Inventory No. 36524 [1] – Set of Drawing Instruments
Added by Cheryl Wolfe on 24/02/2009
Fig. 1 Condition on receipt.
Fig. 2 Accumulated dirt on the surface of the leather.
Fig. 3 Silver instruments removed before conservation.
Fig. 4 Tarnished silver mounts.
This early 18th Century set of silver drawing instruments is housed in a small, blue leather covered and silver mounted wooden case, with an engraved silver oval one each side of the case. The instruments consist of a folded rule, a curved folded rule, an expandable rule, various drawing ‘pens’ with interchangeable parts and a pair of dividers (see Fig. 3). There are three missing instruments. The lid is hinged and the interior is lined with engraved silver, and closes with a small button clasp. It measures just less than 10cm in length, 6cm width and 2 cm in depth.
The leather on one side of the case is extremely dirty and there are small losses to the leather on the back edge of the case (see Fig. 2). The leather is lifting a little on the front edge, and there’s some scuffing in general to the surface of the leather. The silver mounts are tarnished and have congealed dirt in the crevices; the edges are dented and worn from use, and the interior of the lid is has some wear and tear to the silver (see Fig. 4).
Various cleaning materials were tested on both the leather and the silver prior to conservation, with the following findings:
|
Material |
Cleaning method. |
Results. |
|
Leather |
Dry cleaning with vulcanised rubber sponge |
This does remove some dirt, but it may be picking up blue pigment too. |
|
De-ionised water. |
This picked up the dirt just as well as saliva. Again, without any blue pigmentation. |
|
|
Saliva. |
Picks up the dirt very well. The swabs don’t appear to be picking up and blue particulates. Saliva neutralised with de-ionised water. |
|
|
Silver |
Industrial Methylated Spirit (IMS). |
This removed surface dirt, but left it rather tarnished and the congealed dirt wasn’t removed. |
|
Hagerty Silver Foam ™. |
The silver was swabbed with a small amount of the silver foam on a cotton wool swab. This removed the tarnish very well. The foam was then neutralised with cotton wool swabs dampened with de-ionised water. This process also removed a large quantity of the congealed dirt. |
After these initial cleaning tests it was decided to opt for the de-ionised water for the leather and the silver foam for the silver components. Cotton wool swabs were wetted with de-ionised water and all the excess water squeezed out so that the cotton wool was just left damp. These swabs were then rolled over the surface of the leather and replaced when they had become soiled, repeating the process until a satisfactory level of cleaning had been achieved. Finally, Lifting areas of leather were laid back into place using wheat starch paste (see Fig. 5).
The silver was cleaned, as described in the trial method for Silver Foam. Then, once the area had been swabbed with de-ionised water and dried, a light coat of microcrystalline wax was applied with a cotton wool swab, and then buffed with a soft cloth (see Fig.6).
Fig. 5 The case half cleaned on one side.
Fig. 6 After conservation.