I am a masters student of Conservation Practice at Cardiff University, and over the last few months I have been volunteering at Glamorgan Archives, assisting with the conservation of the Plymouth Estate maps. These are a collection of maps and surveys from 1766 covering much of the historic county of Glamorgan. They provide an important record of an area of landscape that went through huge topographical changes during the industrial revolution, and a grant was obtained by the Archives to conserve them.
The first part of the process I was involved in concerned one of the most mould-damaged books. This book had already undergone the washing treatment described below, and now required removal of the old repairs. These were considered inappropriate, too heavy in places and too light in others, and did not deal with all the damaged areas. In places they were also too large and covering information.
The areas of damage were consolidated by brushing with a 2% solution of the consolidant Klucel G in ethanol. Lens tissue was laid on top of this, and more Klucel G solution applied to gently adhere the lens tissue to the top of the page.
The next stage was the removal of the old backing repairs. A page was laid face down on a sheet of Bondina, a non-woven polyester, on a suction table. The extent of the mould damage necessitated the suction table to hold down the areas of damage during the removal of the old repairs. With less damaged paper old repairs could have been floated off in water; however, in this case the severely mould-damaged areas would likely have disintegrated. An alcohol-water mix was applied in small sections to the areas of backing, briefly allowed to soak in, and then the backing was carefully teased apart from the original paper mechanically with metal dentist tools and small spatulas.
Once this was complete, the page was then turned over and the lens tissue removed from the front. A very thin Japanese handmade paper was applied to the damaged and missing areas with wheat starch paste. The properties of this paper meant that the repairs could be taken right up to the edges of the damaged areas without reason to overlap as was the case with the previous repairs, thereby not obscuring any areas of original material.
Next I was involved in the washing of one of the other books which had yet to be treated. The first step in this is to protect the red ink used in the ledgers that accompany each map during the washing step, as tests had confirmed this ink would run. Cyclododecaine is a wax used in conservation treatments to temporarily cover areas of objects as it naturally sublimates over a few days leaving no trace. This was applied to these lines with a special tool that melts the wax and allows it to be neatly and accurately applied (after some practice!).
Once these areas were protected, the maps were wetted with an isopropanol alcohol-water mix and sandwiched between large sheets of Reemay, a spun polyester sheet which would hold them together and stop them tearing under their own weight when being moved between baths.
Two large baths were used: the first was a five-minute water bath, which removed the discolouration caused by the iron-gall ink used in the drawings. You could clearly see the gradual colour-change in the water proving its effect. The original plan was to also treat the papers with calcium phytate at this stage, which actively removes the damaging parts of the iron gall ink itself; however tests found that this was negatively affecting the colour of the copper inks and so this step had to be omitted.
After this, the maps were moved to a bath containing calcium carbonate solution for another five minutes. This solution acts as an alkali buffer, hopefully protecting the pages from any further damage the acidic corrosion products of iron gall ink may cause.
After washing, the Reemay is replaced on both sides of each map with Bondina sheets, taking care to avoid any creases as these will dry into the maps. They were then left on racks to dry.
The final process is sizing. Once the cyclododecaine has fully sublimated, the papers will be wetted out once again and brushed with a solution of 2% gelatine. This encapsulates the damaging components of the iron and copper inks, preventing them from further degrading and causing more damage to the documents.
The plan following treatment is to digitise the documents and then rebind the volumes in their original bindings and store them in bespoke boxes. The much-improved condition and ease of handling of the documents will increase their accessibility immeasurably, allowing them to be used by visitors, researchers and school groups. I am proud of my involvement in the project and look forward to seeing the end results!
Cal James, Cardiff University Conservation Practice Student
You can follow the Glamorgan Archives Blog here: https://glamarchives.gov.uk/news/