En jämförelsestudie av träprover som konserverats med olika metoder Förändringar i färg, vikt och dimension

Abstract

This essay focuses on waterlogged wood that was conserved in the late 1980s. It was the group Wet Organic Archaeological Materials (WOAM) of the International Council of Museum committee for conservation (ICOM-CC) that wanted to compare various conservations methods around the world. Wood samples of different ages and degree of decomposition were sent to different conservation laboratories which performed their specific conservation method on the wood samples. They preserved wood in different polyethylene glycol (PEG) methods or with resin. Three examples of the wood: samples from Norway preserved in 20% PEG400 and 90% PEG4000, and samples from Japan preserved in 60% PEG with tert-butanol. The results of the conservation treatments were documented. This study aims to evaluate the results of the conservation treatments by measuring the changes in color, weight and dimension in the samples. The color changes were measured with a Minolta Chroma colorimeter where delta E value is calculated to see how much the color of the samples has changed between 1992 and 2015. Comparing between the weight in 1989 and 2015 were made. Also a dimensional change was investigated. The goal of this paper has been to examine the changes and determine which treatments in general rendered a good result for the conserved object. The results from the dimensional changes show that the wood samples (both hardwood and softwood) have shrunk with less than one percent since the end of the 1980s while the weight changes show variations of only two percent. Consequently, there were no significant changes in weight and dimension. At the last measurement in 2015, all wood samples showed a significant color change when compared to the reference samples except one. In contrast only five of the samples indicated a significant color change when compared to what each showed in 1992 with 2015.