: Gwasanaethau Casgliadau

Dropping a rusty nail into a glass of Coca Cola will clean it in a matter of hours. We have all heard that one. Other drinks manufacturers are available, and alternative liquids will do the same job: lemon juice, vinegar, even salad dressings.

What causes the nail to go rusty in the first place is corrosion. Rust is the product of the corrosion of iron, and I bet my favourite chemistry book that you will have seen rust somewhere. Many other metals can corrode, too: aluminium, zinc, lead, copper etc. Corrosion is electrochemical oxidation; it usually needs water and oxygen to corrode a metal. If you drop a clean nail into a salt solution (electrolyte) it will start rusting within hours – the iron loses electrons and gains oxygen. The acidic liquids in the first paragraph appear to have the opposite effect but, in fact, dissolve the rust rather than convert it back to the base metal.

This blog is turning into a mixture of a cooking recipe and a heavy science article. What on Earth does all this have to do with museum collections? After all, we don’t allow food consumption in our galleries and stores so where does the vinegar come from?

Well, believe it or not we do have vinegar in the air in the museum. You do, too, at home. Along with formic acid, acetic acid (the thing that gives vinegar its zingy taste) can be air borne in indoor environments. Both acids are considered indoor pollutants. Hardly detectable outside, in certain conditions they can accumulate inside buildings – and then cause corrosion. Indoor air pollution has recently been in the press, but we are talking here of risks to museum objects, not health risks to people.

Where do these substances come from? Wood readily off gasses acetic and formic acids. Book cases, furniture, floor boards, the wooden boards your walls are made of – they all emit these substances. Normally, this is not a problem; we all ventilate our houses, and normally we don’t keep objects at home long enough for corrosion to be a problem. Or is it? My mother still polishes her silver regularly and keeps it safe – in a wooden cupboard. Make of that what you want. Perhaps she enjoys polishing.

Your favourite museum has a lot of metal objects in its stores. And we are, of course, in the business of keeping objects safe not just for short periods of time, but for centuries. Over long periods of time we do notice corrosion on metal objects even if they merely sit on a shelf. We could go round cleaning these, like my Mum does, and give them a polish from time to time. Time consuming, I hear you cry. You lose a teeny tiny part of the surface each time you polish it, I hear you scream. And wouldn’t it be better to prevent corrosion in the first place, I hear you shout.

Right you are, I respond. After all, this is Preventive Conservation. We can measure the concentrations of air borne acids with good accuracy. We also know the sources of these acids. So when we detect signs of corrosion all we need to do is some simple investigating and – hey presto – come up with a mitigation plan. In some cases this might mean replacing old, wooden storage furniture. In others, we might have to introduce ventilation to a store to prevent pollutants from accumulating to harmful levels. Either way, the collections will benefit.

At National Museum Cardiff we have done both, and with good success. We have recently refurbished two stores with the sole aim of reducing indoor pollution. This was not cheap, but it is more cost effective than constantly polishing the silver ware - over and over and over again. It is because of these constant collection care improvements that we can say, hand on heart, your heritage is safe in the museum. And why we only eat fish and chips without vinegar in the museum. Only joking – food is still banned. Don’t let me catch you with any chips in the galleries!

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

Between 20 June and 4 July, our popular Evolution of Wales galleries will be closed while we undertake some essential maintenance work.

For these two weeks, visitors will not be able to access areas showing the introduction, Big Bang, Carboniferous forest, dinosaurs, mammoth or the Ice Age animals. Other galleries remain open during this time, including the Diversity of Life gallery (with lots of birds), the mineral collection and all the natural history galleries with the British woodland scene, basking shark, hump back whale skeleton and our new exhibition Wriggle! The art galleries upstairs are also open, unaffected by the maintenance work.

The work covers improved care of the collections and sustainability of the building, including:

1. Changing the gallery lighting to LED, to reduce electricity consumption, our carbon footprint and costs. LED lighting gives off less heat than conventional lighting so the air conditioning system will work better - it’s better for the items on display, because keeping a stable temperature helps maintain the condition of the objects. LED lighting also reduces future maintenance costs, and changes to the lighting will make the galleries brighter in some places.
2. Improvements to the fire alarm system so it's better for the collections, the building, staff and visitors.
3. Upgrading video screens from CRT to HD LCD with touch button interactive controls. This will improve video content delivery, reduce maintenance costs and provide a contemporary aesthetic to the gallery, making units more streamlined.
4. While the galleries are closed curators will be able to secure some of the items that have become loose in the cases, thus improving their long-term care. They will also clean the displays thus reducing the risk of potential pest infestations – pest management is vital to the care of museum collections.
5. Finally, installation of the new life-sized recreation of the new Welsh dinosaur, Dracoraptor hanigani as part of the dinosaur display.

