Langzeit-Löslichkeit von Störleim

Tatsache oder Märchen?

Abstract

Long-Term Solubility of Sturgeon Glue: Fact or Fairy Tale?
Sturgeon glue is prepared from the swim bladder of the sturgeon, a large fresh-water fish. Despite the fact that sturgeon glue is very widely used in Germany and elsewhere by conservators of paintings and polychromy, there is very little information available concerning its basic physical properties, such as ageing characteristics, compatibility with other materials and reversibility. Moreover, the origin and processing methods used for the preparation of commercially-available swim bladders are usually unknown. In this paper, the results of research into two aspects essential for conservation use are presented: the effects of ageing of sturgeon glue and its solubility (thus, reversibility) after ageing.The glue used for this study was produced from the fresh bladders of locally farmed sturgeons. Freshly extracted swim bladders were examined for signs of pre-treatment, and the effects of these treatments on the glue made from them were investigated. The analysis of the artificially aged glues showed that they no longer dissolved completely in water. Additional experiments with commercially acquired swim bladders and with naturally aged glue sheets confirmed these results. During the course of the study, chemical reactions between glue and certain metals or solvents were observed. The resulting substances not only reduce the adhesive strength of the glue, additionally, these reaction products appear to be insoluble in water.