Articles tagged with: conservation

Cleaning and Care of Historic Metal Objects

on Tuesday, 16 April 2019. Posted in Conservation

What is corrosion?

Corrosion that appears on metal objects is a chemical reaction where the metal is trying to return to its natural mineral state. This often appears as green deposits on copper and red/brown deposits on iron. The main cause of corrosion on metals is a humid environment.

How do you remove corrosion?

Some corrosion is good! If your metal object has a thin dark layer on the surface this may be acting as a protective barrier from further break down of the surface. This is called patination or tarnish.

We would recommend you avoid trying to remove heavy build-up of corrosion yourself. This often needs to be done under a microscope in controlled conditions. Excessive use of polishes and chemicals (I’m including Cola and Ketchup in this!) could remove original surface so that details and decoration are lost. For example, you would no longer be able to identify the date of a coin if the surface was abraded and removed. It can also cause the metal to thin and wear down silver plating.  Chat to a conservator if you are concerned about the corrosion build up on your object or want to find the most suitable cleaning regime.

How do I care for the object in the future?

One of the most damaging things to metals is the oils and acids from our fingers, which can etch in to the surface of the metal. We would recommend always wearing cotton, nitrile or latex clothes when handling metal objects. This will also reduce marks and therefore the need for cleaning.

Giving the metal object a dust with a soft micro-fibre cloth or soft hog or pony hair brush will help prevent build-up of dust and dirt. Buffing or coating the surface with wax should rarely be necessary and should only ever be attempted after removing dust and dirt. Depending on the object and environmental conditions a wax or lacquer may be applied to protect the surface from humidity and prevent future corrosion development.

Store in an environment with a low humidity and pack using inert materials such as foam or acid free envelopes. A hoard of coins recently in conservation was packaged in individual acid free paper envelopes, sealed in a Polypropylene plastic box (recycling number ‘5 PP’) to provide a controlled environment and a sachet of silica gel to reduce humidity.

So, remember, avoid the cola and gently brush your objects to maintain a healthy patination!

Kayleigh Spring, Conservator, Conservation and Museums Advisory Service

Wiltshire Conservation and Museums Advisory Service is based at Wiltshire and Swindon History Centre. We preservice the Wiltshire and Swindon Archives and provide support to museums, heritage organisations and individuals to care for and conserve historic collections and meet professional standards.

If you have items in need of a little TLC see if our conservator can give you hints and tips for cleaning without damage, advice on storage or a to get a quote to have them repaired.

We hold regular conservation surgeries at WSHC from 2 – 4pm on the second Thursday of every month. The next one will be on May 9th. Book you appointment by calling 01249 705500.

Behind the scenes at Chippenham Museum: Reconstructing Roman Ceramics

on Wednesday, 06 March 2019. Posted in Archaeology, Conservation

A number of Roman finds were recently uncovered in the back garden of Marc Allum, a specialist on the Antiques Roadshow, during excavations organised by Chippenham Museum volunteers Clive Green and Mike Stone.

Mr Allum kindly donated the finds to Chippenham Museum. The Friends of Chippenham Museum worked hard to raise funds for the conservation of one of the finds - a fine Samian ware bowl - and conservators at CMAS were privileged to undertake the reconstruction of this beautiful piece.

The Samian ware is an example of a Dragendorff type 37 bowl, suggesting it is Gaulish dating from c. AD 70-130. The bowl has intricate decorative panels with repeating motifs of Gladiators battling wild cats and a more risqué scene thought to depict the deity Bacchus.

The Samian ware was found in 51 fragments forming almost half the bowl. Due to the fine nature of the form and decoration it was decided to fully reconstruct the piece, replacing lost areas to give more complete impression of its original form.

The conservator worked hard to piece together all the fragments. Interestingly the way the ceramic had broken into layers reveals its method of construction. Samian ware with such detailed patterns was formed by pressing clay into preformed moulds. The ceramic has split along the lines of the layers that were built up.

Graham Taylor of Potted History (@Pottedhistory) has created replica moulds for the vessel and its decorative features in order to produce a facsimile using the same techniques.

Once the form of the original ceramic was determined it was possible to create an accurate profile from base to rim using measurements of the thickness of the ceramic fragments and the diameter of the base and rim, comparing these with known examples.

The profile was used to form an accurate core in clay to which the original ceramic could be secured. Plaster replacement fills were then ‘spun’ using the profile as a guide. It was decided to only replace larger areas and those smaller areas required for strength.

Archive to Survive!

on Tuesday, 20 November 2018. Posted in Archives, History Centre

My name is Annette and I am an Employer Engagement Officer with Wiltshire Council  working on a program called Building Bridges. 

Building Bridges is funded by the European Social Fund and the National Lottery, through the Big Lottery Fund.”

Several weeks ago, Wiltshire & Swindon History Centre & Building Bridges set out on a journey of discovery and learning with five would-be archivists with a love of all things past. You could say a real ‘Throwback Thursday’ as this is the day we came together to indulge in something we all love: history.

