Do Not Migrate

Here are notes from three presentations I found interesting.  I hope you’ll find them interesting, too.

Interior Stone Cleaning at Saint John the Devine: practical and logistical considerations — Claudia Kavenagh

While construction on the church was started in the 19th century, it is still not completed.  During construction in 2001, a fire broke out that damaged the interior of the church.  Conservation treatments were required.  The nave was scaffolded and a rolling platform was created to reach the ceilings.  Arte Mundit was used to clean the fire damage to the nave and interior of the church of Saint John the Devine.  Contractors used spray application of the material to clean.  At times removal of Arte Mundit was difficult.  The cleaning method needed to be sequenced properly in order to have appropriate swell times.  It was important to segregate the work areas.  Arte Mundit also can remove certain types of paint.  Paint surfaces and stained glass had to be covered.  Arte Mundit had to be fully cured before being removed within 48 hours of the application. The cleaning was successful, however Arte Mundit can leave residues that are not visible to the naked eye but can be found using ultraviolet light.  Research is needed to determine the long term effects of this residual latex product.

Winter Shelters for marble sculptures for the Schossbrucke Berlin: climatic constraints — Siegfried Siegsemund

Based on research, Siegfried Siegsemund shows that cycling humidity and temperature fluxuations lead to significant thermal-hygric deterioration of the marble sculptures.  The data supports the use of winter coverings to protect the sculptures from temperature fluctuations, humidity cycles, and ice formation.  The information was used to design winter coverings. Next he monitored conditions between uncovered and covered monuments over time. He advocates the winter covering and recommends educational  panels for the public.

Developing an integrated decision making system for the assessment of cleaning interventions on marble architectural surfaces — E.T. Delegou

This very thorough and complex presentation presents a decision making system for cleaning marble architectural surfaces based on GIS graphical user interface. The system includes a database that contains attribute data and a fuzzy logic model with the cleaning requirements.

Fuzzy logic starts with a set that does not have a clearly defined boundary.  the  fuzzy logic models goes through three major transformations.

The cleaning assessment criteria is defined and conditions are followed using Scanning electron microscopy, color measurement (total color difference delta E), and laser profilometry textures (roughness Rq, and ratio of actual to protected areas.).

Next accepted indices are entered as fuzzy logic sets.  “Medium” fuzzy sets are the acceptable parameters.  The output parameters include four choices. from no cleaning to optimum cleaning.

The tool was demonstrated for case studies in Athens Greece.  Pilot cleaning interventions were tested with different cleaning methods, including ion exchange resins, abrasive cleaning, etc.  The locations of the test areas were entered into the GIS system.  The results were the input data into the fuzzy logic model.  The result was a conservation intervention map that specifies one of the cleaning indices.  The conservator can choose appropriate cleaning approaches based on the output map.

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

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