Molly McGath, NCPTT summer intern, is studying interactions between air pollution and limestone treated with commonly used chemical stone strengtheners, Conservare OH100 and Hydroxylating Conversion Treatment (HCT), both distributed by Prosoco, Inc. Her experiments will help preservationists better understand the long-term strengths and weaknesses of using chemical treatments on cultural stone. She is looking at whether sulfur dioxide deposited on stone under dry conditions chemically binds and changes the stone to gypsum or slowly desorbs from the stone over time.

National Center for Preservation Technology and Training
645 University Parkway
Natchitoches, LA 71457

Email: ncptt[at]nps.gov
Phone: (318) 356-7444
Fax: (318) 356-9119