes Museum inspired Peter Carey’s new novel The Chemistry of Tears. It’s had a lot of press already over the last few years, and Matthew gives a great talk about it, but we think this is a pretty great new spin. (Photo by Brittany Cox.)

One of the projects he has at the bench right now

Mixing Paraloid-B72 on a lathe!

Making a frame from scratch

And testing out a new espresso machine at afternoon tea

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Before treatment.

The mid-19^th century family Bible that I am currently working on with William, one of my fellow students, has many interesting challenges for conservation.

It is a large, heavy volume (270 x 340 x 95 mm), sewn on five recessed cords. Usually, the sewing on recessed cords is not so strong as, for example the same book sewn on raised cords, but surprisingly the structure of this spine is still stable.

The boards on both sides have been completely detached from the spine (one of common issues of old books). They are each constructed of two laminated pieces of board, which are separating at the corners.

The brown calfskin covering the volume has been heavily deteriorated and shows the characteristic orange red powdery texture of “red rot”, the acidic deterioration of leather, observed on leathers especially from the mid-19^th century. The distinguishing smell, which is the same as the one I often smell in second-hand bookshops or libraries with old books, was also confirmed from this red-rotted leather.

In order to carry out the conservation work, first of all, it was necessary to stop the calfskin from being powdery by using a consolidant. Klucel-G, a weak adhesive, was dissolved in isopropanol and applied to stick back together the crumbled leather on the surface. The back sides of detached leather pieces were also coated with Klucel-G. These detached leather pieces were pasted back using wheat starch paste after the boards were re-laminated. For this step, quite a large amount of wheat starch paste was needed, and it contains a lot of moisture, which often leaves black stains on degraded surfaces of leather. The Klucel-G coating on the back of the leather would protect the moisture from staining the leather.

Delaminated board.

Squishing wheat starch paste between delaminated board layers.

Once the leather was treated, William and I started working on the four pieces of metal furniture. They are two pairs of clasps set on the corners. Two on the front board were still firmly attached, but one on the back board has been detached and the other one has been very loose.

After consulting people in the Metals Department, the green copper alloy corrosion was scraped off with a scalpel under a microscope. Particularly under the microscope, the corrosion’s bright green colour was very beautiful next to the copper alloy’s gold colour, so I kind of wanted to keep them. But instead of keeping it on the furniture, because it would continue to corrode and cause damage, we collected and analyzed it with the FT-IR spectrometer.

Furniture before cleaning.

Furniture after cleaning.

We used these samples as excuses to try out this kind of spectroscopy. Actually, (as you may know) FT-IR works better for organic materials rather than inorganic materials, like this copper corrosion. However, the spectrum we got was totally different from any of the reference spectra of verdigris (copper corrosion) provided on the Infrared and Raman Users Group website, a resource with FT-IR spectra. We could have analyzed it with XRF, but when we figured that out, we didn’t have enough verdigris left to study. It was a learning experience.

Preparing the verdigris for FT-IR analysis.

Although the verdigris analysis with FT-IR failed, the analysis of the transparent brown substance on one of the furniture was successful: it was defined as mastic, a kind of resin. Also, the metal of the furniture is now identified as brass, as the XRF spectrum showed peaks at copper and zinc. The conservation project on this Bible demonstrates very well that scientific analysis helps us to obtain more precise information on the material we work.

We will go on to the cleaning of the brass furniture with IMS followed by a protective coating of microcrystalline wax, as well as repairing the hinges. Once the furniture is ready, it will be reattached on the board with new nails.

The tube hollow on the spine has already been removed for rebacking and board reattachment. The boards will be slotted to attach new hinges for reattachment to the spine. Then the spine will be given a new hollow, covered by the new leather, and the original spine leather will be pasted on to that. Every bit and piece will be assembled soon – please look forward to the next post!

Cleaning of the spine by poulticing with sodium carboxymethylcellulose. The original mull, a lining material, is still firmly attached.

Alex Brooks consolidating the disbound leaves of a 16th century printed book using Klucel-G in isopropanol

Alex Brooks and Brittany Cox figuring out a papier-mâché fill for a papier-mâché head on her automaton

Leather dyeing samples in a lecture from David Dorning

Abigail Uhteg analyzing the pigments on a 17th c. Italian manuscript using XRF spectroscopy

The Scarlet Tanager is an American songbird, which belongs to the cardinal family and is largely known for its vermilion red plumage and carbon black tail and wings. Attempting to identify the old relative at my desk in the Speelklok Museum workshop proved quite challenging. Radcliffe, as I named him, was faded, dusty, and the light in his once bright eyes had dimmed with age. He no longer resembled his vibrant cousins. After sending a chapter of the Audubon Society some images, I was thrilled to learn his true identity and imagined him singing in the lush canopies of South America. What a strange thing, to outlive and out sing all others of his species, for as a mechanized bird he will go on singing for decades to come.

Repairing Radcliffe was no easy feat. Among the various faults in the mechanism, a section of the clockwork for commencing and ceasing the performance was missing and the bellows for voicing Radcliffe needed recovering.

