Respecting the Service / Respecting the Surface: Treatment of the Copper Alloy USS Utah Ship’s Bell and the Development of Treatment Procedures for Historic Metal Surfaces in the Naval History and Heritage Command Conservation Branch

Karl Knauer, David Krop, Melissa Swanson, Yoonjo Lee, and Abigail Preston


Naval History and Heritage Command (NHHC) conservators have been developing methodical, proactive procedures for approaching the treatment of ships’ bells in response to frequent requests for display. Borrowers include Navy museums and facilities as well as a wide range of civilian institutions around the globe.   The Navy’s collections include over 1500 ship’s bells and bell-related objects.  Bells are symbolically important artifacts often used to convey the histories of ships, their service members, and significant battles.  These bells are typically cast copper alloys; others are iron alloys, have nickel or chrome plating, or have painted surfaces. The range of unpainted metal surfaces observed on these bells includes highly polished surfaces, applied patinas, patinas of age, uneven areas of corrosion, and extensive overall corrosion. The treatment of the USS Utah ship’s bell represents a case study in developing and utilizing an adaptive treatment protocol. The 775-pound copper alloy bell was recovered from the submerged hull of a US Navy battleship sunk during the attack on Pearl Harbor, December 7, 1941. After recovery, the bell was likely on open display for sixty years. Unfortunately, scant records convey the post-salvage life of this object. When transferred to NHHC’s Conservation Branch in 2017, the bell suffered from tenacious corrosion products and excessive yet inadequate mounting hardware.  Treatment necessitated resourceful, creative approaches to achieve stabilization including an aesthetically integrated surface and appropriate lifting hardware.  This conservation treatment prepared the bell for a rededication ceremony at the University of Utah honoring the 76th anniversary of the Pearl Harbor attack. The Conservation Branch’s evolving perspectives on metal surface treatments as well as practical limitations were influential in equipment acquisition and setting up workspaces for the official debut of the conservation laboratory.  Potentially novel treatments include the use of zinc oxide as a polishing compound and potato starch micro-abrasive blasting for the selective removal of corrosion products. 

2020 | Online | Volume 27