Conservation at the Museum of Anthropology, Vancouver

Megan Narvey

The conservation program at UCL consists of two Master’s degrees over the course of three years. Two summers of those three years are consumed, more or less, with the writing of dissertations. The middle summer, however, is free. I’m Canadian, and although I’m very happy with my decision to study conservation abroad, I hope to work in Canada when I’m finished. Therefore, I used my free summer to build contacts in Canada by applying for an internship at one of my favourite Canadian museums.

The Museum of Anthropology (MOA) at the University of British Columbia in Vancouver, Canada, has an impressive collection of objects from all around the world, and is most well known for its collection of objects from First Nations groups of the Pacific Northwest. The museum is also known for having a very inclusive policy of working with the communities it represents.

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Haida house totem pole in the Great Hall, from c. 1870. These poles were originally from one pole, which stood outside the front wall of a house called ‘Plenty of Tliman Hides in This House’, a structure belonging to the family of the clan of ‘Those Born at Gadasgo Creek’, of the Raven moiety. Please read more about them on MOA’s online catalogue, here.

I had visited the museum before and was impressed with the collection, the quality of the facilities (there was a major renovation in 2010), and was intrigued by its use of a glass door separating the conservation lab from the galleries. It didn’t hurt that this is the view outside.

The view from the staff lunch area is not too shabby.

The view from the staff lunch area is not too shabby.

At MOA, I worked under the guidance of the conservators Heidi Swierenga and Mauray Toutloff. I completed complex treatments, worked with volunteers, and learned about and assisted with earthquake-proofing of the storage areas (this is not a problem you come across in London!). The most interesting treatment I worked on was of a Kwakwaka’wakw wooden figure.

Before treatment

The figure would have been displayed publicly to honour the greatness of a chief, and depicts a chief being carried on the shoulders of a slave. You can read more about the context of the object here. The figures are painted with red and black paint, and the wood – likely cedar –  has been stained or varnished. The figure needed conservation as, during handling, the thumb of the chief had fallen off due to a failed previous conservation treatment. At the same time, a curator had come across a historic image of the figure where the outstretched arm of the chief was held in a different position. The historic position was more in keeping with the original context of the object, so we were asked if we could return it to this previous position.

Detail of where the thumb had broken

Detail of where the thumb had broken

The first step of the treatment was to determine how the outstretched arm was connected to the body, and how to remove it without causing any damage. There appeared to be a lot of pieces of wood nailed together around the joint, as well as a bright, new wooden wedge and two different kinds of adhesive.

Detail of the arm joint

Detail of the arm joint

After plenty of examination, it was clear that the arm itself was not nailed in place, but only adhered. The adhesive was found to be soluble in ethanol, so it was softened with the solvent and the arm easily pulled out of the socket.

Stage one of the treatment accomplished!

Stage one of the treatment accomplished!

The next stage of treatment was to remove the tenon, of the open mortise and tenon joint, and reattach it at an angle that would put the arm in its historic position. The tenon was attached to the arm with an overly strong adhesive that was causing the wood on the arm to fracture, as well as with six nails. I removed the adhesive with solvent and had to pry the tenon away from the arm using wooden wedges and hammer. Then I removed the nails from the tenon by hammering them out backwards, with a piece of wood to cushion the blows so as to preserve the nails.

The slow process of driving wooden wedges between the arm and the tenon to separate them without causing further damage.

The slow process of driving wooden wedges between the arm and the tenon to separate them without causing further damage.

Both the arm and the tenon were pockmarked with holes from nails hammered in and removed over time. In order to lower my impact on the object, I chose to reuse two of these holes to attach the tenon to the arm in the new position, and used screws instead of nails, which are easier to remove. Finally, I removed the visually obtrusive wooden wedge and replaced it with a piece of 8-ply black acid-free matboard. No adhesive was needed to secure the arm in place.

The arm joint after treatment

The arm joint after treatment

The last step of treatment was reattaching the thumb. Upon examination, four different eras of previous conservation were detected (all prior to the object’s acquisition by the museum in 1973, and the establishment of the conservation labs at MOA). There were wooden wedges, nails, what appeared to be a type of animal glue, and then what appeared to be a more modern synthetic glue. All of these treatments had failed because the thumb lacked good contact with the body. Therefore, I decided to use a combination of fill and adhesive to reattach the thumb to the body, with a modern, easily reversible conservation adhesive.

The thumb, reattached more securely to the figure.

The thumb, reattached more securely to the figure.

After the treatment, the object was returned to its location on display in the Great Hall of the museum, with what I see as a much grander and more imposing appearance.

The object after treatment.

The object after treatment.

My internship experience at the Museum of Anthropology was highly educational and equally fun. To learn more about conservation at MOA or their conservation internship program, please find more information at http://moa.ubc.ca/conservation/.

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Mobilised Salts and Chedworth Roman Villa

Emma Prideaux

Anna has previously talked us through archaeological sites and how conservators assess them, using Billingsgate Archaeological site as an example. But what next? How do you solve a problem like sites next to a marina? Or with a water table that is jusssst a little too high? UCL’s work at Chedworth Roman Villa is a nice example of seasonal conservation work that tackles two problems caused by water: salt damage and microbiological growth.

The Villa

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The Villa Layout

Built in the 4th Century BC, Chedworth Roman Villa is one of the largest Roman Villas discovered in Britain. The significant remains of three wings (or ranges) of the building survive above ground, the best preserved of which contain the dining rooms and the bathhouses. Originally discovered and excavated in the Victorian Period, the villa is now managed by the National Trust. It is famous, amongst other things, for having the only depiction of a British Native in mosaic form.

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The mosaic shows a Roman-Era Briton. He symbolises winter, proving that the British obsession with the weather is really, really old. [http://quibono.weebly.com/]

While the site is stable and well cared for, the site is subject to problems associated with water movement. A relatively high water-table and run-off from the surrounding hills is partially combated by a modern French drain. The water that weasels its way through this defence has a habit of soaking into the foundations. This then allows water to spread to the other surfaces of the building, such as the mosaics. If this water dries, it leaves behind salts on these surfaces. If it doesn’t, it allows microbiological growth, namely algae, lichen, and cyanobacteria (think black sludge) to grow. This can damage and obscure the surfaces. UCL conservation students perform seasonal conservation work, removing salt and algae blooms to help National Trust staff maintain the site.

Cleaning

Sometimes, the cleaning of archaeological sites can involve delicate, painstaking work using specialised tools. Sometimes, as when removing efforvesence (salt blooms) from the surfaces of Chedworth Roman Villa, you do not.

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It’s too late for regret, Rob. We arrived in a communal van and there’s no public transport for you to escape in. You’re going to have to clean it.

It’s a simple process. Sponges are soaked in de-ionised water, which is then gently pressed against the surface of salt-encrusted tesserae. This dissolves the salt, and allows it to be lifted, wicking the encrustation away to reveal the surfaces underneath. By wearing thick socks, and laying down padded walkboards, we can move safely around the site.

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The cleaned tesserae!

Biological growth is slightly trickier. A fast way of killing and removing microbiological growth is through steam cleaning. These tools kill and remove the algae by applying high-heat steam to the organisms, where surfaces are stable enough to use it. You can see the progress and, as we’re essentially ‘boiling’ the algae off, you can also smell the over-cooked cabbage aroma of progress.

However, some areas (such as the mosaics) are too unstable to use steam cleaning. If attempted, we risk dislodging the tesserae en-mass, and beginning the world’s most stressful jigsaw puzzle. Therefore, microbiological growth is removed slowly, using these very special conservation tools:

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Pictured: “Specialized tools”.

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Conservation may be a dorky profession, but we’re always prepared for a barbeque.

But using tiny tools on huge mosaics is time consuming – even by conservation standards, which is saying something. Therefore, in this site we’re borrowing a trick that aquarium-owners use to keep their fish tank clean.

No. Not like this. Chedworth isn't that damp.

No. Not like this. Chedworth isn’t that damp.

Many fish tanks use UV light to kill algae. By exposing the microbiological growth in Chedworth Roman Villa to specific UV light for four days, we can kill it. As we are able to completely killing the microbiological growth, this process will also slow down the rate that biological growth will colonise in this area. An added advantage is that it also vaporises the remains, leaving the mosaic surfaces largely clear of debris. Any residual remains can be cleaned off using toothbrushes and bamboo sticks much, much faster.

Like painting the Forth Bridge, in moving the UV light source from section to section, it takes some time for the whole surface of the mosaic floors to be treated. This means that the UV eradication takes place when Chedworth is open to visitors.   To protect visitors from the UV light, the equipment is contained inside a light proof box , which make it perfectly safe for people to be in the same room.

Having carried out these cleaning techniques, our field trip to Chedworth has left the site cleaner, more stable, more accessible, and more visually appealing. Although it is not possible to totally prevent microbiological growth and salt blooms on the site, these techniques can be used to mitigate the damage that might otherwise result, if left untreated.

Hinemihi Maintenance Day

Vanessa Applebaum

For the past 12 years, UCL conservation students have travelled to Clandon Park to assist the National Trust with the care of Hinemihi, a 19th-century whare nui (Maori meeting house) originally from New Zealand. The Hinemihi kaitiakitanga (Hinemihi Maintenance Day), has become an annual tradition at Clandon Park,and is an event that allows us to gain experience with both preserving heritage buildings, as well as with public engagement in conservation.

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Hinemihi survived the recent devastating fire at Clandon Park and remained unharmed. Whilst the site is currently closed for public access, we were allowed a rare opportunity to work on site,  to carry out a  small scale maintenance project.  This was arranged during the first week of July and five of us were able to take part. Rev. Regan O’Callaghan attended and conducted a karakia in order to clear the way for our work to take place.  The mission this year, presented to us by Dean Sully the MSc programme coordinator,  was to clean and document the condition of Hinemihi’s historic carvings. The removal of microbiological growth (algae and lichen) is of benefit to both Hinemihi’s appearance, as well as her structural integrity.

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Our tactic for lichen removal centred first on wetting the microbiological growth, and then on the use of a combination of dental tools, scalpels, and files to clean the wood. When wetting the wood, we used a 1:1 solution of deionised water and industrial methylated spirit (IMS). This helped loosen the growth  and allowed for careful scraping, without damaging the delicate painted surface.

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Though a variety of instruments were used, my personal preference was a metal file— it provided an edge to remove the lichens, but was not as sharp as a blade, and therefore I avoided cutting into or damaging the wood. The results were very satisfying, as one could note an immediate change to the surface once it had been attended to.

One of our favourite parts of the day was teaching these cleaning methods to National Trust staff and volunteers who work at Clandon Park. Though we wish we could help with the preservation of Hinemihi more often, time and distance preclude this from happening. It is therefore very important to help train others how to carry out  conservation cleaning, so that they may continue Hinemihi’s maintenance in the future.

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We had a great time working on Hinemihi’s care at Clandon Park. For a group of (in-training) object conservators , who often focus on smaller-scale treatments, it was wonderful to expand our breadth of knowledge to include a large-scale heritage site. I can’t wait until next year!

For more information about Clandon Park and  Hinemihi, please  go to (http://www.nationaltrust.org.uk/clandon-park/)

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Olduvai Gorge Conservation Project

Anna Funke

This is a slightly different blog post from what we usually talk about. It is supposed to introduce you to a fascinating project that Abby, Jan and I (all MSc Conservation students who you have heard from in the past in previous blog posts) will be involved with this summer. Although our degree has archaeology in the title, you may have noticed that these posts very rarely talk about the adventurous excavations of lost civilisations in foreign lands.

Well that is about to change! The three of us, also known as the GTCT (Greatest Tanzania Conservation Team) will be going to Olduvai Gorge in – you guessed it – Tanzania this summer! We will be in pursuit of some hard-fast evidence about the lives of early man and woman. This famous site is right at the heart of the theory that humanity’s origins are to be found in East Africa.

Olduvai gorge map

The archaeological research at Olduvai focuses on the transition between the Oldowan and the Acheulean. Both these groups are steps in the line of the human biological as well as technical evolution. The archaeologists on site will therefore be looking both for human remains that can give some insight into the biological stages of our development, as well as for ancient stone tools that can shed some light on our early technical developments. The finds from Olduvai Gorge go back as far as 1.7 million years!

Our contribution to these grand questions will be to try to stabilise these fragile finds so that they can safely be studied. We will also try our hands at excavation by helping out with the lifting of particularly fragile finds.

A Tanzanian student in the Laetoli Lab working on a horn core. Photo courtesy of OGAP.

A Tanzanian student in the Laetoli Lab working on a horn core during last year’s excavation. Hopefully, this will be us soon! Photo courtesy of OGAP.

We are now in the final weeks of preparations before the departure of GTCT in early July! We are getting our vaccinations and gathering our tents, travel showers, and tool kits. We can’t wait to jump in and we hope you will stay tuned for updates during the excavation! If you would like us to send you a postcard, we will happily do so in return for a small contribution to our travel fund. We are so close to going but we still need to raise the last of our balance to make this trip a success! You can help by contributing here or by spreading the word about our project. Thank you for any help you can give!

Find out more about the conservation at Olduvai Gorge here.

A Heavenly Transformation – The Treatment Continues…

Jan Cutajar

Check out the previous posts in the series here, here, and here!

Our last blog post on the treatment of the Norfolk Museums Services angels dealt with some very satisfying flake relaying on Angel A. In this new episode, we shall delve into the treatment of Angel B (shown below in case your memory needs jogging), which had suffered a more severe case of surface delamination than its counterpart. Indeed, the delamination had reached such a severe state that even slights movements of the angel within its packaging resulted in notable loss of gilding!

Angel B, more affectionately known as Gabrielle. Courtesy of Norfolk Museums Service, T1878333.

Angel B, more affectionately known as Gabrielle. Courtesy of Norfolk Museums Service, T1878333.

For this reason, an intensive rescue operation took place earlier this year over three, wintery January days, with the aim of stabilizing the angel so that it may be removed from its packaging and be treated in a similar manner as Angel A. An enthusiastic team comprising of the author, Letty Steer and Dae-Young Yoo was put together and led by a motivating Claire D’Izarny-Gargas.

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The team members hard at work – above, from left to right, Dae-Young Yoo, Letty Steer & Claire D’Izarny-Gargas; below, from left to right, Jan Cutajar, Dae-Young & Letty.

The team members hard at work – above, from left to right, Dae-Young Yoo, Letty Steer & Claire D’Izarny-Gargas; below, from left to right, Jan Cutajar, Dae-Young & Letty.

Given the condition of the angel, it was slightly (if not very!) daunting to actually even consider touching the angel. The first step, therefore, was to develop a method of stabilising very loose flakes. After several initial trials, it was found that the best method, given the time frame we had to work in, was to apply a Japanese tissue paper facing (adhered directly with a 2% w/v solution of Klucel G in isopropanol, a hydroxypropyl cellulose adhesive commonly used with organic materials), which was then heat-activated using the heated spatula. This step allowed the gilding flakes to be slightly re-shaped in the process before relaying. You can see these facings in the pictures above – here are some more detailed shots of the procedure.

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Applying the Japanese tissue facing using 2% w/v Klucel G – where possible, the areas of flaking were cleaned first, as can be seen. Sometimes though, this was not possible and facing was applied directly to severely flaking sections.

Applying the Japanese tissue facing using 2% w/v Klucel G – where possible, the areas of flaking were cleaned first, as can be seen. Sometimes though, this was not possible and facing was applied directly to severely flaking sections.

The same procedure used to relay flakes on Angel A was then used, applying solutions and heating through the paper facing, which was possible due its fibre-thin nature. Once the gelatin (5% w/v in deionised water) had set hard after 5–10 minutes from heat-activation, the facing was removed by first moistening it with lukewarm deionised water and then peeling it off at a 180o angle with a pair of pointed tweezers. Any clean-up of excess gelatin or paper threads could then take place with warm water swabs.

Here’s an example of the complete treatment procedure: (1) flakes before treatment; (2) facing applied; (3) application of 50% IMS and gelatin, followed by heat activation; (4) after setting, the facing is removed with a warm, wet swab; (5) tweezers are used to pull the facing gently off; (6) the area after treatment, success!

Here’s an example of the complete treatment procedure: (1) flakes before treatment; (2) facing applied; (3) application of 50% IMS and gelatin, followed by heat activation; (4) after setting, the facing is removed with a warm, wet swab; (5) tweezers are used to pull the facing gently off; (6) the area after treatment, success!

Once we were confident that this method worked, the angel in its packaging was set on the operating table and the areas identified as most fragile were faced and treated. There definitely was a ‘surgical theatre feel’ to all this, with two conservators each working on each side of the box, passing around spatulae, brushes and adhesive solutions. Everyone fell promptly into their roles and the rhythm of work got going.

Here, Claire and Dae-Young are stabilising the angel, before its removal from its temporary packaging.

Here, Claire and Dae-Young are stabilising the angel, before its removal from its temporary packaging.

The “operating table” so to speak, with different parts of the treatment taking place at the same time.

The “operating table” so to speak, with different parts of the treatment taking place at the same time.

Letty and Young heat activating the Klucel G and gelatin using heated spatulae.

Letty and Young heat activating the Klucel G and gelatin using heated spatulae.

After the first day, the angel was lifted out of its box successfully without any severe loss of gilding. This allowed us to access more surface area on the angel and so the work intensified during the next two consecutive days, as you have seen already in some of the photos. Facings were applied, flakes were relayed and facings taken off. The most challenging areas were the face, wings, chest and feet on the angel due to the undulating surfaces and level of decorative carving. At times, some flakes were broken or damaged during treatment which was heart-wrenching, however, the solution to this was very straightforward: document it and then repair it.

Some stunning work achieved by Claire on the face of the angel.

Some stunning work achieved by Claire on the face of the angel.

Similar successes on the left wing – clearing the facing was particularly tricky here, as it tended to catch on the decorative carvings, lots of care and caution were thus necessary to achieve these results!

Similar successes on the left wing – clearing the facing was particularly tricky here, as it tended to catch on the decorative carvings, lots of care and caution were thus necessary to achieve these results!

At the expiry of the available time, the angel was miraculously looking in much better shape than before, and in turn was also much more stable! Indeed, the success of the treatment allowed us to move the angle from a lying, horizontal position to a standing, vertical one. Advantageously, this then permitted an improved packaging solution to be implemented whilst more work was carried out at a later stage.

The angel after three days solid work – and finally standing whole!

The angel after three days solid work – and finally standing whole!

Yes, despite the advances made at this stage, the treatment was not yet over and further relaying of gilding and paint was necessary. This was completed in part during another similar session in February. In fact, should you wish to know about this session, we will be more than happy to answer your questions in person at this World Archaeology Day Festival at the UCL Institute of Archaeology, come Saturday the 13th June! There’s an even more exciting part though! We shall be working on the angels this Saturday and you will have the opportunity to see how this work is done in real-time. So don’t miss out on this fantastic opportunity to set your eyes on these angelic beauties, we look forward to seeing you!

WE LOOK FORWARD TO SEEING YOU THIS SATURDAY!

WE LOOK FORWARD TO SEEING YOU THIS SATURDAY!

N.B. All photos by Claire D’Izarny-Gargas & Jan Dariusz Cutajar. Permission to post courtesy of the Norfolk Museums Service.

Material Spotlight: Agar Gel

Robert Price

I’m just going to come out and say it – gels are pretty amazing.

Jurassic Park (1993)

Jurassic Park (1993)

No, not this kind…

I mean, sure, Jell-O or Jelly is pretty great too, but I’m talking about the gels used in conservation and my new favorite gel – Agar.

If you’ve done some lab work you’ve probably come across Laponite RD (a synthetic clay), Carbopol (a carbomer resin), or Cellulose Ethers like Methyl Cellulose or Sodium Carboxymethyl Cellulose being converted to gels for cleaning techniques involving water, solvents, or other cleaning agents.

Gels are useful because they minimize the total amount of solvent or water needed for a treatment by slowing the rate of evaporation and maintaining good contact with the surfaces targeted for cleaning – this is good for you, the environment and the object. In some circumstances gels can also have a poulticing effect and are capable of absorbing a portion of the materials they solubilize or soften.

Aside from potential chemical interactions, a big consideration with gels is how easily you can remove them once they have worked their magic – a process known as ‘clearance’. With some gels this might be particularly problematic, especially when used on very rough or porous surfaces. Not all gels are the same though and you need to do some research.

But here’s where my new favorite material comes in – enter, Agar gel.

If you look into the literature you might be surprised to see the wide range of materials it has been used to clean, including: wax sculptures, marble, gypsum plaster, ceramics, wood, and textiles. Anecdotal reports from our peers currently undertaking work placements have also noted its growing use within museums, especially for surface cleaning on limestone.

The beauty of the gel is that it’s capable of slowly releasing water in very small amounts, which means that it can be used to remove or soften water-soluble materials without overly saturating a water sensitive surface. Unlike other commonly used gels, the rigid gel formed by Agar is extremely easy to remove in a single piece and leaves no visible residues behind. This minimizes the amount of mechanical action needed to clear the gel. You should be aware, however, that at least one study has identified trace amounts of polysaccharides within cleaned materials analyzed with GC-MS.

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Comparative clearance tests with commonly used gel concentrations on Melinex

Personally, I have found it to be a promising material for softening and removing proteinaceous glues in situations where excessive amounts of water or heat would be problematic for the object being treated – as is the case for bone and wood.

It’s definitely worth experimenting with, even if you don’t currently have a use for it. While purified agarose can be purchased online, food grade Agar is much cheaper and can be purchased from higher end grocery stores. Even some high profile cleaning projects have gone with this cheaper alternative. I’ve been using Clearspring® Agar Flakes.

Try making a 2% w/v gel by adding 2g of agar flakes to 100ml of boiling water and a allowing the solution to cool within a flat container. The resulting sheet can be cut into whatever shapes you need and will keep in the fridge for a week or more depending on the cleanliness of your equipment and how often you open the container.

A square of Agar gel, roughly 3mm thick.

A square of Agar gel, roughly 3mm thick.

Unfortunately, these tidy little sheets only work well on flat surfaces. As an alternative, the semi-cooled solution can also be placed in a plastic syringe and extruded just before gelation occurs, allowing the gel to better conform to complex surfaces. This takes some practice and familiarity with the material but can be very effective.

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Direct application of the gel near its ‘sol-gel’ transition temperature.

Finally, you can also experiment with forming the gel around other materials as I did with natural fiber strings. The string can be repeatedly dipped in and out of the warm solution until a thick coating is formed around the fibers. Strings with looser twists and greater surface area work best. This gives the gel a support structure and made handling and removal even easier. Possible applications could be for disassembling narrow joins or lying over curvilinear shapes.

Non-dyed, natural fiber strings used as ‘scaffolding’ for the gel

Non-dyed, natural fiber strings used as ‘scaffolding’ for the gel

Hopefully this has been helpful and got you excited about exploring Agar gel further. It might be a good alternative to consider the next time you have to remove proteinaceous glue from a fragile or water sensitive surface.

 

 

Breathing new life into a solvent dispenser

Dae-Young Yoo

In our lab, we frequently hear “does anyone have extra acetone? IMS? White spirit?” Here, the solvents do not mean just solvents, it actually means a solvent dispenser filled with a specific solvent. Why is this such a frequent problem? Let’s find out the reason and sort it out!

Solvent dispensers have been used in conservation labs for some time. These are pump action bottles that allow the controlled use of solvents during lab work. There are many advantages to using these dispensers. Firstly, it makes the controlled application of solvent to cotton wool swabs or brushes much easier, without contaminating the rest of the solvent . The pump on the dispenser transfers a small amount of liquid to the cup at the top. Therefore, there is no need to worry about an excess of solvents or accidental spillage. There are health and safety advantages to using solvents in this way, as it reduces the evaporation rate of solvents, and reduces potential exposure to solvent fumes. Lastly, it is made of plastic which makes the dispenser shatterproof. Even if you drop the dispenser, it remain as it is without gushing solvents out of it.

A solvent dispenser can control the amount of solvent. It makes it easier to apply cotton wool or brush (photo courtesy of Dae Young Yoo)

These solvent dispensers are very useful for conservation practice and routinely used in the UCL Conservation lab. So when they go wrong it usually results in a frustrated cry for help. One major drawback of the solvent dispenser, is the durability of intake tube inside the dispenser bottle. I am not sure if this problem applies to all dispensers in the world. However, most dispensers I have used fail to function because of a problem with the tube, rather than other parts of the dispenser. Most of the broken dispensers in my lab have the same problem. So I figured out why so many classmates end up suffering while pushing the dispenser pump to no effect, and then ending up ’borrowing’ other classmates dispensers. It is really annoying that something does not work properly when necessary.

In this post, I will let you know how to fix it, with materials that are easily available in your lab or workplace. It is super easy and only takes three minutes to fix . I hope this post helps not only my classmates, but also conservators fix broken dispensers by themselves, and therefore remove one element of conservation lab stressing out.

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A crack on the tube reduces air pressure in the tube when the pump at the top is pressed. The principle of pump is the air pressure difference between inside and outside of a tube. Because of the crack, the air pressure between inside and outside of tube is the same, which makes it difficult to suck up solvent in a dispenser (photo courtesy of Dae-Young Yoo)

How to fix it

Everything you need:

– A disposable pipette made of low-density polyethylene (LDPE, which has resistance to acetone, ethanol, white spirit and IMS)

(Note: You should check what your disposable pipette is made of and what types of solvents will be used because some plastic pipette are easily dissolved in some solvents)

– A hot air blower, or a lighter in extreme situations where a hot air blower is not available

– scissors

  1. Heating a pipette

Heating a pipette with a hot air blower.  (photo courtesy of Emily Williams)

Ensuring you have first carried out a risk assessment, and have access to suitable Personal Protective Equipment and fume extraction, heat a disposable pipette with a hot air gun until the colour of pipette becomes transparent. Turn the pipette to ensure that the area is evenly heated. Do not heat just one spot, otherwise the pipette will be burn. In addition, before heating it, you have to consider the height of a dispenser and decide the location of the pipette for heating.

  1. Pulling a pipette
When the heat is applied, the pipette get transparent and soft (photo courtesy of Emily Williams)

Pulling a pipette while it is warm. When the heat is applied, the pipette gets transparent and soft (photo courtesy of Emily Williams)

The pipette is made of polyethylene, which is a thermoplastic polymer. The thermoplastic can be soft when heated and hard when cooled. We will take advantage of the properties of thermoplastic.

Pull the pipette from both sides considering the diameter of the solvent intake. You have to adjust the length of the pipette before it is cooled otherwise it will get hard in a short time so you cannot transform the pipette.

  1. Cutting a pipette with scissors
Separated pipette (photo courtesy of Dae-Young Yoo)

Separated pipette (photo courtesy of Dae-Young Yoo)

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Separated pipette (photo courtesy of Dae-Young Yoo)

  1. Replacing the broken tube with a new one
The pump with a new intake tube (photo courtesy of Dae-Young Yoo)

The pump with a new intake tube (photo courtesy of Dae-Young Yoo)

Replacing the tube is easier when the tube is warm. Otherwise the tube will get hard and could be difficult to fit it into the intake of the pump.

  1. Installing the new pump

(photo courtesy of Dae-Young Yoo)

Solvent dispensers with newly made tubes are working well in our lab. From now on, if you find a solvent dispenser broken, do not throw it away, and pinch another from your lab mates. Check the intake tube inside. If it is broken, just spend three minutes to fix it. Just three minutes will make the dispenser semi-permanent and save money (the price of solvent dispenser is usually over 10 pounds!!).

 

Let the Treatment Begin!

Abigail Duckor

Following the research conducted by Claire d’Izarny-Gargas, further examination led to the formation of treatment plans for Angel A and Angel B. As discussed earlier, Angel A was in decidedly better condition, so it was tackled first.

Claire starting the treatment on Angel A

Claire starting the treatment on Angel A, courtesy of Norfolk Museums Service, T1878333.

On the front and the back of the angel were two different types of surfaces. The front was a gilded layer, which was flaking and delaminating. The back featured a painted layer, also undergoing flaking, but not as extensively. The front and the back of Angel A therefore underwent different treatments. This blog post discusses the relaying of the flaking gilded surface. For the front of the angel the main goals were to clean the surface (which was very, very dirty!) and to relay the remaining flakes. An initial gentle clean was done with a cotton wool swab and a solution of 50:50 IMS (industrial methylated spirit) and deionised water. This method was selected after some cleaning tests were carried out in an inconspicuous area.

Cleaning tests on Angel A.

Cleaning tests on Angel A. Courtesy of Norfolk Museums Service, T1878333.

The flakes were then relayed by first saturating the area with the 50:50 IMS/ deionised water solution. Then, using a small brush, a drop of warmed gelatin solution (5% w/v in deionised water) was placed under the flake. Saturating the area first reduced the surface tension and allowed the gelatin to penetrate under the flake.

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The gelatin was dissolved in warm deionised water. It was kept at 60°C in a water bath. Photograph by A. Duckor

After the gelatin cooled a bit (a few minutes), heat was applied to the area with a heated spatula. A piece of silicone-release paper was used between the  spatula and the angel, to prevent damage to the surface from the tackiness of the gelatin. Pressure was gently applied to the flake with the heated spatula, in a ‘rubbing’ motion. The gradual heating softened the gilding and allowed it to be re-shaped onto the surface of the angel. The heat ‘activated’ the gelatin and adhered the flake onto the substrate.

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The heat spatula and brush used in the flake relaying. Photograph by A. Duckor

This method was very successful in relaying the flakes with little breakage. Following re-laying, further cleaning could be done without risking additional damage to the surface.

The left hand of Angel A before and after the flake relaying. Courtesy of Norfolk Museums Service, T1878333.

The bulk of this treatment took place during the summer months of 2014 and allowed for the involvement of both MSc and MA conservation students – a great opportunity to work together and learn from one another!

Erin Murphy using the heat spatula to gently press down a flake and seal it with the gelatin.

Erin Murphy using the heat spatula to gently press down a flake and seal it with the gelatin. Courtesy of Norfolk Museums Service, T1878333.

Rachel Altpeter and Romina Quijano Quinones working together.

Rachel Altpeter and Romina Quijano Quinones working together. Courtesy of Norfolk Museums Service, T1878333.

Yuqi Chock applying gelatin to flaking areas of gilding.

Yuqi Chock applying gelatin to flaking areas of gilding. Courtesy of Norfolk Museums Service, T1878333.

Photographs by A.Duckor and Claire D’Izarny-Gargas.