I ordered Zephyr, a fine parchment-like sheet of pressed goat intestine used for pneumatics, to recover the bellows. Usually a pattern is made from the material originally covering the bellows, but if this is missing one can make a pattern by hand through measuring the separate bellows chambers. PVA is a decent adhesive to use for applying the material, but it has the tendency to creep over time and will eventually allow air leaks. ‘Titebond’ may be a more suitable adhesive, as it possesses rubber-like properties without the off-gassing you get with rubber products, such as ‘Evo-stik’, which is known to cause metal corrosion.

The paper valves, allowing and restricting the internal air flow between the bellows chambers, also needed replacing. The most common issue with bellows is the valve system. Traditional paper valves are faulty and deform with moisture, making their lifespan quite brief. I found using a brass and plasticine system is the most effective and fool-proof method.

Once the bellows were recovered and the valves replaced, there were a few other issues to sort out. The valve for the brass slide whistle was leaking and needed to be polished flat, and made airtight. After this was resolved, the bellows were so efficient they no longer needed frequent pumping to fill. The rate of the bellow pump lever was too fast and a method had to be devised for slowing it down, or transferring some of the energy. A set of small links were made and tested until the correct size and shape was found.

Radcliffe at one time possessed the element of surprise. Many singing birds were made so that when the performance ended, it would restart for short intervals almost at random, strengthening the illusion of a living bird. This part of his mechanism was missing and had to be made again.

The bellows serve as part of the magic. The reservoir will begin to empty once full, due to a spring that keeps tension on the chamber. As it collapses, it releases a lever that sets the mechanism back into motion, making the bird sing again.

There was one other matter to sort out before Radcliffe was ready for his performance. He had lost his tail feathers over the years, so I made him a sort of toupée…

Using similar feathers and brass paper clips, I made a little ‘clip on’ tail that can be easily applied or removed without damaging his fragile body.

There was a time when Radcliffe sang just for me; now he is singing for all of you:

Before treatment

Terracotta is a type of soft red clay commonly used for its plasticity and ability to take detailed decoration motifs. Examples of its use throughout history are abundant and a lot have survived until the present day. However small and incredibly well preserved (considering its possible old age), an object like this can tell us about the habits and beliefs of a civilization of other times.

Excavated in Great Henny, near Colchester (Suffolk), a well-known Roman settlement in the UK, we could easily attribute its making to that empire. However, in-depth research must be done prior to those affirmations. If Roman or even brought to England at that time, these figurines were commonly made as votive objects in homes or temples. It is a draped sitting female figure with head decoration and her arms close to the body suggesting a pudicitia, representation of modesty during the Roman Empire.

Mould joint line

The object was made as a small hollow moulded figurine by a technique where the clay would have been pressed to a double-sided mould and then joined together. This making process can be proved by the visible joint line where the two-part mould would have met—the maker’s fingerprints were preserved on this line and also on the inside. A white slip was then applied and possibly colour decoration too (minute pink and black evidence of this was found).Upon acceptance the figurine showed extensive dirt accumulation due previous burials and a noticeable previous repair. I tested the aged and brittle adhesive for solubility and found out that it softened in acetone. Dirt was brushed away and, when too compacted, a moist swab was used for easier removal. Due to the decoration’s fragile state I tried to keep moisture application to a minimum.

For the dismantling process the figurine was padded with acid-free paper and placed in a sealed container with a solvent reservoir with acetone. The solvent fumes softened the adhesive enough so that the sections could be securely dismantled. This process was monitored regularly to assess any alteration on the slip layer. When in separated sections, I softened the adhesive residues with acetone and mechanically removed them as shown on the pictures.

Process of removing old adhesive residues

After the sections were bonded with Paraloid B-72 in acetone (35%) a support fill was added to the base area. The same adhesive used for bonding was bulked with glass microspheres to make a removable fill. The area was sealed with aluminium foil and a dental wax mould was put in place as a support. The microspheres paste was then applied and let to dry. By doing a fill in this way I  could then safely shape and sand it far away from the original. After completely dried, the fill was skimmed with fine calcium carbonate putty and attached to the figurine with the same adhesive.

Wax mould supporting fill on base

More than just preserving material aspects, I also tried to improve its appearance. If the figurine belonged to a museum the aim would have been to only to stabilize it mechanically and chemically, usually for research and display purposes. However, when an archaeological piece belongs to a private collector like this one, conservators need to “think outside the box”. In a museum, glass air-controlled showcases will prevent dust accumulation and unnecessary handling; on the other hand, on the shelf near the family photos, it becomes a decorative object in a mixed environment.

Therefore, I put in smaller fills of the small chips and losses that were big enough to catch dirt or a passing sleeve aiming for a book on the top shelf. After soft polishing with soft abrasive papers, the fills were retouched with acrylic paints to match the fills’ surrounding clay colour.

Before and anfter retouching fills

 After completion of the treatment the figurine can safely go home with only a few recommendations on how to be taken care of (i.e. dust clean) for its maximal safety over a long period of time.

