Spot checks!

One of the most important things we do at Knole is keeping an eye on the environmental conditions in the Showrooms. We do this through a combination of ways. Our primary method is using individual monitoring sensors in each room that send a regular signal back to the office detailing the Relative Humidity (RH) and temperature in each space. By this method we can keep an up to the minute record of what’s going on.

Our regular ‘Hanwell’ environmental monitors. This one is in a storage space and is showing an RH reading of 58%, right where we want it.

However, because of our current project and the work going on to improve the lighting, conservation heating and all sorts of other things it means that we don’t have proper radio monitors in some rooms right now.

 

RH in some rooms sometimes reaches worryingly high levels. It’s essential to keep a good watch on what’s happening.

 

This means that our secondary method become more important and we have to do it more regularly. This method is using spot checks. Usually we go into each space in the showrooms and store rooms every two weeks to take temp, RH, lux and UV readings to make sure that our automatic monitoring is consistent with our handheld sensor.

While the sensors are gone in the second half of the house we send the intrepid Zena in with a hard hat and a monitor to take readings every week. This way we know what kind of conditions the historic showrooms are facing on a day to day basis in all weathers.

Zena taking readings in the Ballroom

Oh the humidity!

One of the most important elements of conservation is making sure that our collection has the best possible environment to live in. In a house like Knole this is very difficult. It’s a large building with no heating or other environmental control. This means that the house can be at the mercy of the elements. Humidity and temperature rise and fall with the weather with no way for us to control it.

Condensation in the Second Painted Stair caused by high humidity (RH)

As part of the conservation project at Knole we will be having special conservation heating installed in the showrooms here. Sadly for our visitors and volunteers this does not necessarily mean that the house will be toasty and warm in winter! The heating will purely be there to control the RH (Relative Humidity) of the rooms. Relative humidity is one of the biggest problems we face here at Knole. When it is too high it causes condensation to build up on vulnerable surfaces, attracts dust and makes a perfect home for mould. It can also create perfect conditions for all sorts of pests such as woodworm and deathwatch beetle. When it is too low it can cause some materials to contract and crack, veneers to lift and glues to fail.

Because of the importance of RH and temperature we have to keep a very careful eye on conditions in the showrooms. If there are particular anomalies such as high RH where it is usually lower we can investigate what has happened. Perhaps there is a leak or a heater has failed. Although we don’t yet have control over the showroom temp/RH we have been able to have some control in some behind the scenes areas at Knole. We have special humidistats in special stores that will react to the Rh in a room and turn on heaters when necessary.

 Humidistat in the storerooms.

The primary method we use to monitor RH is our Hanwell environmental monitoring system. If you visit Knole you may see the sensors dotted around the galleries.

Here you can see the Painting Store monitor. It has an LCD display showing you the RH and temperature at the time.

 

Each room has a box and each box is equipped with a transmitter that relays the information it’s gathering to a computer in the office. This then plots a graph that allows us to see trends and patterns in individual spaces.

Within the National Trust we try to aim for an RH level of 40-60%. This represents the amount of water vapour present in air as a percentage of the amount needed for saturation at the same temperature. Because National Trust collections are often so varied and in historic settings there is no perfect RH that is ideal for all materials but this range gives us the best chance.

To make sure we have the most accurate readings possible we also take spot readings on a regular basis. This involves taking a handheld RH/temp monitor into each space and taking an extra reading. This is a good way to make sure we are obtaining accurate information. This is also our primary method of keeping an eye on RH/temp in the part of the house currently undergoing conservation work ready to be opened again next year.

Here is Zena taking environmental readings in the Ballroom during the conservation work.

Knole suffers with frequent high RH which will be addressed when we have our new conservation heating. Until then we do what we can!

 

Listening to the Furniture

At the beginning of March this year Knole was visited by Nigel Blades, the Preventive Conservation Advisor for the National Trust and a team of researchers from the Polish Academy of Sciences in Krakow. They were here to install some pioneering technology in the world of heritage sciences. With the help of furniture conservator John Hartley they have attached acoustic emission (AE) monitors to some of the most important objects in the house. The basic principal of these sensors is to listen for otherwise imperceptible noises emanating from objects as they react to the changing environment around them. 

