Investigating Fluidizing Dripping Pink Commercial Paint on Van Hemert’s Seven-Series Works from 1990–1995

A painting from the Seven series by Frank van Hemert made between 1990 and 1995 was starting to show fluorescent exudates and drips after about 7 years. Paint samples were investigated with analytical mass spectrometry, solid state NMR, imaging FTIR and SEM-EDX. Fluorescent exudate of fluidised paint compared to rubbery paint underneath showed differences in FTIR and MS characteristics related to the distribution of polar acylglycerides with ester bonded and free azelaic acid groups. The oil in the Schmincke Norma Fleischfarbe nr 213 tube paint used by van Hemert consists mainly of semidrying oil giving a Drying Index of 72. Imaging FTIR identified aluminium soaps in fluorescent vesicles in the solid rubbery paint. Solid state NMR indicated that these aluminium soaps are degraded and consist mainly of aluminium hydroxy-monostearates. DTMS and ESIMS showed apolarity inside the rubbery paint compared to the exuding material. The drying of the paint produced high relative amounts of smaller oxidised fractions that could not be retained in the paint mass as aging progressed. A physical separation resulted in more polar fractions. The fluorescence of these exuding fractions can be used a tracer for failing or impending failing of oil paint.