Cleaning Countless Corals
The conservation lab is awash with coral at the moment. We are busy working through a list of 100 corals, ranging in size, type and condition. For the most part all are pretty dirty and many are adhered to old backing boards which are outdated and are not required in the new displays.
The old mount boards are acidic (pH 5-6) and the old adhesive is yellow and brittle and causing damage to the specimens. These were removed by softening the adhesive with warm water the residue removed from the corals with solvents.
We cleaned the corals in a multitude of ways. For the more robust hard, stony corals, specimens were immersed in baths of reverse osmosis water and allowed them to soak for a period. The specimens were then placed into a fresh bath and this was repeated until the dirt and salts were removed.
Specimens with a more embedded dirt were cleaned using a solution of <1% Synperonic A7 and reverse osmosis water. The solution was brushed onto the surface of the specimens to create a slight lather. The corals were then placed into a bath of fresh water for a prolonged period to ensure the synperonic solution was rinsed fully.
The more fragile specimens, namely the soft, horny corals, were cleaned using an airbrush and air compressor. The use of the airbrush allowed gentle cleaning of the delicate specimens with the airflow and the pressure fully controlled and adjustable. Where there was a more ingrained dirt the airbrush was used together with water in the paint reservoir. The gentle application of water under slight pressure removed a lot of the dirt and provided fantastic results. The corals now have a much better aesthetic and accurate colouring.