Some of the sensors have been attached simply by wedging plastazote (an inert spongy material) into a convenient crevice, whereas others required gluing by a furniture conservator (although a hairdryer was needed to speed the drying process in the freezing temperatures at Knole!). Using a combination of gluing, wedging, and tying all of the monitors have been successfully attached.  

John Hartley preparing the sensor mount (left) and the finished sensor (right).

Sensor wedged with plastazote into a convenient gap in the 17th century Gole table.

 

These monitors are designed to pick up the tiniest cracks and pops emitted by the furniture as it reacts to the environment around it. The relative humidity (RH) in the Showrooms of Knole can cause certain materials such as wood and metal to expand and contract as it fluctuates. It is impossible to tell how much the objects themselves are moving with the naked eye and so this AE method has been developed to help us better understand what seasonal variations in RH are doing to our collection. The sounds the equipment are monitoring for are so tiny they couldn’t hope to be heard without these specialist sensors. 

The monitoring equipment in the Spangled  Bedroom

 

Sensors have been attached to 4 objects in the house; the Gole table and a torchere in the Great Store and the Jensen table and a torchere in the Spangled Bedroom. Selecting these objects allows the researchers to compare the effects on similar objects in varying conditions. The Spangled Bedroom currently has no environmental control at all. This means the the temperature and relative humidity change with the weather conditions outside with no human intervention. The Gole table in the Great Store however is subject to environmental control which keeps the relative humidity below 65% at all times. 

The full setup on the Jensen torchere in the Spangled Bedroom.

 

The ideal conditions for a mixed material collection in the National Trust is between 40% and 65% although this is not always possible. Part of our long term conservation project at Knole is to try and install environmental control throughout the Showrooms so that the RH can be carefully controlled.  

Every room has an environmental monitoring device like this. The Spangled Bedroom one has been placed behind the table and is recording temperature and RH every 15 minutes.

 

The AE project will run for a full year from now and it will allow us to understand and better manage the change from an uncontrolled to an RH-controlled collection. The sensors and laptops will be left in their current positions permanently and will be checked remotely from Poland once a week to make sure everything continues to function properly. 

Furniture conservator John Hartley (left) and researcher Marcin Strojecki (right) discuss the placement of an AE monitor on the Gole torchere.

 

It was fascinating to see researchers and conservators of different disciplines come together at Knole to put this project together. Hopefully it will yield some interesting results!

 

Thanks go to Nigel Blades and everyone on the AE project team for providing the information and pictures in this weeks blog.

 

Monitoring the Great Stairs environment

The Great Staircase was entirely remodeled by Thomas, 1^st Earl of Dorset, between 1605 and 1608. It formed a key stage in the formal procession of the family and their guests from the Great Hall to the state rooms on the first floor.

The wall paintings decorating the main staircase at Knole are rare and very important survivals of Renaissance decoration. Dating from about 1603, they are one of only two complete schemes which survive from this period (the other is at Harrington Hall in Worcestershire) and presage the development of sumptuous painted staircase schemes in the late 17th or early eighteenth century, as seen in the King’s Apartment at Hampton Court Palace.

The paintings were executed in oil on plaster and have been unstable from an early period. Oil paint tends to lift and flake in the English climate, and their location also makes them particularly vulnerable to damage by touching. Flaking eventually leads to loss of the paint, seen in the white spots over the painted balustrade. The following images illustrate some of the damage and earlier remedial conservation repairs that have taken place over the years:

Areas of paint flaking revealing the plaster underneath

Patches of earlier repair, some of which are now failing and the paint is flaking off again.

As a part of our Inspired by Knole conservation project we are currently undertaking some extensive environmental monitoring of the staircase, internally and externally. We have placed temperature and relative humidity sensors on the external wall of the staircase and on the inside wall.

One of the internal sensors, on the north wall. The second is positioned on the east wall

This will allow us to monitor what the temperature and relative humidity levels of the external wall surface and the internal wall paintings. Using time lapse photography we are also recording where direct sunlight falls on the external and internal walls.

