Sunday, 9 February 2014

Prescott House Metal Objects - February 9, 2014

February 9, 2014

Prescott Hose - Archaeological dig, Fall 2013
In a previous post I showed how I re-assembed a glass bottle that was found in pieces at an archaeological dig at Prescott House, near Wolfville, Nova Scotia.  The first photograph here shows us working on the dig.  We were in a class at Acadia University learning about archaeology and history in the area.  The three of us on the left are working in an area that appeared to be part of the wall or foundation of a building.  The original house from the early 1800's can be seen in the background at top right.  Behind us is a road to a grounds keeper's shed.

I was given the opportunity to work on four metal objects that were found at the same location.  These are a belt buckle, ice creeper (not discussed here), button, and bone handled knife.  Each of these came to me in a plastic bag labelled with the location in which it was found and still immersed in the original soil in which it was found.  This is the best way of removing these from their original location because it allows me to assess the impact of separating them from their environment and perhaps, if budgeting permitted, to get the soil analyzed.  For precious objects this would be a necessary exercise to determine the best route of treatment.  The constituents of the soil would help make the decision on which chemicals to use for cleaning, preventive measures, and storage.  Since, in this case, we are dealing with a limited budget and non-precious objects (objects of lower value) this was not done.  However, it does not stop us from doing some basic conservation work on these interesting objects.

I have provided photographs of three of these showing before images in which you can see the results of cleaning.  There are several important lessons to be learned from this work.  All these had a very serious amount of corrosion products in an active state.  This was the result of many years where they were immersed in soil and sand subject to rain and snow with alternating freezing and thawing conditions typical of Nova Scotia.  All of which exert considerable stresses.

Bone-handled Knife
The bone handled knife was the best example of the stresses of moisture.  It was moist when it was removed from the soil and rapidly dried out.  One part of the bone handle came loose within minutes.  I suspect the moisture was holding it together.  This is repairable with the same adhesive used to reassemble the bottle in my previous post, Acryloid B72 restoration adhesive.  The blade of the knife was obviously broken at the end with a jagged edge.  There is an obvious pattern to the material showing as a layer over much of the blade.  I suspect that this was the sheath in which the blade was kept.  Very little cleaning was done on the blade to preserve this material for possible future testing.  All loose material was carefully brushed off  and the wax applied overall as a preventive measure.  The wax had the added benefit of sealing up many small fractures in the bone and making them much less visible

Buckle - front - before cleaning
Buckle - Front - Finished
The buckle shown here was a mass of corrosion, sand, soil, and plant root.  The layers of corrosion were heavy enough that it could not be completely cleaned off.  No parts of it was movable and the underlying metal is not visible at all.  Once again, any loose material was carefully removed and a layer of wax was applied.  This object reacts strongly to a magnet so is likely made of iron.

Button - Back - Finished
Button - Back - Cleaned
The button shown here proved to be one of the more interesting objects to work on because after cleaning and treatment a very clear pattern became visible on the back.  It is characteristic of fibres in cloth suggesting that this is either the remnants of the material the button was sewn onto or a piece of cloth it was laying next to while in the ground.  I did very little cleaning of this side - using only a very fine, soft brush to ensure that none of this material would be removed.  It is possible that in the future someone may wish to have the material removed and examined so preserving it was my priority.  The front had a pattern of two small circles and bumps but was very obscured due to corrosion.  The condition was such that we cannot identify a date or its usage.  Once again, a fine layer of museum grade wax was applied to seal it from further moisture damage.

In all cases these metal objects were accompanied with a two page laboratory record document that provides a detailed description, measurements, structure, possible history, manufacture, treatment applied, before and after photographs, storage and exhibit environmental control suggestions, and any other additional notes that were relevant.  These documents becomes part of the permanent record for the province of Nova Scotia and Prescott House the owners of these important objects.