CO2 Snow Cleaning and Art and Artifact Cleaning
In recent years, there have been presentations and publications characterizing CO2 snow cleaning for art cleaning. One important aspect is the sensitive nature of cleaning art; they are irreplaceable, likely delicate, and have high value. L. H. (Hugh) Shockey of the Lunder Conservation Center, Smithsonian American Art Museum demonstrated lint removal from Beth Lipman’s "Bancketje" (2003 - a contemporary glass structure) and an unknown haze removal from Robert Morris’s "Model" (1967 - a polymer based sculpture).
In September, 2015, the Lunder Conservation Center hosted a symposium on CO2 snow and pellet cleaning directed at art cleaning. Three speakers covered CO2 snow cleaning: Robert Sherman on CO2 snow cleaning processes, Hugh Shockey on the above examples, and Nancy Odegaard of the Arizona State Museum, University of Arizona, on cleaning woven baskets. Links are in references in 2012
The three talks covered how CO2 snow cleaning works, and what it can and cannot do for art cleaning. Experience by Sherman has shown CO2 snow can clean glass, metal, jewels, polymer, and ceramics materials. Shockey and Odegaard, as experienced conservators, gave excellent examples. Overall, CO2 snow cleaning can remove lint and particle debris, hydrocarbons, fingerprints, oils, polishing residues, wax, soot, and organic contamination. All these items are weakly bound to a surface. Permanent coatings, such as lacquer and paint, will not be removed unless they are compromised. Most patinas will stay intact. Old oil paintings are not suitable for cleaning.
The main concern with CO2 snow cleaning is potential damage and moisture condensation. The samples must be secured while cleaning; otherwise, they can be blown away. Moisture condensation happens when the cold CO2 snow strikes a poor thermally conductive surface such as glass. Moisture forms on the surface and can interfere with cleaning. To counter this, Hugh Shockey used a compressed air heater attached to a dual gas unit made by Applied Surface Technologies. This device can warm a surface to about 120 - 140 degrees F and can counter most moisture issues. Nancy Odegaard, working in a very dry environment, cleaned weaved baskets without any thermal input. Results were quite acceptable for both projects. Sherman has introduced new units for this field along with a commercial compressed air heater system for use with CO2 snow cleaning.
Many examples exist now, and they are listed here and are shown on the Art and Artifact Examples page.
2- Wax Removal
3- Dirt Removal
4- Soot Removal
Equipment and Pricing
Our initial approach is to use the units shown on the equipment page. For the Art units, these units will come with three nozzles. The venturi nozzle will be on the unit and this nozzle works with either liquid or gas CO2 feed. Two additional nozzles come with the units, one is a low flow low velocity nozzle; the other is a high flow, more aggressive nozzle. The latter two nozzles require a liquid CO2 feed. See price page or equipment page for unit descriptions. The extra nozzles give the user a full range of CO2 snow cleaning abilities for this community.
Pressure Gauge - $200.00
CO2 Meter - $149.00
In line Compressed Air Heater with modified K1 or K4 unit- $1695.00 - Details are here