The time lapse camera recording direct sunlight on the external wall of the Great Stairs.

 Our conservators who came to install the monitoring equipment also took some thermal images of the walls, another method to record the temperature of the wall surfaces.

Inside thermal imaging shot.

 

We are also monitoring another two wall surfaces to draw comparisons with the Great Stairs. The Spangled Bedroom, with new render and insulation; and the Brown Gallery which has relatively new render but no wall insulation. In these locations we have a temperature and relative humidity on the external surface and in-between the render and internal plaster. By monitoring the effects of new render and a wall with and without insulation, this will help us decide what the best method of protection will be for the Great Stairs wall paintings.

Alex, Emily, Lucy, Melinda, Sarah and Zena

Understanding British Portraits – painting conservation at Knole

Another paper delivered at the Understanding British Portraits seminar last month was by Melanie Caldwell, paintings conservator on the “Past and Future Conservation of Paintings at Knole”.

Melanie delivering her paper in the Great Hall at Knole

“Damp, which is the most insidious of all enemies… steals in while we sleep; damp is silent, imperceptible, ubiquitous. Damp swells the wood, furs the kettle, rusts the iron, rots the stone. So gradual is the process that it is not until… the whole thing drops to pieces in our hands, that we suspect even that the disease is at work.”

Virginia Woolf, “Orlando”, first published in 1928.

Introduction

Over the last 40 years, since National Trust condition records began high humidities at Knole have caused problems for the paintings leading to mould growth, whitened opaque varnish layers and flaking paint. An overview of the conservation records over the last 200 years provides some insight in to changing conservation priorities for the paintings, and approaches to conservation for the future.

The majority of paintings in Knole have had some conservation treatment over the last 400 years although not all of it has been recorded. We can see evidence of previous restorers in discoloured over paint, traces of older darker varnishes, linings and tear mends. It would be extremely unusual for paintings of this age not to have received attention.

Historical Restoration

The earliest recorded restoration at Knole was from the very late 18th and early 19 centuries by Painter/Restorers, who carried out Restoration alongside Painting. Restoring according to Edward Edwards writing in 1808 was “a good resource for the invalids in painting”.1 But on the other hand there was a Status attached to Artists who were capable of understanding and working on Old Masters, perhaps begun by Joshua Reynolds who restored his own paintings and others as a way of studying old master techniques

According to Bridgmans Guide to Knole the Raphael copies and some of the Reynolds paintings, were “cleaned and restored to their original spirit and beauty by that “excellent artist”, Mr John Rising”.2 We don’t know the actual date but the Guide dates from 1817. John Rising was in fact one of Reynold’s painting assistants.3 The presence of Rising working at Knole is certainly interesting, and the possibility exists that Reynolds himself may have been involved in supervising or restoring his own paintings at Knole before his death in 1792.

Another early Painter/Restorer and Dealer was Francis Parsons who between 1793 and 1797 cleaned the large set of historical portraits in the Brown Gallery and ornamented their frames at a cost of 4 guineas for the 3rd Duke of Dorset. He was also working at Knole again in 1796 on other unidentified paintings. All we know of his working methods now are from his advert, May 1784 in the Daily Advertiser that stated that he would “clean and repair Pictures by a Method that restores the Beauty of the Colouring without injuring the most delicate Teints’.4

William Seguier, noteworthy as First Keeper at the National Gallery, Superintendent of the British Institution and Surveyor of the Kings Pictures, also worked on at least six of the paintings at Knole around 1826. He is remembered chiefly for his minimal cleaning at the National Gallery, and the particular type of varnish he used – ironically a mixture of oil and mastic that unfortunately over time becomes very insoluble.5

From the mid 19th century to the mid twentieth century no conservation records have yet been found, although this does not mean that work was not carried out.

By the 1950’s and 1960’s the National Trust were involved with Knole, and the day to day correspondence between Mason the Knole House Steward, and Bobby Gore the National Trust’s Historic Building Secretary, refer to a “local man” who was called in when a picture needed attention.6 He is named variously as Waters, Walters and Walker. In Gore’s opinion Walters was described as having a hand “that is far from light, but he was cheap and he worked on the premises”. W e know nothing of what he did apart from one painting, The Unknown Portrait of Edward Cranfield, which was given a shellac varnish. The use of shellac might imply that Walters was more used to working with furniture than paintings.

