A FRESH FACE FOR SAMUEL GOMPERS: METHYL CELLULOSE POULTICE CLEANING
Lisa A. Goldberg
1. Lewin, S.Z., and Elizabeth J. Rock. “Chemical Considerations in the Cleaning of Stone and Masonry.” The Conservation of Stone, I, International Symposium, Bologna, Italy, 1975, pp.343–368.
2. Hempel, K.F.B. “Notes on the Conservation of Sculpture, Stone, Marble and Terracotta.” Studies in Conservation, 13, 1968, pp. 34–44. George Wheeler. “The Treatment of a Marble Bust of Marcus Aurelius.” Student Papers, Art Conservation Training Programs, Cambridge, MA., Fogg Museum of Art, 1979, pp. 97–109.
3. Lehmann, Januz, “The Methodology for the Cleaning and Desalting of Stone Objects in Goluchow Castle Museum,” ICOM Committee for Conservation, 8th Triennial Meeting, Sidney, Australia, (1987), pp.487–492. E.A. Mel'nikova and M.N. Lebel, “Application of Polymer Films Removing Contaminations from Sculptures Made of Different Materials”, ICOM Committee for Conservation, 5th Triennial Meeting, Zagreb, Yugoslavia, (Paris, ICOM, 1978), pp. 10, 81–86.
4. This work was carried out in the Conservation Analytical Laboratory, Objects Laboratory, Smithsonian Institution under the direction of Susan West and Carol Grissom, while I was an intern from the Institute of Fine Arts, New York University Conservation Program. See CAL Report 4814. 1986.
5. I am grateful to Susan West (Meadville, PA.) for suggesting the use of a methyl cellulose poultice medium.
6. Test poultice films containing methyl cellulose, propylene glycol and fumed silica did not leave observable residues on glass sides or the marble surface. These surfaces were examined visually, in normal and ultraviolet illumination as well as under magnification.
7. Mr. Paul Angiolillo performed these analyses at the National Gallery of Art. Calcium levels were measured in test poultice films by focusing the beam on a visually particle free area. The poultice films were prepared using two different grades of methyl cellulose, containing varying quantities of glycerol, propylene glycol and polyethylene glycol 1000. More complete information and quantitative records can be found in his report on file in the Science Department, D.C.L. National Gallery of Art, Washington D.C.
8. Mr. Jack Randall, Pharmaceutical Coatings Department, Dow Chemical Company, Personal Communication, 1986.
9. The alkaline pH aids in raising the viscosity of the Methocel solution, as reported by Dow Chemical Company in Handbook of METHOCEL Cellulose Ether Products, Midland, MI, pp. 4.1, form no. 192-679-78.
10. Dow Chemical Company, Preparing a Solution of METHOCEL Step-By-Step, Product literature, form no. 192-958-85R.
11. Dow Chemical Company, Handbook of METHOCEL Cellulose Ether Products, (Midland, Michigan), p.4.3, form no. 192-680-78 recommends heating 1/5 to 1/3 the total required amount of water to 80–90°C. Water used in this treatment was heated on a hot plate to a temperature below boiling. The temperature was not monitored during the heating or dispersion stage.
12. Ibid., pp.6.11–6.12, form no. 192-687-78. This product has a thermal gelation temperature of approximately 48°C, at 2% concentration. At this temperature, the gel rise reaches its critical point and there is a sharp rise in viscosity. Additives like propylene glycol will raise the gelation temperature (not critical below approximately 5%). Increasing the concentration of the methyl cellulose by 2% lowers the gelation temperature of the A4C 10°C (see form nos. 192-687-78 and 192-412-75).
13. Cook R., and Martin Graham. “Preliminary Investigation into Discolorations Occurring in White Marble.” Recent Advances in the Conservation and Analysis of Artifacts, Jubilee Conference, Institute of Archaeology, University of London, London, 1987, pp. 359–364.
Cook, R., MartinGraham. “Preliminary Investigations into Discolorations Occuring in White Marble.”Recent Advances in the Conservation and Analysis of Artifacts, Jubilee Conservation Conference, Institute of Archaeology, University of London, 1987.
Dow Chemical Company, Handbook of METHOCEL Cellulose Ethers products, Midland, Michigan, continuously updated by form no. for each section.
Dow Chemical Company, Preparing a Solution of METHOCEL, Step by Step, Midland Michigan, form no. 192-958-85R.
Hempel, K.F.B.“Notes on the Conservation of Sculpture, Stone, Marble and Terracotta.” Studies in Conservation, 13, 1968, pp. 34–44.
Leback, C.“A Proposed Treatment for Brass and Copper Objects Coated With Aged Linseed Oil Films.”Student Papers, Art Conservation Training Programs, Winterthur Art Conservation Program, Delaware, 1976, pp. 104–127.
Lebel, M.N., and E.A.Mel'nikova, T.N.Cherniysheva, “New Methods Used in the Restoration of Stone Sculpture in the Hermitage Museum”, IIC Meetings, Bologna, Italy, 1986, pp. 122–125.
Lehmann, Januz. “The Methodology for the Cleaning and Desalting of Stone Objects in the Goluchow Castle Museum.”ICOM Committee for Conservation, 8th Triennial Meeting, Sidney, Australia, 1987, pp. 487–492.
Lewin, S.Z., ElizabethRock.“Chemical Considerations in the Cleaning Of Stone and Masonry.”The Conservation of Stone I, International Symposium, Bologna, Italy, 1975, pp. 343–368.
Mel'nikova, E.A., and M.N.Lebel. “Applications of Polymer Films Removing Surface Contamination from Sculptures Made of Different Materials.”ICOM Committee for Conservation, 5th Triennial Meeting, Zagreb, Yugoslavia, 1978, Paris, ICOM, 10/8/1-6.
Mel'nikovaE.A., S.A.Smirnov, M.N.Lebel. “On Gradual Removing Corrosion Layers from Metal, Stone and Ceramics.” ICOM Committee for Conservation, 7th Triennial Meeting, Copenhagen, Denmark, 1984, pp. 22,28–29.
Mora, P., and L.M.Sbordini. “Metodo per la rimozione di incrostationi su pietre calcaree e su dipinti murali.”Problemi di Conservazione, Bologna, Italy, 1973, pp. 339–344.
Orcsik, E.“Some Theoretical and Practical Problems of the Cleaning of Limestone and Marble.”ICOM Committee for Conservation, 7th Triennial Meeting, Copenhagen, Denmark, 1984, pp. 10,15–16.
Wheeler, G.“The Treatment of a Marble Bust of Marcus Aurelius.”Student papers, Art Conservation Training Program, Cambridge, MA., Fogg Art Museum, 1979, pp. 97–109.