This blog post by Rowena Hartley from the Museum’s Move Project Team looks at the cleaning processes involved when moving museum collections.
Unlike the majority of people the favoured habitat for museum objects are large windowless rooms with regular, slightly chilly, temperatures and very little excitement. Here at MHS our collection is no different and, much like the attics, cellars and under-the-bed stores we all use at home, they come with their very own brand of excitement often involving a fair amount of dust and some multi-legged creatures along the way. So as part of our work for the Move Project we are ensuring that every object is in peak condition, clean and pest free for the journey to its new store.
After just a few years in a museum store, or attic or cellar for that matter, even the best protected items develop thin layers of dust from the building and the objects around them. As unsightly as this is, it also poses a much greater threat. Dust, when left, can become adhered to the object causing the surface to dull and over time encourage mould and corrosion to develop. Dust can even attract bugs and pests who feed on the dust particles and then upon the objects themselves. Sometimes the pests are brought into the store in the objects themselves, it only takes one or two unseen eggs for an infestation to begin. Here the chilly environment helps to slow down or even dispatch any bugs who’ve decided to join us. Whilst this doesn’t make for the cosiest working environment it helps to protect the objects from any creatures feasting on them. One common culprit we have found is the wooly bear which likes to feed on the fabric and leather in our microscope cases. The cold appears to have successfully chased many away, as only the casings are left. The permanent damage which dust and pests pose to these objects is why we take the time to remove these threats, but in doing so we have to ensure we don’t do more harm than good.
Most objects we work with only require a dry clean, this is where we use products such as dust-cloths, brushes, museum vacuums and latex sponges to gently lift dust from the surface of the object. This may sounds fairly harmless but many of the objects are well over a hundred years old and incredibly fragile, so we have to take great care to be gentle and remove only the dust; sometimes it can look like we haven’t cleaned the object at all but we have removed as much of that dust as we safely can. We even have to be careful with the products we do use, making sure they are made from conservation friendly materials and even washed in specialist washing up liquid to make sure we’re not responsible for adding any harmful materials. Even the vacuum cleaner is variable so that on fragile objects, such as textiles, we can put it on the lowest setting and not risk lifting any loose threads up from the surface. However there are times when we have to balance the non-invasive approach with ensuring the object is in a safe and stable condition, this is where we tend to get more aggressive with our cleaning methods.
Aggressive cleaning is perhaps a little misleading, but like most people’s spring clean it involves washing up liquid, insecticide and alcohol, only we maybe don’t get to enjoy the last one as much as we’d like. These products may sounds fairly run of the mill but as all of them include some strong chemicals we have to use them sparingly as even just introducing water to an object can risk the material expanding and cracking. There have been a few occasions so far in the move where an object has needed this bit of extra cleaning, despite the risks it may pose.
Infestations are one of these occasions as pests can cause a large amount of damage by eating away at objects, so they have to be treated immediately and quite harshly. We have faced two notable infestations, one was a family of moths which had taken to living in the case for two induction coils (pictured above, Inv.11697), and once the case was opened they decided to make their presence known. The other infestation was a little more subtle, it was only a few small holes and the tell tale trails of fresh sawdust which hinted at the woodworm hiding in a series of geometric woodblocks (Inv.11532). Both of these infestations had to be dealt with in the same way with the objects being treating with a water-based insecticide called Constrain, which with its neutral pH, avoids the use of any especially harsh chemicals.
To treat the infestation separate work stations were setup to avoid any risk to other objects from the pests or from the insecticide. The objects were sprayed with Constrain and isolated so the spray could take effect, the woodblocks were stored in sealed plastic boxes but the case was too large and had to be wrapped in tissue then plastic so as to seal in the insects and the insecticide. After a few days the objects could be safely unwrapped with the infestation gone; the woodblocks were ready to be audited and packed but the case had to have a final clean to remove the frass and the moth carcasses which remained. Both are now clean, photographed and packed ready for the new store without any risk of further pest damage or of spreading their infestations to other objects.
However, pests are not the only threat as accumulated dust and mould can become irreparably attached to an object and obscure what is there. Whilst this is the practical reason for cleaning, it is also immensely satisfying seeing how much better it can look after a bit of care and attention. The mirrored display case below had a layer of dust and patches of mould staining the glass front, as well as the mirror at the back. Now this is where the alcohol gets involved! A cotton wool ball damp with alcohol was used to wipe away any traces of mould; this treatment alongside good air circulation in the new store should stop any spores from spreading and growing back. The alcohol was then wiped away with water so that there was no alcohol or mould residue left and then given a final wipe with a dust cloth. As you can see all of this took quite a few pieces of cotton wool to make it thoroughly clean, but the difference is an object which is in a good stable condition; this is why we clean every object, to keep it safe and stable for the next hundred years.
We have quite a few more objects to clean so if you’re interested in seeing this or some of our other work we will continue to post about the MHS Move Project on Inside MHS. You can also find us on Instagram and Twitter using #mhsmoveteam and #mhsstores.