Obviously we cannot say exactly what Walters did at Knole. But we can see evidence of a type of typical country house repair work, often carried out by local craftsmen on paintings in situ. Partial cleaning in the paler areas of the sitter’s faces; some more large scale uneven cleaning carried out while the paintings are framed; and possibly even on the wall. Drip marks from, we imagine, large wet swabs that have cut in to the surfaces of varnish and paint, lumps of cottonwool left on the surface of paintings during careless cleaning. Areas of flaking paint and loss that have been reattached and filled in with large clumsy oil retouchings which would have served both purposes, sticking the paint on and filling in colour loss. Nails tacked through the front of paintings to reattach them to stretchers. There are examples of all this at Knole. We can speculate that the whitened areas of varnish that we see on the Knole paintings may be exacerbated by water based cleaning methods– easier to use than solvents on site, but in the case of Knole not ideal as it might encourage mould growth. We can see evidence of this type of crude approach at Knole

By the 1970’s there are records of London based freelance Restorer/Dealers (rather than artists) working on the Knole collection. Keenan, Ellison and Freeman who are all recorded in the National Portrait Gallery’s List of Restorers.

In 1976 Hermione Sandwith carried out the first proper condition Survey of Paintings and since then independent and museum conservators have been bought in regularly to work at Knole carrying out preventative and remedial conservation, and a number of paintings have had full conservation treatment. 3

Condition of paintings

These initial condition reports from the 1970’s do not mention mould growth, but a great deal of flaking paint which was the main priority for conservation work carried out during this decade

Although the house was always known as cold and damp, the first actual outbreak of mould on the paintings was recorded in 1981 in all the rooms apart from the Brown Gallery and the Ballroom. National Trust memos in 1981 describe the moulds’ occurrence as exceptional and blamed the very bad winter and the restriction on ventilation due to building work. Gary Thomson the National Gallery’s Scientific Officer was called in to advise and he confirmed that the “unusual condensation sometimes followed by mould, has been pretty common after last winter.” There followed a major campaign of restoration, much of it carried out under Alec Cobbe and the Hamilton Kerr Institute throughout the 1980’s. Most paintings were treated in situ to remove the mould. It was brushed off, but in some cases led to costly varnish removal, paint consolidation, re-varnishing and lining. Since then mould problems have been noted in 1988, 1991, 1993, 2001 and then continuously really, whenever conservation staff have condition checked the paintings.

Why did mould occur at Knole at this time?

Most of the showrooms at Knole are unheated, and the low temperatures inside the house have exacerbated high humidities providing ideal mould conditions. Very unusually mould is often present on the front of the paintings, not only the reverse. This is probably because the front of the paintings become so cold sometimes that condensation, water droplets, actually form on their surfaces at a microscopic level, which together with household dust that the mould can feed on, provide the right conditions.

Other factors may play a part and more research is needed to establish why the mould first appeared then, if indeed it did. For instance did the showrooms in fact have some heating such as open fires before the National Trust took over Knole in 1946, or after? Are there new moulds that grow at lower relative humidities? Does the humidity from increased visitor numbers play a part, or even Climate Change? What is clear is that mould spores have now penetrated throughout Knole and when environmental conditions deteriorate the spores sprout.

The low light levels essential for the fragile, rare textiles at Knole exacerbate this. Mould growth is restricted by UV light that is found in daylight. At the moment these low light levels have one advantage – hiding the condition of some of the paintings. The building work at Knole will include better lighting. This will mean that the surface problems on the paintings will also be more visible

In a condition survey in 2012 least 80 of the approximately 310 paintings were noted to be affected by mould; and at least 90 paintings were noted to have de-saturated whitened varnish layers. 4

High relative humidities have other consequences for paintings. Panel paintings have warped or split in the fluctuating humidity, canvas paintings can be slack and deformed with areas of raised and flaking paint. Varnish layers are also affected by cold temperatures making them brittle and de-saturated. Damp conditions enable moisture to get into the structure of the varnish giving an opaque, white appearance, sometimes in patches or associated with crack patterns, sometimes as a more overall problem.

