Sunday, 30 December 2012

Roundhouse Objects Conservation - Dec. 27 2012

December 27, 2012

Historical Object Photography

My conservation work on the Kentville Railway Roundhouse objects is nearing completion of the cleaning phase with only a few objects left to work on.  I have started taking photographs to upload to the Kings County Museum collections database called  The museum is now closed for the winter (opening again in mid-March 2013) so this gives me an opportunity to add all the roundhouse objects information onto the database and include higher resolution photographs which I took on Thursday December 20.  Conservators refer to historical object photography as record photography.  Our goal is to produce photographs that allow viewers to see the objects as much as possible in their natural state that shows their true colours, shape, identifying marks, and condition and for researchers to zoom in for as much details as possible for such things as maker's marks.  Since we do not have a true photographic studio we have used what equipment we have on hand as donated to the museum or what photographers are willing to lend us.  The photograph below is the set up I used for this purpose.  The essential and basic pieces of equipment as shown are: a DSLR camera, a tripod, a light box, spotlights, and a scale (not shown here).  The light box in this case provides a white background on all sides as well as top and bottom.  The light box is a portable one that is easily assembled from a folded up state.  

Record photography light box set up
I found that 4 spotlights worked best: two at the top and one on each of the left and right sides.  All are angled towards the middle where the object will be placed.   The spotlights are not ideal but work reasonably well for our purposes.  It would be best to use a type of light that is diffused.  That is, not so focused, but we had none available at this time.  The spot lights are set up to not touch the sides of the light box because they get quite hot.  You can see in this photograph how the object is placed in the middle with white sides all around and soft light throughout.  It is best to remove all other sources of light such as overhead lights and from windows which can reflect off the objects.

Here are some of the guidelines I use when taking record photographs of historical objects:
  1. use a DSLR (Digital Single Lens Reflex) camera where possible although some point and shoot cameras do work well.  I have used a Canon PowerShot with good results,
  2. most objects can be photographed at about a 45 degree angle,
  3. use the largest sized JPEG setting or RAW setting but remember that RAW takes up considerable space,
  4. use custom white balance (photograph the white space anywhere in the light box and use it to set the white balance),
  5. position the lights to highlight the object with as little reflection as possible,
  6. use macro setting for close up of identifying marks if there are any,
  7. use a scale nearby but not touching the object,
  8. angle the object if it highlights any markings otherwise they should be straight vertically or horizontally,
  9. take at least four photographs: one from the top the other from the bottom both with and without the label.
Below is an example of the photographs I took of a power line insulator.  Each one has the label shown beside it where the accession number can be used to do a search on to get additional information.  I usually take the same pictures without the label to put on the database.  Having the label here simply makes it easier for anyone to do follow up on research if they are starting from this BLOG.  In this case the accession number on the label is 2007.012.021
Power line insulator - top
Power line insulator - bottom
Do-it-yourself Tip: In the past I have made a small light box when a commercial one is not available.  You can use a large box placed on one of its long sides.  Cut openings on the two narrow sides and top (the other long side) and cover the openings with white tissue paper.   I have then used ordinary lamps (desk lights) shining through the tissue paper as lighting.  Place a sheet of white paper large enough to cover the back and curve onto the bottom.  Place the object in the middle of this to take your photographs.

