Two methods for the stabilisation of excavated iron artefacts are storage in anoxic and in desicc... more Two methods for the stabilisation of excavated iron artefacts are storage in anoxic and in desiccated microclimates. A series of tests were run by the Conservation Department of the Japanese Institute of Anatolian Archaeology (JIAA) in Kaman, Turkey, to compare the efficiency of the anoxic and desiccating properties of the RP-A scavengers to the anoxic properties of the RP-K scavengers (Revolutionary Preservation System [RP System] manufactured by Mitsubishi Gas Chemical Company, Inc.) and to the desiccating properties of silica gel in Escal bags. In the first three tests, an archaeological iron artefact from the Kaman collection was included in the test bags. The primary goals of the first three tests were to compare the desiccation rates of RP-A and silica gel and the time required for the oxygen depletion to reach 0.1% by RP-K and RP-A. Each test compared one method of anoxic control with a target of <0.1% oxygen against one method of desiccation with a target of 10% RH. RP-A was found to reduce the RH in the bag to a 'safe' level for iron (i.e. 10% RH) in three hours from the start of the test, whereas the silica gel required 14 hours. The fourth test assessed the efficiency of anoxic protection of mild steel coupons (CR1020) afforded by the RP-K scavengers in 60% RH for corrosion prevention by exposing the coupons to 60% RH with and without RP-K scavengers. Environmental Scanning Electron Microscopy with Energy-Dispersive X-ray Spectroscopy (ESEM-EDS) was performed on three coupons on completion of test four. The goal of these tests was to determine the suitability of silica gel, the RP-K scavengers, and the RP-A scavengers to create environments with which to protect iron artefacts from corrosion. Based on the results of the four corrosion tests reported, RP-A can be recommended over silica gel for the immediate protection of archaeological iron from excavation. RP-K required 48 hours to reach <0.1% oxygen content based on the oxygen eye: it is recommended that a means more accurate than the oxygen eye indicator be implemented for monitoring oxygen depletion.
Two methods for the stabilisation of excavated iron artefacts are storage in anoxic and in desicc... more Two methods for the stabilisation of excavated iron artefacts are storage in anoxic and in desiccated microclimates. A series of tests were run by the Conservation Department of the Japanese Institute of Anatolian Archaeology (JIAA) in Kaman, Turkey, to compare the efficiency of the anoxic and desiccating properties of the RP-A scavengers to the anoxic properties of the RP-K scavengers (Revolutionary Preservation System [RP System] manufactured by Mitsubishi Gas Chemical Company, Inc.) and to the desiccating properties of silica gel in Escal bags. In the first three tests, an archaeological iron artefact from the Kaman collection was included in the test bags. The primary goals of the first three tests were to compare the desiccation rates of RP-A and silica gel and the time required for the oxygen depletion to reach 0.1% by RP-K and RP-A. Each test compared one method of anoxic control with a target of <0.1% oxygen against one method of desiccation with a target of 10% RH. RP-A was found to reduce the RH in the bag to a 'safe' level for iron (i.e. 10% RH) in three hours from the start of the test, whereas the silica gel required 14 hours. The fourth test assessed the efficiency of anoxic protection of mild steel coupons (CR1020) afforded by the RP-K scavengers in 60% RH for corrosion prevention by exposing the coupons to 60% RH with and without RP-K scavengers. Environmental Scanning Electron Microscopy with Energy-Dispersive X-ray Spectroscopy (ESEM-EDS) was performed on three coupons on completion of test four. The goal of these tests was to determine the suitability of silica gel, the RP-K scavengers, and the RP-A scavengers to create environments with which to protect iron artefacts from corrosion. Based on the results of the four corrosion tests reported, RP-A can be recommended over silica gel for the immediate protection of archaeological iron from excavation. RP-K required 48 hours to reach <0.1% oxygen content based on the oxygen eye: it is recommended that a means more accurate than the oxygen eye indicator be implemented for monitoring oxygen depletion.
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