The mould itself may be pushing paint off. Glue size layers and glue paste linings provide another food source for mould. The mould appears to be growing under the paint, pushes up through cracks, dislodging paint, causing flaking and loss. Mould spores within the painting structure cannot really be removed and so the only treatment option is preventative – to keep relative humidity below 70%.

Recent conservation work

The fluctuating humidity and temperatures levels generally accelerate the ageing process of paintings and of restoration work. Paintings that have been sympathetically restored as recently as 1998 have redeveloped surface issues. The Diana and Acteon, after Titian in the Billiard Room was restored in 1998 and in certain lights we can see that mould growth and varnish issues are reasserting themselves. Tina Sitwell noted in 1993 “mould and de-saturated uneven varnish layers would be expected to come back within 10 years”. (In general the Trust hopes in situ work will prolong full conservation treatment by 25-75 years.)

There has been an over reliance on making do with in-situ work in the light of the futility of carrying out expensive full conservation treatments that don’t last. Lady Martha by Mytens that hangs in the Leicester Gallery has had repeated in situ work (1972, 1973,1988) but it’s appearance is still unsatisfactory. Delaminating canvas, raised canvas seam with flaking paint, thick discoloured overpaint covering original paint. The surface is patchy with mould or opaque varnish, and it can only now be improved by full conservation treatment. This in turn will only be worth doing once the environmental conditions are stabilised.

What has worked at Knole

Not surprisingly the choice of conservation materials affects the longevity of the restoration. The Titian already mentioned, was relined using traditional paste glue on to linen. On the other hand Lionel Cranfield by Mytens in the Leicester Gallery was lined and restored in 1996 using synthetic non moisture responsive materials (Beva 371 adhesive and polyester sailcloth). The mould growth and cracked opaque varnish noted and treated in 1992, 1993 and then again in 1996 have not yet reappeared, although the varnish is now slightly de-saturated.

Future work

In the future the programme of building work should make Knole leak and draught proof. Work in the Reynolds Room is now complete, conservation heating has been installed using a heated mat placed under the carpet to form a large low level warm area. By increasing the temperature in the room by only a couple of degrees, the relative humidity stays below the mould growth set point of around 70%.

Once this was established the Reynolds Self Portrait came to the studio to trial the type of in-situ conservation that will be possible in the Knole studios in the future. The Reynolds is an extreme example of the typical problems in this room with mould and perished patchy varnish layers. After proper examination of the painting, cleaning tests and analysis to understand the complicated layers of paint and varnish, it was relatively straightforward to remove surface dirt, mould and just one thin top layer of varnish probably applied in situ during the last 50 years. Much of the patchy white surface deterioration was in fact in this top layer. After this, consolidation of raised paint, minor adjustments to the retouching, and re-varnishing, the surface has improved. We are now monitoring this painting to see if the varnish remains saturated and that no mould reappears. This type of treatment is particularly relevant to the Reynolds paintings as they are often very soluble and so full cleaning may not be possible, even if it was desirable.

 

Reynolds, self portrait, on right: after conservation surface cleaning, on left: detail of surface condition before treatment.

 

As the work at Knole progresses and the environmental conditions improve in each room, conservation and restoration programmes can be re-established. On site at Knole conservators will carry out remedial work in a well-equipped studio, including proper technical examination, analysis when necessary, and with equipment to carry out some removal of more recent varnish layers to improve the paintings’ appearance. It is an exciting opportunity for research – even just examining the painting backs and the stretchers labels will provide new information on their history and condition. Full conservation treatment priorities will be have to be decided and a difficult balance must be found between the absolute necessity of work on this important collection, with an awareness of the house’s history and a sensitive approach to how the paintings have been displayed historically.

Melanie talking about conservation of Reynolds portraits on a tour of the show rooms.

References

1 A Laing, article William Seguier and Advide to Picture Collectors, from Studies in the History of Painting Restoration 1998, Archtype publications, Ed. Christine Leback Sitwell, Sarah Staniforth.

