The importance of carrying out analytical studies before making conservation-restoration decisions is well known. In the case of metals and alloys, knowledge of the composition and patina of a work of art can determine the intervention required. However, access to analytical tools is often not an option due to the high cost of equipment and measurements.

Given the above circumstances, access to alternative material analysis techniques is becoming increasingly necessary. Freely accessible, easy-to-install software and low-cost "Do it Yourself" (DIY) equipment are options that meet the current needs and shortcomings of conservation-restoration in various areas of the profession.

This STSM's objective was to acquire expertise in the use of DiscoveryMat hardware and software and to enrich its database by adding new entries from the samples analysed in this context.

To this end, four copper base samples corresponding to sculptures made in 1970, 2022 and 2023 in Vila Nova de Gaia (Portugal) were studied. The samples were analysed using DiscoveryMat, measuring their corrosion potential (Ecorr) over time, in the presence of three solutions: Evian mineral water, 1% (w/v) potassium nitrate (KNO3) and 1% (w/v) sodium sesquicarbonate (NaSesq).

It was observed that the plots in Evian and KNO3 medium were more irregular than those in NaSesq medium, making data processing more complex.

Given the nature of the samples studied (large dimensions and irregular, rough surface texture), the feasibility of using DiscoveryMat on surfaces with these specific characteristics was verified. It became apparent that the effectiveness of the measurement required polishing of the area being analysed, which is often possible on hidden or inconspicuous areas of the sculptures.

This STSM was an excellent opportunity to learn about and experiment with a low-cost electrochemical instrument that can be very useful for the chemical determination of metallic materials.  In addition, the opportunity to work in parallel with two other colleagues, also recipients of an STSM but working on two different tools, gave me a good understanding of the assembly and operation of Pleco, as well as the process of creating a MiCorr sheet.

The experience gained in using DiscoveryMat will make it easier to disseminate this knowledge to the academic community and to conservator-restorers. This STSM should be just the first in a series of scientific cooperation between HE-Arc CR and the Research Centre for Science and Technology of the Arts - CITAR - UCP in the field of conservation-restoration and the application of low-cost, portable and easy-to-use devices such as DiscoveryMat and other devices such as Pleco and MiCorr, which HE-Arc CR is currently developing.

Full report

Illustration of STSM tasks