Szilágyi András (szerk.): Ars Decorativa 26. (Budapest, 2008)

Róza BRENNER: Conservation of a Pair of 18th Century Leather Boots Shrunken and Deformed at High Temperature

4. The pair of shrunken and distorted boots Dry cleaning The reddish soil dust stuck physically in the cracks of the boot surface was removed by hair-brush and careful weak vacuum cleaning through a screen, and the stains stuck to the leather surface were erased with a rubber. A piece of soft linen cloth stuck to an ear-cleaning stick and a rubber pencil were used to remove dust from the smaller creases. I tried to remove all the rubber chips left after use lest they should trigger off a decomposition process in the leather. Softening of the leather Like other organic materials, leather is in constant interaction with the environment, trying to achieve equilibrium with its humidity content. That was partly the cause for the hardness of the leather; hence this capacity was used for the softening. The pliability of tanned leather owes to the latent and free water the lack of which can be remedied - with the exception of extreme cases - by placing the object into an air space with relatively higher humidity. 5. Surface of the heavily shrunken and soiled leather with the corroded metal thread embroidery and sequins Beside the use of semi-permeable membranes, the most expedient manner of humidification is the use of a humidification tent: a polyethylene tent is built above a water-filled vessel of the adequately dimensioned ground area and the object is placed on a grid above the water so that the vapour may permeate it. The extent of vaporization can be increased and partly regulated by leading cold vapour produced by an ultrasound humidifier into the tent. The advantage is that the tent can be opened and - when the air in the external space is not too dry - the object can be reshaped amidst humidified conditions. The disadvantage is that it is very hard to set exact relative humidity content steadily and it requires frequent checks since it depends on the surrounding temperature. Besides, the measuring instruments at our disposal show the often sudden humidity change at a delay, and the electricity that the ultrasound humidifier needs cannot be provided, nor can the measuring data be controlled, after working hours. Another way to humidification is to add some salt to the water providing in theory 90-100% humidity above the water surface to decrease the amount of vaporization. The vaporization of the saturated solutions of