Musings

Tortoiseshell Box Conservation Series #1

For the past several months I have been working on many interesting projects from a client’s large collection of exquisite tortoisehell objects d’art (that’s French for “real pretty thing”).  Now that I am back in the studio after almost three months of inaction resulting from my broken hip, these projects are coming to fruition.  Over the next few weeks I will be chronicling the projects beginning with the simplest and working towards a nearly complete reconstruction of a complex tea caddy.   These blog posts will not be sequentially consecutive, in other words they will be interspersed with other postings but I hope to get a new update every day or so.

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The first artifact in this series was a tiny box, probably for snuff, with a the box intact but in dire need of a cleaning and polishing.  This artifact was a new acquisition for the collection, so the condition was “as received” following an auction, not the condition of the collection in situ.

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One of the fascinating technological features of this little box, which measures approximately 3-1/2″ x 1-1/2″ x 1″, is that the lid is formed from heavyweight hawksbill turtle shell while the box is formed and carved from what I believe is water buffalo horn.  If you look carefully you can see the grain of the buffalo horn you can see this grain.  If I could figure out how to get my Canon G16 to actually focus on what I want to shoot, it would be easier.  I may actually have to break down and read the instruction manual.  I never ha that problem with my beloved Canon G12, but a sudden deceleration event rendered the latter non-operational.

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The only real issue with this snuff box is that the surface was no longer presentable, so the object was no longer fulfilling one of its primary functions.  The strategy for obtaining the appropriate presentation surface revolved around two points, first to clean off the encrusted grime, and second to abrasion polish the underlying shell surface as necessary.  There would be no way to know how much of the second step was necessary until the first step was completed.

Cleaning tortoiseshell is a tricky business sometimes, as shell is a long chain crosslinked protein, namely keratin, which is the same protein macromolecule that constitutes your own fingernails, skin, and hair.  Thus, it is a material sensitive to water.  But some times aqueous cleaning is the most efficient approach for dusty grime.

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In this case my testing confirmed that spit cleaning was the best approach.  And yes, I mean spit.  My approach was to dampen swabs in my mouth — late in the morning or afternoon, so that any food debris from breakfast or lunch and any toothpaste residue is long gone —  and moisten the shell surface with the wet swab.  This has the advantage of applying the cleaning and digestive chemistry of the mouth to the cleaning problem, with the added advantage that mouth-moistened swabs do not flood the surface of the hygroscopic material enough to cause any problems.  (Chemistry is our friend!)  As soon as the cleaning and grime removal has been accomplished, I dry the surface, usually with cosmetics sponges, followed by a damp wipe with clean cosmetic sponges moistened with a few drops of distilled water.

The result was heartening in this case, revealing that any abrasion polishing afterwards would be minor.

And that’s what comes next in this series.