2 John Bridgman, An Historical and Topographical Sketch of Knole, 1817, p.56,J Simon, Website of British picture restorers, 1630-1950, http://www.npg.org.uk

3 J Simon, Website of British picture restorers, 1630-1950, http://www.npg.org.uk

4 J Simon, A Guide to picture frames at Knole, Centre for Kentish Studies: Sackville Manuscripts, U269/E426).

5 A Laing, article William Seguier and Advide to Picture Collectors, from Studies in the History of Painting Restoration 1998, Archtype publications, Ed. Christine Leback Sitwell, Sarah Staniforth

6 National Trust corresepondence 1950’s

What to do with wet and mouldy antlers?

The Knole collection does not have many natural history objects, apart from antlers.  Some, like those below, are quite small…

Antlers over the fireplace in the Brown Gallery.

…others are huge!

Irish Elk antlers that hang in the Loggia, found in a peat bog in the 18th Century. They are 10,000 years old!

The antlers from the Brown Gallery had temporarily been in store. Unfortunately where they were stored suffered from water ingress during the wild, wet and windy weather over Christmas.  The storage box they were in had collected a lot of dripping water.

This subsequently led to mould growth on the surface of the antlers.

As none of the antlers in the collection had become wet, or grown mould before, we weren’t sure what the best course of action was. So que an e-mail to the National Trust’s advisor on natural history Simon Moore.

Parts of the antlers were still very damp.

Simon’s advise was to dry any surface water off of them using paper towelling.  Then using a hogs hair brush, apply industrial methylated spirit to remove and neutralise any fungal growth.

Applying the methylated spirit.

After leaving methylated spirit on for about five minutes any excess fluid was removed with paper towelling.

Drying off excess methylated spirit.

Both antlers after methylated spirit treatment.

Then we needed to consider a suitable location to leave the antlers so they could dry out, but slowly.  If rapid drying was to occur this could have resulted in cracks and splits in the antlers. The relative humidity of the space chosen had to be between 50-55%.  So that meant there was only one room we could use, the Great Hall.  This is currently the only room in which we have consistent environmental control and could guarantee that the relative humidity would not get too high and potentially damage the antlers while they were drying out.

The antlers have been in the Brown Gallery since at least 1881, when this photograph was taken.

After two days drying out in the hall we inspected the antlers for any signs of active mould or the effects of drying out.  We’re pleased to say that the mould that had grown has gone with no evidence of new growth.  They have dried out nicely without incurring any damage.  We’ll update the object condition report to record the fact they got wet and grew mould and how we treated them and have them back on display for when the house re-opens on 8th March.

So now you know what to do should your antlers ever get wet and mouldy!

Alex, Emily, Lucy, Melinda, Sarah and Zena

Our favourite objects – part 3

My favourite object is found in the King’s Room. The dark, ebony cabinet can sometimes be overlooked in a room filled with shimmering silver. It is thought the cabinet was made in Paris in around 1650 and has carved decoration on the exterior doors including flowers and scenes representing the story of Jonah and the Whale.

It came to Knole from the palace at Whitehall through Charles, 6^th Earl of Dorset as a ‘perquisite’ from his office of Lord Chamberlain. The cabinet has twelve legs and is relatively unassuming from the front.

However, cabinets of this type followed an established tradition whereby the decoration became more complex and opulent as the cabinet was opened. Inside, it is richly decorated with various inlaid woods, mirrors and tinted ivory.

There are more secrets hidden inside, such as a handwritten note by Vita Sackville-West, written when she was a child. The note was found during routine winter cleaning in 2007, hidden at the very back of the cabinet, inside a secret drawer.

It was previously unknown to Knole staff at the time of its discovery and reads: “Dada, Mama and Vita looked at this secret drawer on 29^th April 1898. Vita.”

Cabinets like this one were hugely popular, particularly in France, from about 1640 to 1660. Owners of such cabinets would have used them to house precious objects and rare curiosities as well as being decorative and luxurious pieces in their own right, demonstrating the wealth and status of their owners. Ebony was a fashionable wood for veneering during this period and was imported into France as trade routes across the globe became more firmly established around the middle of the 17^th Century. The high cost of importing the wood added to their luxury status and they were popular among the nobility.

