Historically, the varnishes had the aim to protect the bowed musical instruments by the external agents and to confer them an aesthetic value. During the 17th and 18th century, in Italy, the bowed instruments, especially violins, were generally covered by a layer of varnish made with several natural materials such resins, oil or hide glue: i.e., instruments by the great violin maker Antonio Stradivari were covered often with a layer of varnish made of linseed oil and colophony in the ratio 3:1, respectively. The main aim of this work was to study the modifications that occur in those kinds of varnishes, after exposing them to some factors of degradation. In order to study the different properties of organic coatings and their suitable compositions, different mixtures of linseed oil and colophony were recreated in the laboratory following an ancient recipe: linseed oil and colophony were mixed together with different ratios (50/50 and 75/25, respectively) and then, they were applied on Maple wood samples and on glass slides for experimental purposes. In order to investigate the different external factors which cause the varnish layer degradation, samples were analyzed by different techniques before and after different ageing processes (thermo-hygrometric cycles, exposition to UV lamp and to acid vapors). Out of strong experimental evaluation, all the results suggested that the composition of 75/25 (oil: colophony) is much better as a varnish for musical instruments.
Experimental characterization of oil-colophony varnishes: A preliminary study
WETHTHIMUNI, MADUKA LANKANI;Canevari, Claudio;LICCHELLI, MAURIZIO;MALAGODI, MARCO;ZEFFIRO, ALBERTO
2016-01-01
Abstract
Historically, the varnishes had the aim to protect the bowed musical instruments by the external agents and to confer them an aesthetic value. During the 17th and 18th century, in Italy, the bowed instruments, especially violins, were generally covered by a layer of varnish made with several natural materials such resins, oil or hide glue: i.e., instruments by the great violin maker Antonio Stradivari were covered often with a layer of varnish made of linseed oil and colophony in the ratio 3:1, respectively. The main aim of this work was to study the modifications that occur in those kinds of varnishes, after exposing them to some factors of degradation. In order to study the different properties of organic coatings and their suitable compositions, different mixtures of linseed oil and colophony were recreated in the laboratory following an ancient recipe: linseed oil and colophony were mixed together with different ratios (50/50 and 75/25, respectively) and then, they were applied on Maple wood samples and on glass slides for experimental purposes. In order to investigate the different external factors which cause the varnish layer degradation, samples were analyzed by different techniques before and after different ageing processes (thermo-hygrometric cycles, exposition to UV lamp and to acid vapors). Out of strong experimental evaluation, all the results suggested that the composition of 75/25 (oil: colophony) is much better as a varnish for musical instruments.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
