This workshop provides an overview of the principles of stain reduction of ceramics. Lectures, including cleaning theory, materials and application methods, and shared case studies from years of practical experience, are paired with hands-on sessions that enable participants to experiment with common reagents and poultice materials on stained ceramic test pieces. By the end of the workshop, participants will have a solid understanding of the chemical and physical properties at play during stain reduction treatments and feel comfortable exploring these treatments in their own conservation labs.
Participants need only bring themselves and an open mind. However, if you have a stained ceramic at home you would like to test, these are welcome!
Tentative Schedule:
Day 1
9:00 – 10:00 am LECTURE Ceramics Cleaning Theory
This lecture focuses on cleaning theory at the molecular level and addresses concepts of surface charge, ion exchange, pH, chelation, poulticing, bleaching, and solution concentration.
10 :00– 10:30 am TEA BREAK
10:30 – 11:30 am LECTURE Materials for Stain Reduction and Application Methods
This lecture introduces the materials we use and those that we will use during the workshop, supported by the previous lecture as to why we use them. It will also discuss considerations for how we use each one and will segue into the hands-on portion of the day.
11:30 am – 12:00 pm QUICK PRACTICUM Spot tests
Apply small spot-test applications of Kaydry tissue dampened with different reagents to each person/group’s test ceramic before lunch; results can serve as an indicator for which chelator will likely work best for that ceramic.
12:00 – 1:30 pm LUNCH BREAK
1:30 – 2:30 pm PRACTICUM Testing poultice materials with various reagents
Break into groups and have set materials to try out and a general plan of how to go about it. We will first look at the results of the morning’s spot tests, which will help inform testing plans.
2:30 – 3:00 pm DEMONSTRATION Making agarose gel
3:00 – 3:30 pm TEA BREAK
3:30 – 4:30 pm CONTINUE PRACTICUM, wrap up for day
Day 2
9:00 – 10:30 am DISCUSSION AND CONTINUE PRACTICUM
Applied poultices from day prior should be dry; we can remove these and discuss initial observations. Then, follow select areas up with a second poultice (e.g., bleach application) using quick-drying poultices to observe results in the afternoon.
10:30 – 11:00 am TEA BREAK
11:00 am – 12:00 pm LECTURE Case Studies
A presentation of case studies, talking through various challenging stains and differing ways of approaching them.
12:00 – 1:30 pm LUNCH BREAK
1:30 pm – 2:30 pm DISCUSSION
Quick-drying bleach poultices can be removed, and we will meet as a group to discuss overall observations and takeaways.
Image copyright: John Schneck.