Skilled, French carpenters who were able to make cabinets of this kind became known as ébénistes, after the wood which they often worked with. The popularity of these cabinets waned from around 1660 until the early 19^th Century when antiquarian tastes became more established. Cabinets were often restored during this period or panels from them were reused elsewhere.

The cabinet is in one of the few showrooms with any environmental control. Despite having suffered some damage over the centuries, it remains in a secure condition as a result of the stable environment in which it is in. Unfortunately, the cabinet has suffered in the past from pest insect infestations, primarily woodworm. It is closely inspected annually during the winter clean, during which time we look for signs of damage, pests or hidden secrets.

Previous woodworm (Common Furniture Beetle) damage to the cabinet.

Lucy

Mould mould everywhere!

Of the 310 paintings at Knole at least 80 have some level of mould on the surface. Although mould is present or suspected in all rooms, the worst appears to be in the Spangled Dressing room, the Billiard room, the Leicester Gallery and the Reynolds Room and is a direct result of the very poor environmental conditions.

Mould on the surface of the painting ‘Heraclitus’ in the Billiard Room

Mould penetrates the varnish and paint layers on paintings causing a white bloom on the surface, flaking paint and degradation of the canvas support. If left untreated this damage can become irreversible.

More mould on a portrait in Lady Betty’s China Closet

In order to plan how we improve the environment in the showrooms in the future and how we can conserve the paintings, we need to better understand this mould growth; why it appears on some paintings and not others and in some rooms and not others; what factors influence its growth; how can we conserve the paintings and ensure the mould doesn’t return.

‘Cimon and Iphigenia’ bt Sir Peter Lely in the Spangled Dressing Room

We have just started working with The Courtauld Institute of Art on a research project to investigate this mould problem. Six second year students are undertaking a full survey of environmental conditions in the showrooms, looking at data from the past and present to see how the current building works will affect the conditions.

Mould spores already growing in The Billiard Room…

…and in the Spangled Dressing Room, spores began to appear within 48 hours.

The Petri dishes will collect mould spores that can then be analysed and identified. Samples have also been taken from the surface of some paintings and again will be analysed and identified. This project will run for 1 year.

Siobhan

Counting down and this and that…

By the time September comes around and the school holidays are over we begin to think about the winter clean and the colder months ahead.  Although we’ll be wearing every item in our wardrobes in a bid not to get hyperthermia as we work, the winter clean is probably all the team’s favourite time of year.  Less monotonous (but important) vacuuming up and down of show room floors but instead every day is spent up close and personal with the collection as we clean and condition check every item before putting them to bed in their dust covers or acid free tissue paper.  We’ve still got one more open week to go, and as well as all the regular open season cleaning here are a few other things that have gone on in recent weeks:

Ian Tyers, dendrochronolist, returned for further investigation of some of the panel paintings from the Brown Gallery. Check out an earlier blog to find out more https://knoleconservationteam.wordpress.com/2012/07/14/dendrochronology-isnt-easy-to-say/

Another leak in Lady Betty’s Bedroom, just as we were preparing to remove the carpet, we had to stop to get the buckets out! The building work hasn’t got to this end of the East front yet. We can’t wait till it does!

Barbara Villiers (by Sir Peter Lely) returned from the Hampton Court Place ‘The Wild, the Beautiful and the Damned’ exhibition at the beginning of October.

The painting has been on display in the Great Hall since it returned from exhibition. This has been for two reasons. 1: to reacclimatise the painting back to the environmental conditions back at Knole. 2: The Spangled Dressing Room where she would normally hang is being used as a temporary store room during the first phase of the external building repairs. It is full of furniture and paintings from other show rooms in the first half and there is not enough space to squeeze Barbara in too!

Furniture in the Museum Room has been covered in Tyvek to protect it from dust and debris before the removal of the render on the exterior wall.

Dust and debris that has found its way in to the Billiard Room, so a good job the Campaign Chair has its dust cover on!

