: Preventive Conservation

This week is Chemistry Week and our Preventive Conservation team got involved. Two local high schools (St Teilo’s Church in Wales High School and Cardiff High School) were invited to participate in a workshop with live demonstrations and hands-on activities.

We organized the workshop in a collection store and one of our analytical laboratories at National Museum Cardiff. Neither space is laid out for large numbers of people and it’s always a bit of a squash. But once we had squeezed the last of the year 12 and 13 students into each room and closed the doors, there was no escaping the exciting world of analytical chemistry.

The students learned about Wales’s largest and most important mineral collection, the challenges of caring for it, and some of the analytical tools that help us: X-Ray diffraction (XRD), gas detection tubes, infrared spectroscopy (IR) and Nuclear Magnetic Resonance (NMR). The XRD is part of the National Museum's own analytical facilities, operated by Tom Cotterell and Amanda Valentine-Baars in the Mineralogy/Petrology section. The other two technologies are covered by the curriculum and the students enjoyed the opportunity to prepare real samples, analyse them and interpret the results. To them, this made the subject a lot more real than just learning about them from books. It was also important that the analyses were undertaken not simply as a method per se, but in the context of answering genuine research questions at the museum.

What does chemistry have to do with the care of collections? We undertake our own research on objects and specimens in the collections, and we collaborate with researchers at universities. In addition, the act of preserving our common heritage often throws up problems, as objects degrade and conservators need to work out why, and how to stop the degradation.

Often we cannot do this on our own, in which case we work with partners to investigate, for example, the corrosivity potential of indoor pollutants and their effect on mineral specimens in storage at National Museum Cardiff. These partners include Cardiff University’s Schools of Chemistry, Engineering and History, Archaeology and Religion (Conservation Department).

One of these collaborations sparked yesterday’s schools engagement project, run in conjunction with the museum's Conservation and Natural Sciences departments and kindly supported and funded by the Royal Society of Chemistry (South East Wales Section). The Royal Society of Chemistry provided an entire bench full of portable analytical equipment for the day, which the society's Education Coordinator, Liam Thomas, set up in the Mineral Store. Because of the interdisciplinary nature of the project, additional support came from Cardiff University’s School of Earth and Ocean Sciences.

Find out more about care of collections at Amgueddfa Cymru - National Museum Wales here.

This week we managed to combine cleaning floors with a fitness routine and aroma therapy.  Who said housework can't be Fun!

Hannah Glasse, writing in her 18th century books ‘Servant’s Directory ‘ and ‘Housekeeper’s Companion’, advised using green herbs to clean wooden floors.
We couldn't resist having a go and it just happened that the floorboards in our 18th century Kennixton farmhouse required a bit of attention.

Like us today in the conservation team, wetting floors to clean them was considered to be a bad idea in the 18th century. It would introduce damp into the house and excess water could damage furniture and precious soft furnishings and carpets. 
Hannah recommended taking green leaves of Tansy, Lemon balm, Mint and Fennel, all of which we have growing in abundance in the cottage gardens. The herbs are then strewn across the floor and rubbed in with a broom.  The oils are released and nourish the wood, while the moisture activates the dirt, which is then taken up by the leaves.

We left the floor to dry overnight before sweeping up the debris the next day. Hannah then recommends polishing the floor with a dry rubbing brush, which should bring the wood up to a fine brown colour, just like mahogany. 

The herbs would also impart a sweet smell creating a natural air freshener. An added bonus for us is that the herbs Hannah recommended are also natural pest repellents that we normally dry and use throughout the cottages to protect our woollen textiles from moth or carpet beetle attack, so hopefully the lingering aroma will also deter pests from making a home.

It worked! All that Hannah promised came true. Our wooden floors appeared darker and shinier and the smell was amazing, we’ll definitely be doing this again.
 

Nothing lasts forever, not even in your favourite museum. The job of the conservator is to preserve the national collection but decay is all around us. Sometimes it feels like being a surgeon on an intensive care unit. Fortunately we do have a lot of science and technology to help us.

