Standen

What goes on behind the scenes at Standen House, an Arts & Crafts family home


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How we use blue fabric to monitor light

You might have seen these around the house. They’re called blue wool dosimeters and we use them for keeping an eye on how much light exposure the house gets over a year. In February we have to collect them in and send them off to be analysed.

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A blue wool dosimeter in situ in the north bedroom (NT/Victoria Witty)

They are rather low tech, but very clever. They are made of picture mount and pieces of specially dyed (blue!) wool, the latter which is known to fade at a certain rate when exposed to light.

We use them to see how much light falls on certain objects or rooms over a whole year. As a registered museum we need to try to keep to museum standards of light exposure to our collection:

  • highly light sensitive rooms/objects = 150,000 lux hours
  • moderately sensitive rooms/objects = 600,000 lux hours

Blue wool dosimeters allow us to see how much cumulative light the house and collection has been exposed to over the year and if we need to adjust how we show the house.

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Results of the blue wool dosimeters from around the house 2015-6 (NT/VW)

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The back of a blue wool dosimeter – important information for when they are analysed (NT/VW)

You can see below that the aperture is smaller than the piece of fabric so when they are analysed there is something to compare the faded area against. We need to make sure that the dosimeters aren’t moved to make sure they give the most accurate information they can.

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This is what it looks like after a whole year out, just before we send it off to be analysed (NT/VW)

Sometimes, as they are wool, they get munched by pests – wool is a favourite food of carpet beetles and their larvae, woolly bears…

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We try not to let this happen! (NT/VW)

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Preserving Plastic

There was an interesting article in the Guardian recently about the difficulties that the V&A Museum are facing when it comes to preserving plastic objects: http://www.theguardian.com/artanddesign/2015/may/19/va-conservators-race-to-preserve-art-and-design-classics-in-plastic

The Blow Chair

The Blow Chair Image Courtesy of The Guardian

The rise in technology has led to the creation of new materials which are used to create art and objects, both decorative and every-day. However, we know very little about the longevity and the process as to how these materials will change. This has become apparent with some of the plastics in the V&A’s collection. Objects such as the Blow chair, designed in 1969, and the Stephen Willats Mini dress, also designed in the 1960s, are starting to degrade to the point beyond repair, and the only way to protect them to keep them in dark, temperature controlled stores.

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Stephen Willats Mini dress Image Courtesy of The Guardian

The common assumption with plastics are that they are a stable substance, when in actual fact they are very brittle. The reason plastic is brittle is because plasticers are used in the process to make it malleable. Unfortunately, plasticers have a habit of leaking, making the object sticky, attracting dust and dirt. This stickiness also makes it very difficult to clean as brushes and water only further damage the object. Plastics are also susceptible to changes in temperature, humidity and light, which can lead to discolouration, decaying to a powder, warping, cracking and shrinking – all the things that we try to prevent happening to our collections as a whole.

As plastic is still a relatively new material we do not know as much as we would like in order to prevent damage to it. This is why the V&A has partnered with Imperial College London to try to see how we can prevent further damage as well as its causes. With most other materials that can be found in historic house, there is a history of research that has gone into how we can best look after them.

Light damage to the Sofa turning it from Pink to Green

Light damage to the Sofa turning it from Pink to Green

Temperature, light and relative humidity are monitored both weekly and biannually. This ensures that we keep an eye on things that might be in danger of deteriorating and we can then assess how best to limit any damage. Humidity causes objects to shrink and grow that leads to stress fractures and cracks as can be seen on the cabinet at the Top of the Stairs. Light not only causes objects to fade but also causes threads to fray and eventually tear. Light also causes a chemical reaction whereas the object will actually change colour – like in the drawing-room where the rose-pink sofa has faded to a murky green colour.

Deep Cleaning the Mosque lamp in the Drawing room

Deep Cleaning the Mosque lamp in the Drawing room

As I mentioned a couple of weeks ago, (https://standennt.wordpress.com/2015/05/19/deceptive-dust/) dust is another factor that damages the collection as it discolours objects but also forms a hard surface which not only attracts more dust but is also very difficult to clean off without damaging the object.

