Testing making a KSG/silicone solvent/pH adjusted water emulsion. Image courtesy of Karissa Muratore.
Workshop taught by Chris Stavroudis, Private paintings conservator in Los Angeles, CA, on the Modular Cleaning Program (MCP), emulsions/microemulsions, advanced aqueous cleaning, surfactant chemistry, gels, and cleaning acrylic paintings.

This workshop was completed at the conclusion of a semester long cleaning course taught by Richard C. Wolbers, Matthew Cushman, and Joan Irving. The workshop consisted of three theory days, where Chris lectured and moderated open discussions on cleaning related topics, and two practical days where participants used the MCP to develop, prepare, and test cleaning solutions. The final 1.5 days of the workshop were allocated to one-on-one time with Chris to discuss individual cleaning class treatment projects.

Testing custom made KSG350z cleaning gel on an acrylic painting, c. 1960. Image courtesy of Dr. Joyce Hill Stoner.

Lecture/discussion topics began with an introduction to cleaning theory and advanced aqueous cleaning theory and were based on the fundamental information taught by Richard C. Wolbers in our first year chemistry course. Topics included:

  • pH adjusted water: how to prepare and why rinsing is a critical step
  • Buffers, chelators, and ionic strength: how to control and utilize these variables
  • Surfactants and resin soaps: when it is appropriate to use them
  • Non-ionic and anionic gels: how to choose which gel to use and the benefits and drawbacks of each

The second set of lectures/discussions was based on the Modular Cleaning Program, which Chris developed and maintains. The MCP utilizes five variables: pH, chelator, buffer, surfactant, and gel. Chris provided instructions on how we can use the program to develop and test unique cleaning solutions using case studies as examples.

I was particularly interested in learning about silicone solvents, which Chris introduced in his solvents lecture. Silicone solvents are most often used as a hold-out for porous structures, but are being explored as a solvent in their own right since they have very little polarity and are 100% volatile. The solvents lecture was a precursor to the emulsion lecture where we discussed the endless possibilities of emulsions and microemulsions including recent advancements and new technologies.

Various cleaning tests on an acrylic painting (c. 1960) by Dr. Joyce Hill Stoner.

The practical days permitted participants to practice preparing pH adjusted water, gels, and emulsions. We tested these solutions on study paintings (acrylic and oil).

During the last day of the workshop, Chris was available to consult on our treatment projects. My cleaning project is a pair of c. 1968/9 Christian Dior patent leather heels from the Philadelphia Museum of Art study collection. Prior to Chris’ arrival, the Winterthur Conservation Science staff and I conducted Fourier Transform infrared spectroscopy (FTIR) and pyrolysis gas chromatography-mass spectrometry (pyGC-MS) to identify the synthetic coating (polyester/polyurethane) and deterioration product (adipic acid). Chris aided Lara Kaplan, supervising conservator, and me in developing various cleaning solutions to test. His insight into cleaning was invaluable and, although we have still not solved the cleaning problem, we know that a solution will be found (or made!).

Chris Stavroudis teaching workshop participants how to use the Modular Cleaning Program (MCP). Image courtesy of Karissa Muratore.