Wednesday, 19 December 2012

Roundhouse Objects Conservation - Dec. 18 2012

December 19, 2012

Metal Objects Conservation....continued

In a previous post I showed how I clean up corrosion products (rust) and other material from metal objects that were found in soil under moist conditions.  I mentioned that I consider this as a two step process in that once cleaned (Step One) these objects should be stabilised (Step Two) to prevent further deterioration due to the possibility of high relative humidity.  Of course, the cleaning process has the side effect of exposing more of the metal surface to moisture and oxygen thereby promoting the accumulation of corrosion products (rust).  I use conservation grade wax to coat the objects to provide a barrier to contact with moisture and oxygen combination thus ensuring that they will last a considerable time into the future.  Not all objects would be treated this way but certainly most smaller objects can be.  Particularly those with high iron content since they are susceptible to rusting.  It is not practical to do this with larger objects as you will see by the techniques I use.  I prefer to use Renaissance Micro-crystalline Wax since it is pure and safe to use on most objects plus the added benefit of being developed by the British Museum for use on a wide range of historical objects such as furniture, leather, ivory, onyx, marble, metals, and so on.  For non-metals, it is typically applied as a thin layer and then buffed with a soft cloth.  For metals, it is often used over top of an anti-corrosion undercoating.  For our purposes in a small, community museum setting it is not always affordable to purchase anti-corrosion undercoating so simply applying a layer of this wax will serve to protect the object at minimal cost.  I use heat sparingly applied to the wax and object to help smooth it into a thin, uniform layer.

Back of padlock with tools and materials used to apply wax.
Before heating, I apply a thin layer of wax to the object with a small, coarse bristled brush. I then apply minimum heat via a hair dryer or heat gun to melt the wax and brush it again to remove lumps and ensure low spots and all the surface is covered in a thin layer.  The heat source must be carefully applied to ensure that it is not too hot to handle.  In the photograph to the right you can see the tools and materials I used to treat the padlock.  I placed the object on a wooden cutting board as a neutral material which would not readily conduct the heat.  I used a paper towel (above the brush) to clean excess wax off the brush.  I find that in a short time the object becomes quite warm to the touch.  Keep in mind that most metals expand when heated and contract when cooled so it is best if the objects to be treated are comprised mostly of iron rather than an alloy since different metals expand and contract at different rates.  Alloys for the most part would be handled differently.

In the photographs below I show the railway padlock I worked on with the wax applied before it was melted and then after it was melted so you can see the difference.  The brush is the right tool to use since it aids in getting right into all the depressions and allows for us to smooth out the excess wax around all the bumps, cracks, edges and depressions.

Padlock with wax heated and smoothed
Padlock with wax applied before heat

The edges, rivets, depressions, lettering, and contrasting colours are all still visible after the wax is applied and smoothed by applying heat.  The object on the right is now protected from moisture, oxygen, oils from handling, pollution and so on.  It can be safely packaged, stored away, and maintained in this condition for many, many years.

Conservation Tips: Treating simple metal objects can be done with minimal time and cost as shown above.  Reversing the process is relatively simple by carefully reheating the object and wiping off the wax with a soft cloth.  I suggest wearing gloves such as oven mitts that will protect your hands from the heat applied and using a thin board as a working base.  As with most objects it is always a good idea to consult with a trained conservator beforehand who can assess the object, determine the best treatment, and provide an estimate of the cost.  The above treatment has been done successfully on railway spikes, a railway valve wheel, a padlock and these archaeological objects: hand made nails, a key, a short length of chain, a shoe buckle.

Thursday, 13 December 2012

Roundhouse Objects Conservation - Dec. 11 2012

December 13 2013

Metal Object Cleaning....Continued

One of the larger metal objects found at the railway roundhouse site in Kentville Nova Scotia is a wheel that was likely used to open and close a valve.  Perhaps, even, as part of a piece of steam equipment.  It came to the museum labelled as a brake wheel but the diameter is 22.5 centimetres which makes it quite a bit smaller than most brake wheels I have seen in photographs.  There are other clues to its possible usage that I will point out later.  It was heavily crusted with corrosion products (rust) so my effort was, as with other metal objects, to remove any loose material in preparation for applying a layer of wax to seal off the surface from moisture.  All material removed was saved in a sealed glass container.  Also, as before, the hope was to make clear any makers or other marks on the object.  There are some raised, embossed material possibly letters near the centre.  Of particular interest is what appears to be some small pieces of textiles (cloth) on the outside of the wheel and around the nut on one side of the short, threaded shaft running through the middle.  The opposite end of this shaft appears to be broken with a crack visible.  Was a cloth used to turn the wheel and torn or was the object thrown away along with some cloth?  We will likely never know.  Below are photographs of both sides of this object:

