NHHC Conservator
Today’s blog is part two of our spotlight on the recently conserved Commodore Samuel Barron Sword (yataghan), now back in HRNM’s collection. We are excited to have our colleague, NHHC Conservator Karl Knauer, share with us the conservation process, as well as his work on this artifact. To read part 1 of this blog, click here.
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As conservators in the NHHC Conservation Branch (“COBRA”), we work on artifacts in the NHHC’s varied collections, including those of the Navy’s museums.[i] After receiving an initial inquiry from HRNM about potential conservation treatment of this Ottoman sword we were intrigued. In any conservation process we assess many aspects of the artifact, including materials and the historical context of its creation and use, to determine the best course for treatment. At first sight it was clear that this yataghan was of exquisite craftsmanship and would be a challenging yet rewarding conservation experience.
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| Barron yataghan and scabbard before conservation, disassembled for evaluation and treatment (Conservation Branch NHHC) |
The assessment started with a thorough visual examination before other methods of analysis. Here we carefully handled the sword and scabbard to look closely from all angles. I noted a few loose and missing components, unraveling grip-wrapping, and fingerprints etched into its blade. The dark overall tarnish suggested “benign neglect,” which was potentially good news. Excessive polishing over the years could have dulled and worn away the exceptional detail of both sword and scabbard. I also examined the wooden liners of the scabbard. These components, typically hidden from view, are integral to the assembly of the ornate silver sections.[ii] A conservator’s main objective is to stabilize artifacts, not just treating its surfaces, but also making sure that the artifact won’t fall apart, and that any overall deterioration is slowed. This could involve simply providing recommendations on the best environment and preventive measures to prolong its preservation but typically involves at least some sort of cleaning to remove potentially damaging surface grime or other contaminants. For this sword and scabbard, the condition justified more interventive treatments for stabilization.
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| Here we can see a portion of the scabbard before cleaning (left) and after cleaning (right) (Conservation Branch, NHHC) |
For structural stabilization of the scabbard and “compensation for loss” in missing areas, we aim to make these repairs reversible and “not falsely modify the known aesthetic.”[iii] However, cleaning the tarnish off the scabbard and reducing the etched fingerprints on the blade are irreversible courses of action and should be undertaken with deliberate caution. Polishing the silver was straightforward and gentle, albeit time consuming.[iv] On the steel blade, the dark, disfiguring corrosion products and etched fingerprints were more challenging and resistant to gentle cleaning methods. Such marring cannot be fully reversed and, in some respects, comprises a part of the sword’s history and age. At a minimum, we try to degrease the blade of any residual oils from past handling and make sure that such corrosive etching doesn’t further rust the surface. With careful testing I devised a form of localized electrolytic reduction that allowed for removal of the darkest corrosion products without immersing the whole blade.
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| Using low voltage current applied to the artifact through a mild electrolyte, rusted areas slowly yielded to selective cleaning. This process is seen here. (Conservation Branch, NHHC) |
Once cleaned, I applied a stable wax paste to the steel surfaces, which slows the formation of any new rust and protects the surface from any potential contamination. Similarly, I coated the silver surfaces with a protective acrylic lacquer to help slow the rate of tarnishing in the future. I carefully stitched the fragile textile on the grip with very fine, reversible threads and filled its losses with pieces of hemp-fiber cloth. I also stabilized the wooden scabbard inserts using archival adhesive and fitted pieces of painted archival paperboard. Addressing the most notable losses on the silver scabbard was the final step. The areas around these losses were fragile and vulnerably prone to snagging and bending, so we needed to add some form of stabilization. Because these areas are so ornate, it was important to “aesthetically integrate” (or appropriately blend-in) whatever I would use to fill these voids. Fortunately, the ornate patterning on the scabbard often repeated, providing ample sources for motifs that could be copied with silicone molds. I took impressions of the required areas to subsequently cast them out with appropriate materials—but the trick in this instance was using a suitable substance that was not visually disruptive. Tests with a variety of conventional restoration materials yielded unsatisfactory results. However, recently another conservator used a nearly 200-year-old technique known as electrotyping to fabricate missing metal components in copper with excellent results.[v] Electrotyping is a technique whereby metal is deposited into a mold from an electroplating solution (something like a 19th century version of 3D printing). Experiments using this method were much more successful.
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| Original “filigree” collar located below the scabbard opening (left) and an electrotyped silver facsimile (right) used in creating fills to aesthetically compensate for lost areas. (Conservation Branch, NHHC) |
Scaling up this technique, I was able to make repairs to the intricately detailed “filigree” areas at the opening of the scabbard, as well as the lost scabbard tip. This last section proved somewhat tricky because of the taper towards the scabbard’s end. Fortunately, I was able to use the same method as the other silver work and made a mold using the repeated patterns from the rest of the scabbard. Although the repeating pattern was easy enough to replicate, the very end was left somewhat vague, as the shape of yataghan scabbard tips can vary and I wanted to avoid falsifying the appearance. The electrotype tip was then fitted with a plastic sleeve that would allow it to be secure but easily removable from the end of the scabbard.
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| Here you can see the conserved sword and where new material was added to present a visually complete artifact. Replacement elements are documented and labeled so they are distinguishable from the existing historic materials. (Conservation Branch, NHHC) |
As a final step, we constructed an archival housing (fitted box) to safely transport the piece back to HRNM, as well as serve as an interim storage container. It was a privilege to be able to work on such a cool piece of history and remarkable craftsmanship! Hopefully this amazing sword will serve as a touchstone to the history of the Barbary Wars for many museum visitors to come.
Notes:
[i] For more information about NHHC’s Conservation Branch visit: https://www.history.navy.mil/our-collections/conservation-branch.html and https://www.dvidshub.net/news/385745/cafeteria-conservation-lab-nhhcs-conservation-branch-five-years
[ii] Sampling miniscule slivers of this wood and looking at them under a microscope revealed characteristics typical of the hardwood known as hornbeam (Carpinus betulus or the related Carpinus orientalis). Examination of the textile wrapping on the grip under the microscope also revealed that they are plant fibers.
[iii] Conservators follow a code of ethics and guidelines that help us choose the best and most appropriate methods in undertaking conservation treatments. This code can be read here: https://www.culturalheritage.org/about-conservation/code-of-ethics
[iv] I made slurries of calcium carbonate (chalk) in water or solvents and gently applied these to the surface and buffed them with soft cloths and more locally with miniature cotton swabs (like mini Q-tips that we make ourselves), the residues of which were finally cleared by rinsing.
[v] Erdmann, Mark (2017). "Copper Electroforming: An Alternative to Casting for Metal Replication." AIC Objects Specialty Group Postprints, Vol. 24, 2017. pp. 445-453 http://resources.culturalheritage.org/osg-postprints/wp-content/uploads/sites/8/2021/11/osg024-2017.pdf
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