October 2008 Jamestown Project By: Kenya Brown Fusciello,
Conservator
The Jamestown Project derives from Historic Jamestown, Virginia, where an archaeological assessment recovered artifacts including many iron and ceramic fragments, a significant number of them being Colonial period pipe fragments. These excavations, led by noted archaeologists J.C. Harrington and John Cotter, occurred between the 1930s and the 1950s. Subsequently, they were treated by Civilian Conservation Corps (CCC) and National Park Service staff.
Artifacts uncovered at Jamestown are from the Colonial period of the early 17th century. When English colonists settled on the island at the time it was heavily wooded and contained marshlands. Jamestown was settled in 1607 and served as the capitol of Virginia for 92 years. By the arrival of the 18th century, Jamestown’s infrastructures were soon abandoned by its inhabitants. Tobacco fields were then cultivated in place of abandoned farmsteads (Jamestown Archaeological Assessment, 2001:3). Today’s Jamestown is a historic site jointly administered by APVA Preservation Virginia and the National Park Service location where thousands of objects dating from these periods are in storage facilities and on display at the park’s visitor center for public exhibition.
In 2003, Jamestown staff members prepared the site for the onslaught of Hurricane Isabel in accordance with its emergency plan to prevent any type of flooding. Unfortunately, the combination of the hurricane and its related storm surge brought in waters from the nearby Pitch and Tar Swamp measuring five feet deep at the National Park Service Visitor Center. Consequently the artifacts were adversely affected and are undergoing treatment at the Maryland Archaeological Conservation (MAC) Laboratory in St. Leonard, Maryland. Approximately 34,000 of those objects were sent for re-treatment as a part of an agreement between the National Park Service under the Department of Interior and the MAC lab. The remaining objects were being treated in other major laboratories on the east coast and at a National Park Service facility near the park.
The MAC Lab found, by Fourier transform infrared spectroscopy (FTIR) testing, that the iron objects were coated with paraffin wax intended to act as a protective layer and/or consolidant in some cases as a result of their first treatment in the 1950s. Although the wax offered some protection, the irons suffered some corrosion due to brackish water flooding stemming from the hurricane.
   Iron artifacts that are exposed to water and oxygen will show a
reddish brown corrosion superficially (Fig.1). At lower relative
humidity (RH) levels, corrosion is probable if the surface has been
in contact with salt also known as chlorides (Canadian Conservation
Institute, 2002). As with most of the irons in the project, rust
will appear on the surface layers of the objects if the indoor RH
is at 65 percent or higher. Exposure to chlorides can contribute
to the corrosion which is evident from the loose powdery residue
seen on many of the irons from Jamestown.
(Fig.1, Irons before dewaxing)
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(Fig.2, Measuring chloride levels)
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The first stage of the re-treatment and stabilization process begins
by placing the objects in a solvent recycling still using a hot
xylene vapor for six hours to remove old paraffin wax layers remaining from
the previous treatment. Once they have been de-waxed they are moved
into various storage bins containing reversed osmosis water (RO)
and a small percentage of sodium hydroxide (NaOH) with regard to
volume of RO used. Chloride readings are logged daily by the laboratory’s
conservators in order to determine if the levels indicate the removal
of soluble salts from the objects (Fig. 2).
The objects are removed from desalination and are immersed in bins
containing deionized water. The bins are placed in a hot wash at
a temperature of 140 degrees Fahrenheit, 65 degrees Celsius for
the elimination of any more soluble salts and to neutralize the
objects. The water’s pH is measured and changed daily until the
level reaches the neutral standard
measurement.
Next, the objects are set to dry in an oven for no more than three days,
thereafter tannic acid is applied. (Fig. 3) Tannic acid is comprised
of a group of water and alcohol soluble products that are effective
for the stabilization of iron oxide and converts it into an iron
tannate after application (Matlby, 1998). Jamestown artifacts may
receive between two to three coats of tannic acid depending on the
extent of the object’s corrosion. Thereafter, the irons lose their
brownish color and take on a black finish (Canadian Conservation
Institute, 2002).
The final phase in treatment includes a protective coating containing
Acryloids B48 and B67 mixed in a solution of acetone and xylene.
After the objects are coated they are labeled and packaged for return
to the Jamestown facility (Fig. 4).
 
(Fig. 3, Tannic acid application) (Fig. 4, After tannic acid and coating)
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(Fig.
5, Cleaning pipe fragments using acetone)
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Unlike the iron, the treatment cycle for the Colonial pipe fragments does
not require as many steps. The pipe fragments are separated in small
nets according to their conservation accession numbers and set in
an acetone solution for a period of one to two days. The pipes were
removed from the solution and then cleaned using a cotton compress
containing acetone (Fig. 5).
Once the cleaning process is finished they are placed again in the nets
to soak in deionized water where daily chloride levels were recorded.
PH levels between four and five are required in order to receive an accurate chloride reading measured in parts per million (ppm). If the ppm results were below the number five, the fragments were removed from their nets and put onto a tray to
dry for one to two days. Each fragment is labeled, coated with a
mineral oil mixture to protect the number written, and packaged
for return to Jamestown.
Approximately 23,000 ceramic pipe fragments and a number of wood
objects have completed treatment and have been returned to Jamestown’s
facilities intermittently throughout the span of the project. There
remain over 5,000 objects that are still undergoing assessment and
treatment including iron and ceramic shards. The project is anticipated
to end September 2009.
References
Matlby,
Susan
1998 Old House Journal. Rust Converter. Electronic Document. http://www.alan.net/prgshoptips/rustconv.html accessed September 15,
2008.
Canadian
Conservation Institute
2002 How to Care for Irons. Electronic Document. http://www.cci-icc.gc.ca/publications/cidb/view-document_e.aspx?Document_ID=437
- accessed September 15,2008.
Jamestown
Archaeological Assessment
2002 National Park Service, U.S. Department
of Interior. U.S. Library of Congress, Washington DC.
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