Air Abrasive Units
Antarctic Heritage Trust Conservator Conor Tulloch shows us some of the tools and equipment used in the winter conservation laboratory at Scott Base
Air abrasive set-up at Scott Base (AHT)
Our winter conservation laboratory at Scott Base in Antarctica is full of tools, materials, and equipment. The biggest workhorses of the lot (besides the conservators themselves!) have to be the air abrasive units. These are mostly used to abrade away rust and aged conservation coatings on iron objects by selectively blasting their surfaces with fine powder. The team are using Resko Airblaster units from Germany.
Compressed air is piped into the units where it picks up an abrasive powder before being ejected out a nozzle operated by one of our conservators. Treatment is done inside an abrading chamber to contain the fine powder, while an extractor unit attached to each chamber removes the excess powder so there isn’t a blizzard in a box whenever they’re used. Work that is usually long and laborious by hand can be completed with a fraction of the time and effort.
For the most part, the team is using sodium bicarbonate (baking soda), as the powder is tough enough to strip resin or wax coatings and corrosion, but gentle enough that it doesn’t damage the solid iron beneath. For the really heavy, encrusted corrosion though, a harder aluminium oxide powder is used.
With the surfaces of these objects returned to uncorroded metal, they are ready for the next step in their conservation treatment. But that’s a story for another post!
Head of sledgehammer before (left) and after (right) removing corrosion and old coating with air abrasion (Conor Tulloch/AHT)
Inside the abrading chamber (Conor Tulloch/AHT)