This is why knowledge and a good cleaning routine are so important. We dust and vacuum the house once a day plus every object gets an annual deep clean every year. It is also why the house may seem cold or dark as we try to preserve it for the future.


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Filtering Light

Light damage to the Sofa turning it from Pink to GreenLight is one of the most damaging factors in conservation. Light damage is quite easy to spot as causes quite dramatic fading or bleaching but for other objects it can be even more damaging. For textiles like cushions and wall hangings light causes fibers to break down and eventually tear. For organic materials, like paper and animal based glues, they become brittle whilst vanishes and oils harden and flake.

Light falls across a spectrum and different ends cause different problems, such as Ultra Violet (UV), visible (which is the only part of the light spectrum that humans can see) and infrared radiation (which we feel as heat). The most damaging part of the light spectrum for historic collections is UV.

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The UV Film ready to go

Ideally UV levels should be at zero but it is impossible to prevent UV from reaching collections as it is present in both natural light and light bulbs. Fortunately the light bulbs here in the house do not emit too much UV but the windows and doors present another problem.

In order to prevent as much damage as we can, we follow a strict light plan by limiting the number of hours the blinds and shutters are open. we also use UV filters on all of the windows and doors.

UV filters are made up of a polyester film that absorbs and reflect UV. However it is not perfect and does let in some UV. UV film lasts between 10 – 12 years during which point air bubbles and cracks start to appear. We have recently had our filters replaced which was very interesting to watch.

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The UV Film being applied to the Half Landing Windows

Firstly the old film had to be removed which is rather simple – it is literally pulled off the windows and then any residue left on the glass is scraped off with a razor blade. The glass is then washed. The new film is then stuck on using water as its adhesive. it sounds very simple but the new film has to be tested before being applied to ensure it is up to the job and then it has to be cut to fit the pane of glass exactly. You can imagine in certain places here, like the windows on the Half landing, taking a long time!

 


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Environmental Monitoring…

Running a historic house involves lots of different kinds of work, which we divide up into daily, weekly and annual jobs. One of the weekly jobs is to monitor the light, humidity and temperature. If the levels are wrong, than the collection deteriorates and becomes permanently damaged.

The Sofa in the Drawing room that used to be pink...

The Sofa in the Drawing room that used to be pink…

Light is one of the main causes of damage in any house, not just historic ones. It can be quite easy to see some of the damage through fading of colors but this is really only an outwardly sign of deeper damage. A high amount of light activates the chemicals, that make up the color, to react and change. One of the best examples that we have here of this is  the velvet upholstery on the sofa and matching chairs in the Drawing Room – they used to be a bright rose-pink but are now green.

Light also affects the threads in fabric, causing them to break down and snap leading to tears and rips. Ever handled something that has fallen apart in your hands when you  pick it up? This is what can happen to fabrics like curtains, carpets and tapestries.

Humidity levels are different for every type of object. For example, the correct humidity level for metals is too dry for wood, which would cause the wood to dry out and split. If the humidity is too low, organic materials like leather and wood shrink, crack and even in extreme cases, break. If the humidity levels are too high, than organic materials swell and stick, like drawers in a desk. High humidity causes dampness which in turn encourages mould and fungi. It also attracts insect pests and cause metals to rust.

Temperatures has two effects on collections. It is directly linked to humidity levels, so if it is hot, then humidity levels will be low and vice versa. Low temperature, especially sub-zero ones, will cause objects to become brittle and crack, whilst high temperatures can soften and melt some materials.

Environmental Monitor

Environmental Monitor

It can be difficult to find the right balance between these factors, which is why we monitor them at least once a week. In order to attempt to prevent damage, we have set budgets. In every room, there are certain objects that have been deemed as at a higher risk than others, which is determined by several factors, their materials or their historical significance to the house. These are the objects that we measure off using an environmental monitor.

This measure light or lux levels, relative humidity (RH) and temperature. We record it manually and take action a level is too high or low. Light is the easiest to fix as we can adjust the blinds, which is why it can sometimes be a little bit dark at times. Humidity and temperature is a bit harder to fix as it often involves adjusting heating levels and putting out humidifiers/de-humidifiers.