Don't worry no violence was involved. It was the turn of Llainfadyn this week, our quarrymen’s cottage from Gwynedd, to receive a clean and make over from our Historic Interior and Conservation Volunteer team. It was a big task so thanks to everyone involved. This included stripping the beds and giving everything including the feather mattresses a good airing and beating to remove a winter's worth of dust and dirt. As long as the textiles are strong enough this is still a very effective method of removing grime without the aid of modern appliances.

We also held a competition between a modern broom and a traditional one made from hazel twigs (that all important witches’ accessory at Halloween). To help protect the collections on display it's important we try and reduce the amount of dust and dirt being brought into the houses by our thousands of visitors each year. Our first line of defence to achieve this is the cobbles outside, these help dislodge the grit and dirt from peoples' shoes before they even enter the building, but for these to work the cobbles need to be clean and not clogged up with dirt. So one of our first important tasks was to clean the stones outside.

So which broom won? The traditional of course, with its long twiggy brush it was the best at dislodging the dirt from between the cobbles. This job would certainly have been an everyday task for most households in the past.

Our second line of defence to keep the dust down is the rag rug, often found in cottages of this period. These were made from scraps of material or worn out clothes and blankets, so as well as providing much needed comfort and colour they were great at trapping dirt. They could then be picked up, taken outside and beaten with a carpet beater to remove the grime. We are currently making one for Llainfadyn, unfortunately the odd hail storm meant that Jane and Emma had to find seats by the open fire to carry on their work.

Sorry about the awful pun in the title. But, yes, it's that time of year, the sun is out, spring's officially here and it's getting warmer. Fantastic you may say, but for our Conservators and Volunteers a new battle is about to begin! As well as our lovely lambs and piglets, less desirable creatures are stirring. These are the insect pests, such as moths, carpet beetles and woodworm, that if left unchecked would quite happily eat our museum and its collections!

This week the volunteer conservation team were introduced to the enemy. In the natural world these insects perform an essential task, but in the confines of our historic houses, or anyone's home in fact, they can cause untold damage especially to items made from wool, fur, feathers, leather, paper and wood.

We have decided to go for a two-pronged attack. The first is to re-introduce traditional deterrent methods. Last year we worked with the gardening team collecting and drying a range of aromatic plants such as Tansy, Wormwood, Rue, Rosemary and Lavender traditionally used to deter insects. From the selection grown in our gardens we have created the extremely potent St Fagans blend.

Now we are devising ways to deploy our deterrent in sufficient quantities that might have an effect. For this we found tights ideal for the task! Yes, that's correct, tights. These are especially useful for items of clothes hung up on display, they enable us to place the aromatic plants in the more inaccessible areas of a garment, such as down sleeves!

The second method of attack is of course good old fashioned housekeeping. Spring is the time to open up the house after a long winter and give everything a good clean, or in our case a good beating.

The recent Ivor Davies exhibition Silent Explosion at National Museum Cardiff sparked an explosive partnership project. The mMseum’s Learning Department and artist Claire Prosser worked with Albert Primary School in Penarth on an art project inspired by Ivor Davies's work. Ivor Davies grew up in Penarth and went to Albert Primary School as a child, where he witnessed the war and air raids on Cardiff. Some of his early work is based on these experiences.

The year 5 pupils visited the exhibition at the Museum, which reflects some of those childhood experiences, and made sketches and collages. One of the boys had re-drawn Ivor Davies’s drawing of enemy planes being caught in search lights, and added an additional plane. Ivor Davies himself came to visit the school at the end of the day of walks and signed this drawing and many others, much to the delight of the pupils.

On walks around Penarth the pupils discussed conservation, death and decay with Senior Preventive Conservator Christian Baars. It is not easy to conserve art that was created to be ephemeral. The pupils learned how organic objects, and even rock, are not everlasting, and instead part of a big circle of life, death and resurrection in new forms.

The role of any museum, in essence, is to preserve objects by halting that circle at a particular point. Whether this is in line with the artist's intentions, and how museums deal with this conundrum, was part of a "Conservation Conversation" at National Museum Cardiff a few weeks back. Curators, conservators and artists were involved in the discussion then. Bringing this theme closer to year 5 pupils proved entirely possible, as they enjoyed learning about how museums preserve objects while thinking about how it is really difficult to make anything last for centuries.

This interdisciplinary partnership project was also a joy to work on for staff, most of all the preventive conservator, as it brought together so many aspects of art and science.

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