Continuing work on my Steneosaurus obtusidens specimen I found it to have been more affected by pyrite oxidation than I had originally thought. Other than consolidation my approach was to handle the specimen with extra care in the affected regions – even brushing over with a soft brush would cause further deterioration – cracking and powdering.
I started to fill gaps in the specimen this week. I would be using micro-balloons in B-72 to make the filler, but found it difficult to weigh up the options between the types of micro-balloon to use. The micro-balloons are used to thicken the adhesive into a “paste” that will fill out a gap and hold in place. As the adhesive is B-72 the fills can be removed using acetone if needed. After testing the options available to me I choose a very fine micro-balloon powder that would make a smooth mix. However the downside is that the filler being white would lighten when dried so I would have to mix a pigment colour accordingly.
Using acrylic paints I mixed a pigment to match the existing fills – they would inevitably appear new in the specimen as they had been aged by dust and time as the others had been.
I was not a great fan of the micro-balloon B-72 filler. It was difficult and messy to apply and thickened too quickly when exposed to air – I felt I needed 3 hands to use it! In the cracks it expanded out and became aerated within so wasn’t filling the gap as needed. Over the weeks I continued to struggle using it, continuously taking advice and testing different application techniques – I decided I just didn’t like it as I was continually frustrated when using it and unhappy with my work.
It was Pest Odyssey this week (I didn’t attend – far too expensive!) and some of the speakers held a seminar at the Natural History Museum to run alongside (which I did attend – free!). The subject was pest management in Northern American institutions. I found the lecture on the building of the Natural Heritage Building (NHB) in Canada particularly interesting. The building was built with pest management in mind; from the landscaping to the flooring. Ideas such as creating a declining slope away from the building and a vegetation free perimeter showed the level of detail they considered in the planning. At the same time it came at a huge expense to implement and maintain these measures – particularly as pests are not the main cause of damage to museum objects. It’s also a wonderful once in a lifetime opportunity to take advantage of a new building being built and many of the measures could not be effectively applied to old buildings.