I can’t believe we have nearly come to the end of our first but I hope not last ‘Archive to Survive’ project.

After attending a learning symposium facilitated by Wiltshire Museum & Heritage Service and hearing a presentation from The Museum of London and the work they were doing with Autism in Museums I was buzzing - I couldn’t wait to do something similar.

Lucky for me I had already formed a working relationship with the fabulous Heather Perry -Conservation & Museum Manager who was nearly as excited as me, and completely on board.

We decided we wanted to target our project at those who may have found it hard to gain paid employment due to anxiety, depression, or other barriers. We wanted to promote confidence and skills learning that would support their journey, and give them a sense of wellbeing and inclusion. 

So along with my Building Bridges partners in crime Lorraine, Laura and the lovely Sophie, Conservator (Archives) at the History Centre, we set about putting our plan into action. 

If you are reading this it is possible you will know that in Wiltshire & Swindon we have an amazing purpose-built facility that holds the county wide archives. What you may not know is that the public can come in and research things from family histories, to who lived in your house 100 years ago. To do this every document held at the centre needs to be catalogued and this is where we came in.

We wanted to offer an opportunity for a group of people to come in and work with trained professionals to learn all about maintaining and cataloguing this amazing resource. Preserving it for future generations and so Archive to Survive was born.

We recruited five like-minded participants with a love of history and our journey of learning began back in August. Since then we have come together every Thursday and have been building on our confidence and skills, and form new friendships.

The group looking at one of Community History Advisor Ian Hicks’s favourite items in the archives (the Seymour Pedigree ref 1300/376L)

Details from the Seymour Pedigree (1300/376L) taken by participant Richard © R. Taylor 2018

Thinking of doing a work placement? My experience with CMAS

on Wednesday, 29 August 2018. Posted in Conservation, History Centre

I can’t believe that the first year of university is over! It goes so fast and with so much information it can be a bit overwhelming, but trust me, all that hard work and studying will pay off. The Conservation of Objects in Museums and Archaeology undergraduate course at Cardiff introduced me to a whole new world of practical science, as well as in-depth theory, of conservation materials and specialised equipment, such as x-ray and air abrasion machines. By the end of the year I felt pretty confident with the concept of conservation but was still nervous on how to actually apply the theory with real, archaeological objects; in a true work environment.  This is where a work placement comes in. My first-year placement was at the Wiltshire and Swindon History centre, as part of the Conservation & Museum Advisory Service (CMAS), a commercial business which deals with issues both in museums and in public collections.

Although it can seem daunting at first, this experience is essential for developing those practical skills and applying the theory with real, archaeological objects, as well as understanding the treatment of different materials and the ethical choices conservators must make; focusing on what’s best for the object and adjusting treatment plans with the client’s wishes accordingly. Keep in mind that work experience is for your benefit, so don’t panic when you have millions of doubts and questions because the people you work with are there to help you (even if you ask questions every 5 mins).

So anyway, onto the actual conservation, hooray!

First things first, you will need to assess the object just by looking at it and writing up a condition report, which simply states any observable issues with the object. The majority of my time was spent working with a Roman ceramic oil lamp in the shape of a foot! Quite a fun object from Chippenham Museum, but as you can see there is a bit of a messy application of adhesive around the centre of the lamp where it has broken in two and was re-joined.  There were also scratches, dust and cobwebs on the inside, layers of red dirt/soil on the surface as well as white flaking corrosion (see figures 1-4).

Before treatment:

Figures 1-4

Ok, so the lamp required a good clean and that adhesive definitely needed to come off. Ultimately, the decision was to completely remove the adhesive and undo the join so that I could re-attach the two pieces with a better, cleaner join.  In order to remove the adhesive, I needed to work out what solvent it was soluble in. For this, I took small samples of the adhesive from the lamp by slicing off some of the softer areas with a scalpel, under a microscope.  I then put the samples into a petri dish and tested them with different solvents (see figures 5 & 6).

Testing solvents on the adhesive:

Figures 5-6

After about 30 minutes, I could see which solvent made the adhesive go soft and rubbery. The process of removing the adhesive required quite a lot of patience as the it didn’t want to budge; a scalpel was used to remove larger chunks of the adhesive and a poultice was placed around the join. A poultice was a way of creating a solvent environment to help loosen the adhesive and separate the two pieces. 
 *Just to give you an idea of the tools used in this process, I’ve taken a couple of photos for reference.

Figure 7 From left to right – pin vice, plastic tweezers, scalpel, wooden stick and cotton wool

Figure 8

In conservation, we usually make or own cotton swabs by using a bamboo stick or cocktail sticks (depending on what you’re working on) instead of regular, pre-made cotton swabs.  Making your own means that when the cotton gets dirty it can be easily replaced and the size of the swab can be varied so you can get into the small nooks and crannies that need a good clean. It also means that we aren’t throwing away millions of cotton swabs and being more environmentally friendly.

