AIC's 45th Annual Meeting

This poster presents an assessment of dry ice blasting as a treatment method for the removal paint and corrosion from cast iron objects. Currently, The Batten Conservation Complex (BCC) within The Mariner's Museum and Park, Newport News, VA is responsible for the conservation of two British naval guns. The guns had originally been aboard vessels scuttled on the York River during the Battle of Yorktown in 1781 and were recovered from the river in 1934 through a partnership between The National Park Service, Newport News Shipbuilding, and The Mariners' Museum and Park. Since recovery, the guns have been painted several times, displayed in both indoor and outdoor settings (often adjacent to a saline/brackish environments), and exposed to fluctuating relative humidity and temperature. In early 2016, it was noticed that the protective paint coatings previously applied to the guns had failed, as well as visible evidence of recent corrosion. From these observations, it was determined that full re-treatment of the objects were necessary which included the removal of the paint coatings and surface corrosion followed by desalination. To avoid using large quantities of solvent and to significantly reduce active mechanical hands-on treatment time, alternate methods of paint and corrosion removal were investigated. Testing was conducted using both traditional abrasive media blasting using aluminum oxide as well as dry ice blasting following a procedure previously developed within the BCC for cleaning wrought iron. Results of testing identified dry ice blasting as a better choice for cleaning cast iron than aluminum oxide. Further testing was then conducted to develop a cleaning procedure for the removal of paint on the two British guns.