This summer we have been joined at the Alice by Adelaide Steinfeld, the first recipient of the Burke Scholarship established in honor of long-time museum board members Joseph and Joan Burke. Adie has been dividing her time between the Alice and Miner Institute, working on a variety of archival and collections-related projects. During a day spent cleaning part of the ceramics collections, she became interested in the history of ceramic repair techniques. This blog post is the result of her research!
Adie cleaning a very dusty tureen lid
Alice’s Ceramics Collection
Alice T. Miner’s antique collection began with ceramics. During her time collecting in the early 20th century Alice was able to acquire a large and varied collection of mostly English and French pottery dating from the late 18th to mid 20th centuries. Throughout her collection we can see evidence of the lives these pieces led. Several have cracks and chips, in some cases even whole pieces have broken off. There is also evidence of past conservation treatments to repair this wear and tear. We can see this in fragments that have been glued together, sections of loss that have been replaced, and what appear to be staples joining broken pieces together.
Repairing Ceramics
As ceramics are often utilitarian objects, it is almost inevitable that throughout their lifetime they will incur damages from consistent use. Ceramics are a brittle media that is mainly susceptible to temperature changes and breaking from being dropped or mishandled. Likely for as long as people have been using ceramics, they have been repairing them. The methods that evolved for doing so were carried out both by specialized repairers, known as China-menders, as well as at the home by servants or housemaids. Repair techniques would vary depending upon the function and aesthetic value of the object.
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| Mug. Tan slipware with brown spots, ca. 1810. |
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| Detail of chip in mug, was likely never repaired as the object would have still been fully functional. |
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| Pair of Vases. White with painted floral reserves, foliate and floral motifs in relief and decorated in blue, green, and gilt, ca. 1850. |
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| Detail of vase. This was primarily a decorative object that has been repaired with an unknown fill. The fill appears to be dark grey and there is a large piece missing at the corner. |
Joining Broken Pieces
The most common type of repair needed for ceramics is the joining of broken pieces after a break has occurred. Methods for joining pieces of pottery have been around since we started making pottery and involve the use of either an adhesive or mechanical technique.
Prior to the early 20th century synthetic adhesives were not stable or widely accessible. As a result people mainly relied on natural adhesives such as starch pastes, natural gums, resins, protein binders, beeswax, and fats (animal glue). Because these materials would often be combined together and due to their poor aging, it is difficult to analyze the organic materials that have been used in past treatments. A few inorganic materials may have been used as adhesives as well, including Portland cement, waterglass, and sulfur.
Due to the instability of these adhesives, mechanical methods to repair ceramics have been in use since antiquity. There are three main techniques used: tying, lacing, and riveting. Tying, much like the name implies, uses a binding (metal, reed, or twine) to tie around the two broken pieces and secure them. Lacing and riveting are very similar techniques. For lacing holes would be drilled through the ceramic and then a wire would be threaded through, joining the two pieces. Riveting, likewise drills holes into the ceramic, though not all the way through. A piece of metal would then be used to join the two halves together--giving the appearance of staples. Riveting was common in China by the 17th century and had spread to Europe by the 19th century.
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| Tureen. Chinese export porcelain, white orange peel glaze with blue and gilt borders and scenic reserves in sepia, early 19th century. |
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| Detail of tureen showing rivets and metals visible on the exterior. |
Fills
Often when a ceramic breaks it will have some loss, either in the form of chips or a larger missing piece, that require the addition of a fill material in order to be fully repaired. If these losses were large enough they would often be filled with other ceramic fragments. Other times we see that a whole part has been replaced with a newly fired and glazed addition. In both of these cases we need an additional material to adhere either the new pottery fragment or the replacement to the original vessel. Often this comes in the form of one of the adhesives mentioned above. For example animal glue would have been used in excess along with a pigment to produce a fill that was quite strong. Wax that was pigmented and mixed with resin forms a durable fill, but ages very poorly. Clay could be used as a fill, with either shellac or animal glue acting as an additive. A low firing glaze could also serve this purpose, though this has to be done very carefully in order to avoid damaging the original ceramic. Cement can also be seen but it causes the migration of salts to the ceramic, therefore degrading the original object.
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| Tureen. Blue transfer print, Beauties of America: Boston Alms house (body)and Cambridge College (lid). John Ridgway, English, ca. 1825. |
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| Detail of tureen lid showing rivets and metal bars joining the broken pieces |
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| Detail of tureen handle that appears to be a replacement, with a matte finish and metal pegs that have been used to attach it. |
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| Teapot. Blue transfer print, floral pattern, ca. 1825. |
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| Teapot lid showing dark blue green fill material used to repair a loss. |
Finishes
Depending on the ultimate purpose of the repair—aesthetic or functional—the ceramic repair might be left unfinished or painted over to match the original finish. Most common paints and coatings were shellac with pigment as they would harden and produce a glaze-like finish.
Contemporary Repairs
In the 1930s there was somewhat of a revolution in the types of adhesives available as the development of modern chemistry allowed for the discovery of plastic, synthetic resin, and rubber glues. Common glues in ceramics conservation include acrylic copolymers, though in some cases epoxies are more suited to the repairs. These glues are more stable and longer lasting, and as a result ceramic repairs were able to become a lot more seamless in their appearance, often being hardly detectable. There are numerous objects throughout the collection that appear to have been repaired in this manner.
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| Bowl. Mocha ware, brown stripes enclosing caterpillar band in mottled blue and brown, early 19th c. |
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| Detail of repair on bowl. Discoloration along the seam, with some staining on the surface of the ceramic. Adhesive is unknown. |
Addressing Old Repairs
The modern conservator is usually looking to make a repair that is minimally invasive, reversible, stable, and doesn’t impact the overall appearance of the object. This is often at odds with these older repair techniques which didn’t have the same aesthetic and long term goals in mind. In many cases, especially with the use of organic adhesives, they aged very poorly causing discoloration on the original object. Other fills may have caused salts to deposit on the surface of the ceramic, which can lead to fracturing and cracking down the line.
Generally, when it is possible to safely and effectively undo one of these older techniques, conservators will do so to avoid having the object degrade further. There is some debate about undoing riveting and other mechanical techniques, as they are viewed as somewhat of an art and point to the objects’ history.
