JAIC 1997, Volume 36, Number 2, Article 4 (pp. 143 to 150)
JAIC online
Journal of the American Institute for Conservation
JAIC 1997, Volume 36, Number 2, Article 4 (pp. 143 to 150)

A NEW TECHNIQUE FOR DETERMINING THE DEPTH OF PENETRATION OF CONSOLIDANTS INTO LIMESTONE USING IODINE VAPOR

RAKESH KUMAR, & WILLIAM S. GINELL



2 MATERIALS


2.1 CONSOLIDANTS

The following solutions, emulsions, and dispersions were tested as consolidants in varying concentrations:

  1. Rhoplex AC-33: acrylic emulsion in water
  2. Rhoplex AC-630: acrylic emulsion in water
  3. El Rey Superior 200: acrylic emulsion in water
  4. Carboset 514-H (acrylic copolymer dispersion) + ERL-4221 (3,4-epoxy cyclohexyl methyl-3,4-epoxy cyclohexyl carboxylate): acrylic-epoxy solution in isopropanol/water
  5. Eponex 1510 (hydrogenated bisphenol-A-epichlorohydrin) + Jeffamine T403 (polyoxypropylenetriamine): epoxy in isopropanol
  6. Bayhydrol 121: polyurethane dispersion in water
  7. Acryloid B-72: acrylic polymer in toluene
  8. Conservare SS-OH: tetra ethoxy silane in 2-butanone and 2-propanone
  9. Conservare SS-H: tetra ethoxy silane & alkoxysilane in 2-butanone and 2-propanone
  10. Polyvinyl acetate (AYAF): polyvinyl acetate in toluene


2.2 STONE

Indiana and Xunantunich limestones were used for this study. Indiana limestone is a beige-colored, homogeneous, fossiliferous limestone. Chemically and mineralogically it is almost pure calcite with a small amount of quartz, hematite, and magnesium. The porosity of this limestone is ∼18.6 %.

The Xunantunich (Belize) limestone is of marine origin and is inhomogeneous. Chemically and mineralogically it is a fine-grained, almost pure, calcite with minor amounts of magnesium, iron, aluminum, and silica impurities (<2%). The hardness varies with the distribution of soft and hard calcite. The porosity of this type of stone, as measured by mercury intrusion porosimetry, varies from 26 to 56%.


2.3 IODINE VAPOR

Iodine vapor was generated by room temperature sublimation of solid iodine in a closed glass chamber.

Solid iodine and iodine vapor are hazardous materials and should be handled with care and in accord with Materials Safety Data Sheet (MSDS) recommendations.


Copyright � 1997 American Institute for Conservation of Historic and Artistic Works