Hi! I’m Meg McNall
During my final two years as an undergraduate at Princeton, I explored the role of salt crystallization in the deterioration of limestones and polymer treatments which could be used to lower crystallization pressures and prolong the life of building stones. This research culminated in my senior thesis, "Controlling Crystallization Pressure Through Surface Modification".
Now returning to Princeton as a Ph.D. candidate, I hope to answer the final questions about these polymer treatments, as well as develop similar treatments for use on sandstones. Additionally, I hope to explore the interaction between salt crystallization and other mechanisms of damage, including swelling clays.
The pictures below show damage to the Howden Minster in Howden, East Yorkshire, England (see the map at the bottom of the page). The building is made of a dolomitic (magnesian) limestone and is being destroyed by precipitation of magnesium sulfate salt. There is possibly additional deterioration related to clays in the stone.
My work is supported by the Getty Conservation Institute and the National Center for Preservation Training and Technology (Award MT-2210-09-NC-03).
Magnesian limestone at Howden Minster damaged by magnesium sulfate salt. The flaking suggests a possible role of clays in the stone.
Poster presentation on Jan 11, 2008
We have begun tests to evaluate the reasons for the susceptibility to salt damage of stones from the Howden Minster in the UK