This Boulle object is almost identical to another object seen in Antique Boxes Tea Caddies, & Society; it has been confirmed that both of these objects originate from the same period and location and utilise the same techniques. Due to these factors I have been able to allude to published excerpts with a high degree of retained verisimilitude in creating a context for this object’s commission and completion by a master craftsman.

Description of the Object

The object is a box (height 145 mm, width 327 mm, depth 258 mm) with the following materials: solid poplar, ebonised veneer and covered with a “contre-partie” Boulle-work of red turtleshell in a background of brass; which carries a central design. The ‘body’ of the object can be described as ‘typical’ of 18^th century work; it utilises bold swirls, curls and floral designs. A similar description serves for its twin object: “The pattern is in bold swirls forming floral designs and cusps, typical for 18th century work.” [1]

In addition to its carved feet, this Boulle object clearly depicts a Satyr-like ‘faun’ and a dancing woman clutching a tambourine. The use of a central ‘panel’ design is adopted by the next generation of furniture makers:

“…One of the main exponents of this genre of design was Jean Bérain, whose ‘Arabesques’ foreshadowed the Rococo period in France. Like on this box, Jean Bérain placed his figures in the centre of elaborately fantastical compositions.”

Because of this, the object can be considered as part of a very well-defined evolution of objects.

The Context of the Central Panel

The use of a ‘Dancing Girl’ and a ‘Woodland Man’ is an interesting allusion; it allows us to explore the historical and social context of the object.

‘This style of decoration, which was inspired from ancient Rome through the Italian Renaissance, became popular in France during the second half of the 17th century, by the advanced technique that André Charles Boulle (1642-1732) used for the refined objects which he delivered among others to the royal family of Louis XIV.”

The classical period styles the authors reference were likely influenced by the ‘grand tours’ of 1700-1796. A gentlemen went abroad and admired the marbles, had an adventure with the local wine (and women), then returned home keen to show off his well-travelled scholarship of Objects d’Art.

This object references this desire, but in quite a ‘tame’ way. From a research point of view, one can say this is a ‘classical allusion’ and a ‘bowlderized image’, not a serious attempt to recreate a specific piece of Art. Several key things about this scene would alarm an art historian.

Firstly, the tambourine is an anachronism.

Secondly, both these figures are wearing clothes. If this was a copy of a Roman scene, the woman would be nude. If it was Greece, the reverse would be true. If this was a French piece from post-1796, one or both of the woman’s breasts would be exposed. Analysis of this composite piece (and the knowledge of when/where Boulle technique developed) allows for an accurate date to be calculated: circa. 1770.

I will be updating this blog as I conserve and restore this box. I will also be commenting on ethical issues such as replacing turtleshell with a synthetic imitation. It also gives me the opportunity to conserve silk, which is something I have never done before. You can find a link to my website here.

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[1] Antigone Clarke & Joseph O’Kelly’s, 2003 Schiffer Publishing Lto. Antique Boxes, Tea Caddies, & Society, Chapter 10 “Boulle or Buhl”, page 109.

An interesting project came to the Books department last week: Brittany made this beautiful silver case for a tiny automaton, and the client asked for it to be covered in shagreen. We use a lot of different skins on a regular basis, but this one is unusual:

Shagreen is a bit of a loose term for a range of rough-textured skins. The 17th century Persians made it by pressing pebbles or seeds into horse, camel, or donkey skin to give them a bumpy grain; since then it has been used for a variety of coarse-grained skins. Now it most frequently refers to the skins of rays as well as (less frequently) sharks, dogfish, and other cartilaginous fish. These are covered in protrusions called placoid scales; they’re very similar to teeth, with an inner core of pulp surrounded by dentine-like material and a thinner layer of enamel-like material. In Japan shagreen was used (undyed) for sword handles and armor, and in China for bows, in both instances its texture offered the user a better grip. In Europe for a long time it was simply an inexpensive byproduct of the fishing industry, used for abrasive: check out the description of making this modern shagreen sanding block.

Though it had been imported to Europe for about a century already, in mid-18th century Paris Jacques Galuchat popularized green vegetable-dyed shagreen when he covered hundreds of small objects for Louis XV and Madame de Pompadour. The material experienced a renewal in the 1920s on Art Deco furniture and small objects, often either green or undyed. The skins are small to begin with, and the useable parts even smaller, so it tends to be used to cover only small items, or in multiple panels if on furniture: there are some nice photos here.

Shagreen is prepared by scraping, stretching, and drying the skin rather than tanning or tawing it. When used for decoration rather than grip, the dermal denticles are usually sanded down flat, as in the skin above. This one is an adult ray from Ed Tanner in London. You can see that the (vegetable) dyes are largely picked up by the skin rather than the scales, which are larger on older animals. Rays also feature this knot of bigger, thicker scales along the spine. The bigger the scales, the more difficult to cut the skin in a straight line: they’re hard and brittle, and put up a fight when subjected to my breakaway knife, whose blade had to be changed constantly. Conservation and identification was covered quite effectively by Margot Brunn here on the Conservation DistList. Since Brittany’s case was new, we didn’t have to consider adhesives and ethics as carefully as if it was original to the automaton.

On to the covering: