Thinking of doing a work placement? My experience with CMAS

on Wednesday, 29 August 2018. Posted in Conservation, History Centre

I can’t believe that the first year of university is over! It goes so fast and with so much information it can be a bit overwhelming, but trust me, all that hard work and studying will pay off. The Conservation of Objects in Museums and Archaeology undergraduate course at Cardiff introduced me to a whole new world of practical science, as well as in-depth theory, of conservation materials and specialised equipment, such as x-ray and air abrasion machines. By the end of the year I felt pretty confident with the concept of conservation but was still nervous on how to actually apply the theory with real, archaeological objects; in a true work environment.  This is where a work placement comes in. My first-year placement was at the Wiltshire and Swindon History centre, as part of the Conservation & Museum Advisory Service (CMAS), a commercial business which deals with issues both in museums and in public collections.

Although it can seem daunting at first, this experience is essential for developing those practical skills and applying the theory with real, archaeological objects, as well as understanding the treatment of different materials and the ethical choices conservators must make; focusing on what’s best for the object and adjusting treatment plans with the client’s wishes accordingly. Keep in mind that work experience is for your benefit, so don’t panic when you have millions of doubts and questions because the people you work with are there to help you (even if you ask questions every 5 mins).

So anyway, onto the actual conservation, hooray!

First things first, you will need to assess the object just by looking at it and writing up a condition report, which simply states any observable issues with the object. The majority of my time was spent working with a Roman ceramic oil lamp in the shape of a foot! Quite a fun object from Chippenham Museum, but as you can see there is a bit of a messy application of adhesive around the centre of the lamp where it has broken in two and was re-joined.  There were also scratches, dust and cobwebs on the inside, layers of red dirt/soil on the surface as well as white flaking corrosion (see figures 1-4).

Before treatment:

Figures 1-4

Ok, so the lamp required a good clean and that adhesive definitely needed to come off. Ultimately, the decision was to completely remove the adhesive and undo the join so that I could re-attach the two pieces with a better, cleaner join.  In order to remove the adhesive, I needed to work out what solvent it was soluble in. For this, I took small samples of the adhesive from the lamp by slicing off some of the softer areas with a scalpel, under a microscope.  I then put the samples into a petri dish and tested them with different solvents (see figures 5 & 6).

Testing solvents on the adhesive:

Figures 5-6

After about 30 minutes, I could see which solvent made the adhesive go soft and rubbery. The process of removing the adhesive required quite a lot of patience as the it didn’t want to budge; a scalpel was used to remove larger chunks of the adhesive and a poultice was placed around the join. A poultice was a way of creating a solvent environment to help loosen the adhesive and separate the two pieces. 
 *Just to give you an idea of the tools used in this process, I’ve taken a couple of photos for reference.

Figure 7 From left to right – pin vice, plastic tweezers, scalpel, wooden stick and cotton wool

Figure 8

In conservation, we usually make or own cotton swabs by using a bamboo stick or cocktail sticks (depending on what you’re working on) instead of regular, pre-made cotton swabs.  Making your own means that when the cotton gets dirty it can be easily replaced and the size of the swab can be varied so you can get into the small nooks and crannies that need a good clean. It also means that we aren’t throwing away millions of cotton swabs and being more environmentally friendly.

After many tries, the poultice wasn’t loosening the adhesive, so I went in with the scalpel and pin vice to try and dig out some adhesive in the join. Another poultice was then left on for a couple of hours. When it was removed I was able to gently pry apart the two pieces (finally!) and clean the new surfaces (see figure 9).

Figure 9

Once the old adhesive had been removed, I gave the oil lamp a good surface clean. It was much dirtier than it looked because I got through a lot of cotton buds. The surface looked much more uniform in colour and less patchy overall.  I also gave it a quick clean with a fast-drying conservation solvent to remove any oil or grease from the surface, which may have interfered with the new adhesive.

The new adhesive was made from scratch, using a mixture of solvents and the adhesive in a solid form.  A lower concentrate solution was used to consolidate the edges of the join; this just helps to stabilise the ceramic and reduce risk of crumbling. A higher concentrated solution was then used to join the pieces back together (see figure 10 & 11). Sand bags were used to prop up the object and allow gravity to pull the pieces together. Some masking tape helped stop any movement on the join.

Figure 10

Figure 11

Once the adhesive had dried, I could start procedures to fill the gaps around the join.  Before starting the infill, I used pigments to get some good colour matches to the ceramic. Generally, the infill isn’t an exact match so that it’s easier for conservators to see the treatment and remove it if required. Figure 12 shows some of the colours I tested before application; the clear plastic allows for easy comparison to the object.

Figure 12

Figure 13

It was then time to use the infill on the gap in the oil lamp (see figure 13). Once the fill was applied, it was left to dry.  For my first infill, I wasn’t too disappointed with it but at this point it looked a little messy.  The last step was to trim down the fill and give it a more even surface, so it didn’t cover up the surface of the object too much (see figures 14-18). 

After treatment:

Figures 14-18

Looking at the before and after photo, it’s amazing how different it looks. Overall, I am pleased with the final outcome, especially the colour-matching. I cannot believe how much I have learnt on my first work experience. It has given me so much confidence when working with real objects and making judgments on treatment.  I want to say thank you to the whole conservation team for being so welcoming and accommodating and I wish you well for the future. I can’t wait to get back to university and put my new skills to good use.

Eleanor Moxon, Work Placement Student 2018


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