When we think of carrying out conservation work on delicate objects we all imagine such processes taking part in pristine white labs with machines that look like they came straight from the set of Star Trek. Here at the SWMM, and for most other Museums, we do not have huge labs in which to carry out conservation work and we certainly don't have Star Trek machines. Instead we have to create solutions to problems with items that we have available, all whilst not sacrificing the safety of the object.
Recently the Museum was lucky enough to have received a anemometer, a device used to measure airflow underground. Unfortunately the anemometer itself was stuck in its leather storage pouch. The item had been kept in the previous owners garage and the leather had shrunk to trap the object inside. It was really firmly wedged in with no way to remove it without severely damaging its leather container.
Because it was trapped inside we were unable to ascertain what condition the anemometer was in. Jodie, a conservation student who helps out here at SWMM, and myself examined the leather and decided that the reason that it had shrunk was because it had dried out. Therefore we decided that we would seek to add moisture back to to the leather. This was not a decision we took lightly as when anybody working with collections talks about adding water to an object alarm bells start to ring. It is not as simple as simply dropping the item in a bucket of water and coming back ten minutes later or even simply spraying it with a fine mist of water. Both of these methods could cause damage to the object by causing a drastic change too quickly, leading to the leather cracking when it had dried out. Also when adding water to leather you also risk creating mold on the object. This item was previously stored in a garage, where mold spores are likely, and added water and leather for the mold to eat would have created the perfect cocktail for mold growth.
So what did we do?
Well we got a bit Blue Peter !
We decided that we would need to up the humidity of the environment surrounding the object. Humidity relates to the amount of water vapour in the air. When storing collections it is important you monitor an area's 'relative humidity', which is the amount of water vapour in the air expressed as a percentage of the amount needed for saturation at the same temperature (all very complicated!), in order to protect your items. If relative humidity is too high then you risk mold growth or other risks to your collection.
So how did we create an environment in which we could monitor humidity? Well with a plastic box, plastic sheeting and a cake rack of course!
We inserted a small amount of water into the box, laid a cake rack down (never used of course!) and then put the object on top of that. We then sealed the the top of the box with plastic so that no moisture could escape. A small slit was made in the plastic so we could slide in a relative humidity probe so that we could monitor the conditions.
We sat patiently and watched as the humidity went up and up, monitoring it carefully with a probe. Because of the sealed conditions the humidity steadily rose from 55% to around 85 % within an hour. We then removed the item from the sealed box and attempted to remove the item from the leather. This was a tense moment as we knew the leather would be delicate put with the minimum of force the item slipped about from the leather than had held it captive for so long. I may be a strange soul, but gently sliding out the anemometer was incredibly satisfying. We can now prepare the item for display and it will be on display
All in all, a good day's work. Amazing what you can do with a box, a cake rack and some plastic sheeting