Treating Mouldy Objects - Planning - October 17, 2012

October 17, 2012

Several objects stored in the Kings County Museum started showing evidence of mould growth.  This was discovered by the curator and immediately dealt with.  The curator inspects objects at least twice every year watching for possible mould growth in order to catch it and deal with it before it spreads.  This is an ongoing issue in many museums and requires extra diligence.  All objects must be quarantined when they are donated to the museum for a period of time usually one or two months.  They are examined regularly and only enter the permanent collection when they show no evidence of mould or insects.  In Nova Scotia (as in United Kingdom) where the average annual relative humidity (RH) is over 80% mould growth can happen at any time.  General collections of objects are best stored at 65% RH.

I put together a list of steps to take in terms of cleaning up this mould outbreak.  The steps are based on a combination of advice from the Senior Conservator at Nova Scotia Museum, internet research, and my studies at the university.  The objects were bagged in plastic and stored in a freezer then removed and kept in room temperature still bagged for at least 24 hours beforehand.  The following steps were discussed and approved by the curator before proceeding:

1. hang up the objects on a line outside in direct sunlight preferably with a bit of wind for 6 to 8 hours - make sure that they are not hung up near intakes for air conditioning or open windows into the building
2. brush off the objects with a soft, small paint brush first one direction and then the other - repeat this step after 2 or 3 hours - when done, brush must be soaked in bleach and water solution for at least 20 minutes, rinsed and dried OR thrown away
3. mix Orvus soap (discussed in previous post) with distilled water in a small bowl using only one teaspoon or less of soap, thoroughly mix it
4. using a natural sponge lightly damp wipe the object with the Orvus solution first one direction and then the other - sponge must be soaked in bleach and water solution for at least 20 minutes and dried when done OR thrown away
5. using a natural sponge lightly damp wipe the object with distilled water first one direction and then the other
6. repeat above step
7. hang up the damp objects on a line outside in the sun for several hours until thoroughly dry (again, windy would be best

Note: latex gloves and a face mask were used for all steps where mould spores may be present. 

The objects in question were a collection of military hats primarily from World War II but of particular interest is one from the Boer War which is over 100 years old.  Below is a photograph of all of the objects.  Later photographs will show them in more detail.