Post-conservation Carbonate Blooms on a Bronze Gun from the Alamo

Summary

This is an abstract from the session entitled "Conservation of Archaeological Materials from Submerged Sites", at the 2024 annual meeting of the Society for Historical Archaeology.

In 2008, a Spanish-made 4pdr bronze cannon thought to have been used to defend the Alamo in 1836 was donated to the Alamo Museum, which sent it to the Conservation Research Laboratory at Texas A&M University for conservation prior to display. After 12 years, it began to exhibit new corrosion, and was sent back to the lab for retreatment in July of 2020. After undergoing the same conservation process as it had previously, a previously unseen white precipitate formed on the surface. Analysis of the powder showed it to be a mixture of carbonates and copper hydroxide, indicating that it was likely occurring due to the electrolyte used. To address this, a series of small like-composition ingots were put through the same process to mimic the precipitate, then various acids were tested to identify an appropriate in situ method for neutralizing the carbonate blooms without damaging the metal.

This Resource is Part of the Following Collections

• Society for Historical Archaeology 2024   •
• Conservation of Archaeological Materials from Submerged Sites

Keywords

Individual & Institutional Roles

Contact(s): Nicole Haddow