I have recently written about how we refurbished a collection store because corrosive gases being emitted from wooden cupboards caused some metal objects to show early signs of decay. In this blog I want to walk you through the science and analysis behind this project.

Iron rusts, every kid knows that. Leave a nail out in the garden and within weeks, days perhaps, you will notice it develops a lovely orange colour; given enough time, some moisture and oxygen it will eventually become flaky, friable and disintegrate. What happens when iron rusts? Iron atoms react with oxygen and water molecules, leading to oxidation of iron. The result are hydrated iron oxides, a small family of minerals commonly called rust.

Rusting iron has long been a bane of humanity. The Forth Bridge has to be repainted over and over again because it didn’t it would rust and collapse into the Firth below. The same is true of our own Menai Suspension Bridge here in Wales. Wales was the place for the invention of a rust-proofing process for household products made of iron. In the late 17^th Century, Thomas Allgood of Pontypool developed a coating for iron involving the use of an oil varnish and heat. This process was called ‘japanning’, as a European imitation of Asian lacquerwork. Pontypool Museum has lots of information about these old local industries on its website so please visit there if you would like to know more.

National Museum in Cardiff has a collection of Welsh japanned ware which was largely acquired during the early years of the National Museum. Many of these objects do not consist of iron alone: lead, tin, copper and zinc all feature in varying proportions in different parts of some of the objects. Complicated parts, such as handles and bases, were parts made from softer metals or alloys. We can find out what materials an object is made of using a completely non-invasive technology called X-ray Fluorescence (XRF). XRF directs X-rays towards an object and analyses the X-rays that bounce back. As different elements have their own, unique X-ray fluorescence which the instrument can identify and even use to quantify the elemental composition of objects without having to take a physical sample.

The problem for the museum conservator is that many of these metals, too, corrode under certain circumstances. In the case of the objects which were subject to the previous blog the corrosion of parts with a high lead component was accelerated by the high organic acid concentration within the old storage cupboards. A number of analytical tests exist for identifying and quantifying organic acids in air; we used small discs with an absorbent material that were exposed to the air in the store (both inside and outside of the cabinets) and later analysed in the lab. The results of this test showed that the concentration of acetic acid was 623µg/m³ (250ppb) inside the cabinets and 19µg/m³ (8ppb) in the store, and the concentration of formic acid 304µg/m³ (159ppb) inside the cabinets and 10µg/m³ (5ppb) in the store.

We know that both acetic and formic acids are emitted by wood, and both acids can react with various metals to produce, in some cases, some impressive corrosion products. Clearly, the concentrations of both acids were higher inside the storage furniture than in the store itself, giving us a massive clue that the problem was caused by the cabinets and not air pollution entering the store through the air conditioning system. The fresh air supply into the store, on the other hand, kept the concentration of pollutants low in the store itself.

Corrosion and decay comes in many forms, and we also use other technologies to help us identify corrosion products. Of these more in a future blog. In the meantime we are continuing to eliminate the sources of corrosive substances from the museum to help preserve the national collection.

Find out more about care of collections at Amgueddfa Cymru - National Museum Wales here.

Museums are outgoing institutions. Our doors are open to anyone, regardless of age, level of ability, ethnicity, and so on. We are happy to welcome everyone and will do our best to accommodate people’s needs and interests. Many museums are free because we do not want low income to be a barrier for visiting. AC-NMW’s Conservation Department has recently stepped up its outreach programme. We organise regular Open Days (the next one is on 25^th October), talks, behind-the-scenes tours, schools activities etc – preservation of the museum’s objects is an important part of what the museum does and quite rightly forms part of the museum’s public offer. So much for museums.

Now for the visitors. Why do people visit museums? Because they have travelled here and are trying to get a sense of place. Because they want to spend some quality time with friends/family. Because they have a specific interest. There are many reasons, most of which indicate that visiting museums is a leisure activity that reflects what people are interested in and how they like to spend their spare time, just like reading, cycling or watching box sets on TV. Jehra Patrick summarised in her blog some of the motivational identities of museum visitors compiled by John H. Falk. She also suggested that to get people in the doors, museums should stop telling them why they should come and start asking them why they do. 