After many tries, the poultice wasn’t loosening the adhesive, so I went in with the scalpel and pin vice to try and dig out some adhesive in the join. Another poultice was then left on for a couple of hours. When it was removed I was able to gently pry apart the two pieces (finally!) and clean the new surfaces (see figure 9).

Seal of Approval

on Monday, 23 July 2018. Posted in Archives

Archives are regarded, quite rightly, as vital sources of information about past lives and times, and are pored over for the fascinating details that they offer. However, in the quest for knowledge it is easy to overlook the format and appearance of the documents, which are also informative, but are worthy of consideration and appreciation for their style and artistic achievement. A good example of this is seals, which were used to validate or authenticate documents, much as we might provide a signature or enter a PIN.  A soft material made of beeswax with tree resin and pigment that was pressed into a metal matrix onto which image and text was engraved, to make an impression. Usually the seal would have writing around its edge (known as the legend) which was often in Latin. They might identify the owner, or be relevant to the image. One of my favourites, in The National Archives, appears on the seal of a lady, ‘Love me and Lyve’.

Why are they important and so deserving of such attention? Because they are examples of the skill of the engravers who made the moulds or matrices, which produced exquisite miniature works of art. This small scale medieval sculpture complements the work of masons, carvers, painters and other craftsmen in buildings, statues, paintings and devotional and personal objects that survive from the Middle Ages.

The choice of motif was a matter of personal taste surviving from a time when people had few personal items. They are revealing about the owner: their social status, indicated by the use of heraldic symbols, emphasising his or her power and authority: their occupation, by an image of the tools of their trade: or their personality and mindset, by devotional motifs indicating their piety, or amusing images suggesting a sense of humour. Wit, sentimentality, and popular devotion, all appear in the designs the seals of individuals below the elites. Delight in the absurd and the burlesque, such a hare blowing a horn while riding on the back of a dog and humorous punning designs and pictograms were commonly displayed. Images of saints with their emblems, such as St Catherine and the wheel on which she was tortured, a pelican in its piety, pecking their breasts to feed their young, were also popular designs. 

I will be giving an illustrated talk on this subject, entitled Good Impressions: Seals from the 13th-20th centuries, at the History Centre on Thursday 9 August at 10.30. Tickets £4.00.

No the History Centre is not trying to compete with the Whale and Dolphin Conservation Society, also based in Chippenham, and taken on a wider brief in the preservation of the Natural World. This is about the seals, archival not mammalian; the lumps of beeswax impressed with intricate and elaborate designs that authenticated legal documents. Relevant in a time when only the few could read or write their names, the conservative nature of the law means that they continue in use today; if reduced to the ignominy of a self-adhesive red circle stuck alongside the signatures on deeds.

The Conservation Team Visit Salisbury Museums

on Friday, 08 June 2018. Posted in Conservation, Museums

Conservators from the Conservation and Museum Advisory Service at the Wiltshire and Swindon History Centre have been out and about visiting museums in Salisbury. Our time visiting local museums is used primarily to provide advice and guidance on specialist aspects of caring for a museum collection. Often this involves walking a fine line, balancing the need for conservation and long term preservation of a collection with the very important need for a museum to display and allow access to its collection. For the conservation of many objects the ideal storage location would be a cold, dark, sealed box. However this is obviously impractical, not only for any museum to achieve, but is contradictory to the reason for preserving collections: allowing people to see and access items for a long time to come. Collection care is therefore a balance of risks, between what is best for the collection item and how the item can best serve the needs of the museum.

Arundells, the former home of Sir Edward Heath KG MBE, Prime Minister and Statesman, houses a diverse collection. The museum maintains Sir Edward’s home as it was at the time of his death and so collection items such as a grand piano, fabulous art works and gifts from his state visits sit side by side with yachting photographs, satirical cartoons and even a very 70’s disco shirt!

The collection item most memorable from our visit was the hand-painted silk wallpaper which lines the visitors’ route up the staircase to the first floor. The wallpaper, a gift to Sir Edward from his staff, was installed in the house in the 1980’s.

Wallpaper at Arundell 01

Keeping the location of the wallpaper at Arundells is crucial as it was purposefully created for the location chosen by Sir Heath himself. To remove the wallpaper and hide it away in dark, cold storage would irretrievably reduce its historical value. So the question is how best to preserve the wallpaper on permanent and open display in the museum?

wallpaper at Arundells 02

Historic houses often have collection items (otherwise known as fixtures and fittings), such as wallpapers, curtains, carpets and furniture which are required to be maintained in their normal settings. Curtains can best be understood as curtains if they continue to frame a window and wallpaper is best understood if it remains lining a wall. Contrary to our conservation ‘dark box’ a controlled environment is particularly difficult to maintain for fixtures and fittings on permanent display in their original locations. Particular threats to these collections are high light levels from windows and internal lighting, warm conditions from internal heating and pests.

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