Packing up the contents of Lady Betty’s rooms was hard work, but we had fun too! Lisa (volunteer Conservation Assistant) thinks about an image change!

Lucy, Emily and Helen enjoyed the Attingham Trust’s 60th Anniversary Conference. It was very interesting to hear from a range of speakers as enthused about our country houses as us 3 geeks!

Sarah cleans the pelmet from Lady Betty’s Sitting Room.

Our wonderfully tidy emergency salvage store. We’ve recently relocated and restocked the store room as part of the revision of emergency planning. We had a lot of items delivered and it got in to a bit of a mess while we didn’t have the time to sort through all the equipment. Lucy and Zena (volunteer Conservation Assistant) spent a chilly afternoon sorting it all out.

This year’s winter clean will be filmed on our time lapse camera, so you can follow our work every step of the way!

Emily, Melinda, Sarah and Lucy

Clean, pack, move…

…and four days later two show rooms are cleared of their contents.  It sounds like three easy steps, but nothing is ever that easy at Knole.  Packing away Lady Betty’s Bedroom and Sitting Room for the next stage of the external building work required a lot of planning, overcoming logistics and weather issues and some hard work from staff and volunteers.

For the internal dust protection to be installed it was decided it would be easier to remove all the contents to store, as there is no space elsewhere in the show rooms to store the objects.  Both rooms will remain closed to visitors now until the end of the season.  As they are two of the smallest rooms on the visitor route it would not have been feasible to install the protection and maintain visitor access safely.

Dust screen in the window of Lady Betty’s Sitting Room.

Inside this box is Lady Betty’s bed. It was much simpler to leave it in-situ than dismantling it and finding space to store the parts.

By boxing in the Lady Betty’s bed to protect it in-situ we risk creating a micro climate inside the box and the levels of relative humidity could be increase beyond what the materials of the bed are used to.  Therefore we are monitoring the environment inside the box with a relative humidity and temperature sensor.  The sensor sends regular readings back to our computer so we can track the conditions over a 24 hour period.  Should the levels of relative humidity remain consistently too high we can open hatches in the box to get some air through and allow the additional moisture to dry out.

Environmental monitoring equipment inside Lady Betty’s bed box.

Lady Betty’s bed before being boxed in. The plain wood of the walls is now visible as we have removed the two tapestries.

So what did we have to do pack away all the objects…?

Every object being moved to the store room was cleaned and condition checked.  It is important that we make an accurate assessment and record of the condition of each object before we move it so that we can determine if any damage occurs during the moving process or while the objects are in store.  Of course when handling objects we are always extremely careful, but carrying them out of the house, across two courtyards and up over 40 stairs to the store room does carry some risk of potential minor damage.  However the risk of moving them to store is considered to be a much smaller than leaving them in-stiu during the building work.

One of out volunteers cleans and condition checks one of the chairs from Lady Betty’s Bedroom.

Sarah and volunteer Lisa cover one of the cleaned chairs, after photographing and updating its condition report form.

Every object was also photographed before having their dust covers put on.  At the end of each day we carried the collection up to the temporary store room.

The Conservation Team working very hard. Lucy updates object condition reports on the laptop.

Sarah, Melinda and volunteers Zena and Jo clean 2 of the 30+ paintings from Lady Betty’s Sitting Room and Bedroom.

The smaller and medium sized paintings are carried and stored in crates. The bottom of the crate is padded out with plastazote (a high density inert foam), then each painting is interleaved with plastazote. The paintings are placed in the crate back to back or face to face. Acid free tissue paper and bubble wrap are used to fill voids in the crates and limit movement of the paintings during the journey to the store room.

Paintings on the move!

Happy smiley Conservation Assistants.

Just a few stairs to climb!

After four stools, six chairs, one table and many many paintings we then had two tapestries and a carpet to role!  Here is a time lapse video of the four days work to pack away all the contents: Packing away Lady Betty’s Rooms

A massive thank you to our volunteers Sam, Zena, Lisa and Jo for their help, we couldn’t of done it without you!

Emily, Melinda, Lucy and Sarah