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This year's field season, during the week of October 3 - 8, 2004, was the first investigative excavation since 2000, on the shipwreck site. The project had multiple goals but the primary focus was to evaluate the accuracy of the gradiometer surveys conducted in 1999 and 2001 through test excavations. However as there was also a possibility that some artifacts would be recovered, conservators from the QAR Conservation Lab were also part of the field team. To prevent deterioration of artifacts on recovery the conservation process needs to begin as soon as the object is brought to the surface. The QAR Conservation Lab had a conservator onboard at all times during the fall field season. Conservators are responsible for the care of the artifacts from the time of recovery to the time they reach the museum curator's hands.
The decisions to recover an artifact were made based on
whether or not they were at risk of damage if left on the site, easily
conserved and/or diagnostic. The 2004 field season has prepared the conservation team for the fieldwork to be done in 2005. As we continue to move objects to the museum, we are making room for more to come. Artifact Transfer to NCMM
Cannon Dehydration The last two months have been particularly exciting as Cannons 19 and 21 have finally been removed from their treatment tanks, dried and given protective surface coatings - they are the first cannon from the shipwreck to reach this stage. Cannon 19 & Cannon 21 have been undergoing electrolytic
reduction treatment for almost four years to remove soluble salts (particularly
chlorides). If the cannon were allowed to dry out while still retaining
high levels of salt in them they would be at great risk of corroding
in the future. The concentration of chlorides in the electrolyte (treatment
solution of 2.5% sodium carbonate in water) has been regularly checked
to monitor progress; the concentration in the solution being taken to
be an indicator of the concentration of salts in the object itself.
Finally, in September it was determined that the levels of chlorides
in the solutions were so low (25ppm) that the process had effectively
reached an end. The next step was to remove the cannon from the electrolyte
and thoroughly rinse the sodium carbonate (alkaline) from the cannon.
Both C19 and C21 were immersed in successive baths of clean (by reverse
osmosis) water
for about a week each until the water remained neutral indicating that
sodium carbonate had been rinsed away. The surfaces of the cannon were patted dry and the first protective coat of 10% tannic acid in RO water was applied with soft toothbrushes to get into all the crevices of the surface. Two more coats were added in the same manner before the end of the day and the cannon were left to dry. Since then the cannon have had three more applications of tannic acid solution. We are closely monitoring the cannon, constantly on the look out for any signs of corrosion - which would be indicated by spots of orange rust appearing on the surface - So far both have shown no major sign of trouble. The cannon have been moved from our large warehouse Lab (which is unheated) into our Lab in the main building at ECU's West Research Campus (VOA). This is a good time of year to move the cannon into this treatment stage because the humidity is now so low - especially in our heated lab where the relative humidity is about 20% most of time. At higher humidity levels the cannon would be at risk of actively corroding. The cannon will receive a few more applications of tannic acid solution before being given protective coatings of lacquer and wax. We will then continue to monitor their stability for a few weeks before their transfer to the Museum in Beaufort. We'll keep you posted on the progress of C19 & C21. ECU Public Relations
Clint Bailey, Director of Marketing for East Carolina
University contacted us about their interest in making a short film
about the QAR Project, to air on the local ECU cable channel
99.
Gunlock QAR 326.000 Update In September we reported on how X-raying
the concretion around the gunlock QAR326.000 showed us numerous
lead shot within the concretion. From the shipwreck so far we have approximately
12,000 lead shot and but only one gunlock.
Next month, conservators make a start on the concretion `Baby Bertha' (509.000) which may contain another cannon…. |
Queen
Anne's Revenge
The
first objects to come to the surface were small ballast stones and small
pieces of iron concretion recovered from sand covering the site during
the dredging process. The dredge is the equivalent of the terrestrial
archaeologist's shovel; it pumps the sand to the surface where it is
filtered through a screen on the deck of the dive boat, before being
returned to the sea. Artifacts recovered in the screen were given a
find number and documented as dredge spoil. Once a few layers of sand
were removed from the site, artifacts began to appear and were thoroughly
documented by archaeologists through drawings, photographs and video.
Two lead artifacts, a lead sounding weight with marks and a folded lead
sheet with nail holes were recovered due to their vulnerability and
the minimal conservation required. A few concretions were recovered;
one appears to be a cannon shot and three others resemble bar shot with
various objects concreted to it as well. Once the objects were recovered
they were given numbers, provenience information was obtained, and placed
into containers with seawater. At the end of each day, all the objects
recovered for that day were removed from the boat to a secure store.
At the end of the week, all the objects recovered were padded and packed
safely for their journey to the conservation lab in Greenville. The
objects were first put into 50/50 seawater to tap water for about two
week to gradually introduce the objects to a less saline environment.
The lead was placed into tap water and the concretions are stored in
a 0.5% sodium carbonate solution in tap water to prevent corrosion of
some exposed iron.
Curator
Connie Mason arrived on October 21st, to transfer almost 900 artifacts
to the QAR Repository at the North Carolina Maritime Museum in
Beaufort. Artifacts transferred included approximately 700 nails, a
copper alloy sail needle and small pins, numerous lead artifacts, and
cannon shot. Once the objects are conserved, they are placed in a controlled
environment and monitored to make sure they are stable.
Before artifacts reach the museum they undergo study and thorough documentation.
Graduate Assistants, Kim Smith and Kristin Koshgarian helped with taking
the final weights, measurements, and sketches as well as marked the
objects with their QAR numbers. All the artifacts were photographed
and the database records were completed with recommendations on storage
and display for the curator. These artifacts can be seen on display
in Beaufort.
The cannon were then removed and the surface was brushed with soft toothbrushes
and running RO water to remove the loose corrosion products.
The purpose of the film would be to educate students, staff, local community
and surrounding areas about activities at the QAR Conservation lab at
ECU and about some of the processes the artifacts go through on their
journey to the museum. Gary Weathersbee, also of ECU Marketing and the
Producer/Director of the short film hired Al'eon Media Inc. out of Cary,
NC. Owner/Videographer Scott Schenck and Grip, Andy Poe joined us at
the lab on November 18th to film the portion in the conservation laboratory.
The film crew had a busy week traveling about eastern North Carolina
filming different parts of the story, including Fort Macon near the
shipwreck site and at the museum in Beaufort - the final destination
of all the QAR artifacts.
To
reveal the gunlock it would be necessary to remove the lead shot ridden
concretion around it with an air scribe. Once the concretion and lead
shot were cleared away, the main spring, tumbler and part of the sear
spring were revealed. The condition of the metal in the main spring
and the sear spring was heavily corroded but the tumbler remained solid
metal for the most part. When the lock was originally fashioned, all
of these pieces would have been removable and separate. With the gunlock
parts still attached the artifact was photographed and drawn. The gunlock
was placed back into electrolysis to harden the iron and remove more
chlorides before the remaining concretion is removed. Progress of this
artifact will be posted in the future.
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