Conserving a Burmese offering vessel 

In April 2023, I began my student placement in the Organic Conservation Studio at the British Museum. One of my first projects involved preparing one of a pair of hsun-oks for display in the upcoming exhibition Burma to Myanmar.  A hsun-ok is a vessel for holding gifts and offerings made by people to Buddhist monks and monasteries. The vessel is intricately crafted from coiled bamboo strips and its decorative surface is a spectacular example of the hmanzi shwe cha style – a Burmese term to describe a technique where gilded relief work is set with coloured glass. When the hsun-ok arrived in the studio for treatment, it was set out in its two main parts, a stand and lid, with an internal offering tray sitting between the two.

It was made in about 1860–90 and was showing evidence of age along with other condition issues. The object's complex shape meant that dust had settled in hard-to-reach places and the aim of this treatment was to restore the object to its former glory by removing as much dust as possible and make sure the object was structurally stable before going on display in the exhibition.

In advance of any cleaning, I wanted to learn more about the object's composition and how this might affect my approach and materials. Thayo paste, a putty made of lacquer and bulking material such as ash, was used to craft the elaborate three-dimensional floral and abstract decoration, into which mirrored sequins, glass beads, and cut-glass stones were pressed. Close examination of the decoration suggested that the surface was subsequently coated with lacquer to adhere the gold leaf. In multiple areas the gold leaf overlaps the glass sequins, implying that the sequins had to be 'excavated' again after gilding. In some areas, this left the sequins slightly recessed. This meant I had to take extra care when moving over the surface to clean the object to avoid catching the gilded surface with any cleaning material.

Often, the first instinct when seeing a dusty object is to assume it needs to be cleaned. Cleaning or removing dust is not always necessary, however, as it can often remove vital historical evidence of the object's use and history. But with this vessel, this was not the case so we decided to remove more recently accumulated dust to allow the object to shine in the exhibition.

I tested various materials and found that three surface-cleaning products commonly used in conservation were effective in removing dust build-up in different areas. Firstly, I used a 'smoke sponge' to remove the heavily embedded dust on the sides of the object. Smoke sponges are made of vulcanised (strengthened) rubber which traps dirt and dust within its bubbled structure when swiped against a surface. This sponge was originally manufactured for the salvage of fire-damaged buildings, and its ability to clean soot from walls gave the sponge its name. For removing the superficial dust which had settled on flat surfaces, make-up sponges worked well. These are soft, absorbent sponges with very fine pores that readily pick up dust and dirt when applied to a surface. Lastly, I used Groomstick, another vulcanised rubber product, which takes the form of a putty that can be moulded onto a skewer to form a small tip. This proved very useful. With its slightly sticky surface, dust particles could be trapped while reaching into the tiny crevices found on the object.

Once the surface had been cleaned, I moved onto the next stage of the treatment: ensuring the structural integrity of the vessel's finial (ornamentation at the top of an object) which was showing signs of instability. The finial depicts the hintha (or hamsa) bird, a semi-divine creature associated with Buddhism and wisdom, which I felt was the crowning jewel of the object. The wings and tail of the bird had been intricately constructed from four separate metal sheets, and lacquered and gilded like the rest of the object.

Upon physical evaluation of the finial, I noticed that the sheets of metal forming the tail were coming apart from the central column on top of the lid, and because these were at risk of detaching completely over time, I decided that they should be treated. I opted to secure the tail back onto its central support with the help of Paraloid B-72, a synthetic conservation-grade resin glue favoured for its versatility, reversibility, and excellent aging properties. I used modelling clamps to keep the sections in place as the resin cured overnight. 

Once the structure had been stabilised, I assessed the lacquered and gilded surface coatings on the metal sheets. There was noticeable cracking on these surfaces, with some fragments coming loose. The reason for this might be the flexible nature of the metal sheets compared to the inflexible lacquer coating: it appears that the sheets had moved repeatedly, placing stress on the rigid lacquer which eventually caused the lacquer to crack and dislodge completely in some areas. I used the same resin, Paraloid B-72, in a much thinner solution to treat this surface-level instability and ran it into the gaps using a hypodermic syringe – an example of an unlikely tool adopted by conservators! Some of the gilded lacquer fragments on one wing had cracked to the point where they needed to be removed, joined together and reattached, as you can see below. 

Once the treatment had concluded, I placed the lid back onto the base to see the object in its full glory and finalise my recommendations for exhibition display and future storage. It was interesting to note that there was no one position where the lid and base sat perfectly flush with each other, however this highlights the handcrafted nature of this object.

This was a successful treatment and having so much time to dedicate to this dazzling object was really special. As a final-year conservation student at University College London, I had never previously worked with something of this scale or prepared an object for a major exhibition. The support of the Organic Conservation Studio team was invaluable and helped me gain an appreciation for the amount of time needed to really care for objects like this. I also had a chance to discuss this object's display context and the story that this was going to tell with the exhibition team. The exchange of knowledge and ideas made this a deeply collaborative project, and I feel privileged to have been a part of this object's story and to have contributed to what will be an incredible and visually stunning exhibition. 

You can see the hsun-ok Maxim conserved along with more than 100 objects that span 1,500 years of Burmese history in our latest exhibition, Burma to Myanmar, which opens 2 November.  You can find the accompanying catalogue in the British Museum Shop.  

Supported by Zemen Paulos and Jack Ryan