Wheel before cleaning with cracked bolt in centre
Wheel before cleaning with rusted nut in centre

Wheel material cleaned off and tools used.
The surface of the wheel had a sheen of grey and red corrosion some of which was very soft and easily came off with a toothbrush with hard bristles.  Quite a lot of larger crusted material was easily pried off with a scalpel.  There were a couple of bead shaped bumps to the right of the nut in the centre which were not removed.  They are reminiscent of material sprayed about during arc welding which I have observed in the past while helping my father with some of his welding projects.  The photograph to the right shows the tools and the material removed.  The textile (cloth) pieces can clearly be seen.

Wheel centre close-up showing faint lettering.
One of the benefits to this type of cleaning is the ability to bring out any marks found on the object.  In this case I was able to show the word Crane which is a maker of all sorts of equipment and tools plus the word Open with what looks like a line with a very faint arrow at the end.  The photograph to the right shows these faint marks.  Certainly, these marks imply it is a valve wheel rather than a brake wheel since some brake wheels usually have the words ON and OFF in different points along the wheel.

Friday, 7 December 2012

Roundhouse Objects Conservation - Dec. 4, 2012

December 7, 2012

Glass, and Ceramics Cleaning......continued

Butter dishes with maker's marks
I continued the cleaning process on mixed objects of different materials this week.  The ceramics consisted of 5 butter dishes which just needed wiping with a soft cloth and Orvus soap mixed with distilled water followed by rinsing with distilled water and a different soft cloth.  The photograph to the right shows all five dishes displaying the makers marks. These objects are in relatively good shape but with some red, rust like staining patches and a few scratches.  The rust patches are clearly visible on the dish in the lower left of the photograph.  The flip side of these dishes have no markings.  Although they appear to be very simple and of little importance, they, in fact, give us a glimpse into the purchasing practices of the railway at the time and into the manufacturer.   All show that they were made in England and two show that they were supplied by Nerlich & Co. This is an import company founded in 1858 in Toronto by a German immigrant to Canada.  My research shows that they imported goods from Germany originally but expanded to include goods from England after 1908 and wholesaling throughout the maritimes and most of Canada after 1891.  We can see several different makers marks with four showing the company name "Grindley England",  "W.H.Grindley & Co" and "Grindley Hotel Ware" while one other simply says "Made in England".  These different marks represent different batches very likely purchased at different times. W.H. Grindley & Co (Ltd) was established in 1880 at Tunstall in Stoke-on-Trent England and remained in business until 1991 when they went into receivership and were bought out by Woodlands Pottery.

Bottle main body with crack
Bottle top with material deposit

Bottle interior material removed
I cleaned a large brown bottle which had some material deposited inside.  The first photograph above shows the main body of the bottle with a large crack in the middle before it was cleaned.  The second photograph above shows the top of the bottle before it was cleaned with material deposited along the neck and top of the main body.  The photograph to the right shows the material removed.  Again, I carefully removed whatever would come loose inside by using a shish-kabob stick and Q-tips attached to the end of it.  I then rinsed the inside and out with Orvus soap and distilled water followed by rinsing with distilled water.  I used several Q-tips to wipe off any leftover material from the inside.  The outside was wiped with the soap mixture and a soft cloth and then rinsed with distilled water and a different cloth.  I decided to keep the material removed in a separate, sealed container because it appears to have some material that may give a clue to what it originally contained. By keeping this material it would be possible to do testing to determine what it is at a later date if needed.  There are no makers marks or copyright marks of any kind on this bottle.  It is likely that it held alcohol of some kind, possibly wine.

Conservation Tip:  Material cleaned (removed) from an object should be stored in a sealed container made of inert material such as glass to preserve the contents in as original condition as possible.  In the example above I used a glass container with a glass top and a rubber washer to hold the glass stopper in place.  The rubber washer is not exposed to the material inside.  It was purchased at a local dollar store and cleaned with the soap mixture, rinsed with distilled water, and dried before use.