CONSERVATION PROCESS CONTROL LABORATORY

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Main function of this laboratory is to monitor the absorption of the Polyethylene glycol [PEG] into the wet wood where it replaces the water. Monitoring will be done by measuring the density of the solutions throughout the treatment process.

Densities are measured using a hydrometer.

The glass tank is a constant temperature bath to ensure accuracy of density measurements. The rate of absorption will determine the size of the increases in the PEG strength - overseas experience indicates these should be in small steps.

The whiteboard indicates progress as percentages - our target for the 1st stage is 40% for the PEG 400 grade. A 2nd stage process applied only to the material in the Gallery uses a different grade [PEG 3350] in a heated tank to lift absorption to 70%.

The oven is used to dry out wood samples to determine their moisture content. Once the second stage is complete the wood will be slowly dried out and the laboratory oven and constant weighing of samples will be used to monitor the rate and completion of drying.

Conservators will continuously monitor the process both at the Old Bank and at this Gallery.