Last year we asked visitors whether they would like conservators to be more visible in public spaces. The feedback was a resounding and emphatic ‘YES!’ by 90% of our visitors. We heard the shout and started scheduling more of our regular maintenance work during public opening hours both at St Fagans and in the city centre. Again we checked with the visitors and, low and behold, they said they would like to see conservation in action even more often. Visitors are insatiable, one might conclude. Or are we really that good? Either way, it was all good news, the new way of working was a success, we congratulated ourselves, lots of shoulder padding going on etc.

Now a dear friend asked recently: ‘do visitors like to talk to museum staff about Conservation, or do they just like to talk to staff?’ Jaw drops. Had we not asked visitors whether they would like to speak to conservators? And had they not told us that they did? Well, yeah – but what we didn’t ask was whether it mattered that they spoke to conservators. Or anyone else.

It is certainly clear from experience (I am now straying from hard data into anecdotal evidence) that many museums visitors like to talk. When we work in the galleries or historic houses there are endless opportunities for chatting. We, as staff and volunteers, make it as obvious as possible that we are approachable and happy to talk. Many visitors use the opportunity to do just that: ask questions about our work, about the objects on display, or tell us about a moth infestation they once had in a carpet. The latter does not tend to happen randomly – pest management is one aspect of our work.

However, there is certainly a difference between being a member of museum staff (visitor perception) and being a highly skilled individual with years of experience who is fully subscribed to the museum’s policy of inclusivity, enthusiastically raring to inform visitors about the museum’s efforts in heritage preservation (conservator perception). It is interesting to note that, when working in the galleries, conservation is not the only thing we talk about. We also find ourselves giving directions, answering questions about objects on display, telling people about other cultural venues in South Wales. And – for reasons of liability – avoiding giving advice on moth infestations in domestic carpets.

Does it need a conservator to answer general enquiries? Of course not, and the museum already has additional staff for just that sort of thing. Should a conservator therefore refuse to answer such questions? Again, of course they should not – courtesy and politeness alone should be reason enough to attempt to answer any question.

Visitors cannot be expected to distinguish between different members of museum staff or volunteers. I, as a conservator, have to be aware of this and be prepared to answer any question asked of me as best I can to create experiences that fulfil visitor needs. It is also clear that visitors have expectations of their museum experience that often differ from what staff believe the offer is. The route to success for me, as member of staff, is therefore to be flexible and acknowledge the visitor’s diverse interests and needs. And to ask the right questions.

Find out more about care of collections and Preventive Conservation at Amgueddfa Cymru - National Museum Wales here. 

Keen-eyed visitors to National Museum Cardiff may have noticed recently the presence of little pieces of black card in some of the galleries. These pieces of card are there to serve an important purpose: to gather dust. And they are not only in the galleries; we distributed some in collection stores, too.

We want to know just how much dust is building up in parts of the museum. We also want to know what kinds of dust we are dealing with. We can only get this information by monitoring dust deposition.

So what’s the big deal with dust? What harm can a bit of dust do?

Well dust is unsightly from an aesthetic point of view. In addition, it can actually damage the museum’s collections. When dust sticks to a surface, it really sticks to it. Some types of particles can scratch and mark the surface of objects as they act like an abrasive; this is why when we clean museum objects we are extremely careful not to cause any scratching. Dust also attracts moisture, and surfaces covered in dust are at risk of wicking moisture onto the surface of object which can cause damage. This is especially the case on those horrible rainy days.

So both cleaning the dust and leaving it on risks damaging objects, but by monitoring the dust we can ensure that those risks are kept low and your enjoyment of the exhibits remains high.

Stefan is a student at Cardiff University and currently undertakes research for his MSc in Care of Collections at National Museum Cardiff in conjunction with the Preventive Conservation team.

Find out more about care of collections and Preventive Conservation at Amgueddfa Cymru - National Museum Wales here.