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 Examinations and Tests | |
Date/Period of Implementation: 2000-10-00 To 2000-12-00 | |
Description:
Tests to determine appropriate materials for readhering the lifting ground layers and to consolidate the flaking paint were already made for the conservation of the lower coffin box. Properties such as penetration, ease of application, adhesion to substrate, long-term effects of aging and alteration in surface appearance were all considered in these tests and can be found in the `Conservation Treatment-Report` (1).
The following examination deals with the investigation of the dark yellow to brown coating. Various techniques were employed including microscopic and ultra-violet light examination and chemical tests.
On close inspection the coating has an irregular surface. The thin areas are transparent and the thick areas are glossy, dark yellow to brown. The coating was applied with a small brush mostly in the white hyroglyph areas. Microscopic examination reveals that the coating is craquelured, sometimes cracked and very brittle with some loose spallings, flaking and small voids. Some areas are blanched, caused by a blooming of the coating surface.
(Images Folder: canterb_mummy_fig_09.jpg)
Through the ultra-violet light examination, the fluorescence of the coating is a bright yellow. This examination confirms that the coating is primarily on the white hyroglyph areas, with a thin application in some coloured areas. No coating was applied to both sides of the head, the face, the feet (ankles including and bottom) and the right side of the pelvis.
Tests were conducted to determine the possibility of removing the discoloured coating. Observations while taking the sample with a scalpel blade under the microscope are irregular delamination from the paint layer, revealing a porous surface, which is very easy to scrape and crush into glossy splinters. There is a smell of conifer resin when the coating is crushed between the fingers.
Under the microscope, the solubility of the coat was last tested, by dropping deionised water, ammonium hydroxide, acetone and ethanol on a small sample. The sample was insoluble in water, slightly soluble in ammonium hydroxide and soluble in acetone and ethanol (investigation: canterb_mummy_inv) . For further examinations of the coating, a sample has been taken and kept in a zip-lock plastic bag.
A small test was carried out on the surface of the coffin lid using acetone and ethanol which both removed the coating successfully.
(1) (Literature Titles/Sources: Ng, Amy 1998) pp 7-11 |
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Removing of the coat | |
Date/Period of Implementation: 2000-10-00 To 2000-12-00 | |
Description:
Following the further treatment recommended by Amy Ng (1), contract objects conservator, the yellowi-brown coating was tested and found to be reversible. The decision to remove the coating was made for two reasons.
o The coating is unlikely to be original. Before resin can be applied as a thin coating it must be in a liquid state, however resin can only be dissolved in a turpentine or pure alcohol which was not discovered until relatively recently. It assumed that the coating was originally colourless and transparent but the carelessness with which it was applied is very dissimilar to the original paint application. It is remarkable as well, that the coating was carried out only on the coffin lid. The coating appears nto be a previous treatment, following excavation, to protect the water soluble surface before sending the coffin overseas.
(Images Folder: canterb_mummy_fig_10.jpg)
o From a conservation point of view, the coating is so brittle and strong that it is actively delaminating and removing portions of the painted surface.
With the help of a magnifying glass the coating was removed from the surface using ethanol on a cotton swab. The penetration of the coating material into the gesso and paint layer left a slight yellow stain that cannot savely be removed. However,the overall result has dramatically improved the surface appearance and revealed the full hyroglyphic text.
(Images Folder: canterb_mummy_fig_11.jpg)
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(1) (Literature Titles/Sources: Ng, Amy 1998) p 15 |
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Readhering lifting areas and consolidation of flaking paint | |
Date/Period of Implementation: 2000-10-00 To 2000-12-00 | |
Description:
Following the previous examination, assessment, stabilisation and consolidation carried out on the lower coffin box, the same treatments for the coffin lid exterior were adopted. A different treatment had to be found only for parts of the interior. Properties such as penetration, ease of application, adhesion to substrate, long term effects of ageing and alteration in surface appearance were all considered in the testing of the materials (1). Fragile paint in danger of being lost on the coffin exterior was consolidated using 3% Klucel® G in ethanol. The area was first wetted out with ethanol, followed by painting the consolidant on top of the painted layer. Three to four applications were given, without imparting any gloss or changing the appearance of the surface.
(Images Folder: canterb_mummy_fig_20.jpg)
The lifting areas were readhered by using a Paraloid® B-72 adhesive film (30% w/v acetone) as a heat-set material. The flexible film was inserted between lifting areas on the box exterior and the edges of the interior. To protect the painted layer, silicone release paper was laid over and a heated spatula used to soften the Paraloid® film and set the adhesive. The technique is reversible, has no effects on the appearance of the painted layer and was not time-consuming.
(Images Folder: canterb_mummy_fig_21.jpg)
(Images Folder: canterb_mummy_fig_22.jpg)
The interior of the coffin lid has areas of loss with lifting edges and tenting areas caused by compression forces of the wooden substrate. To protect the gesso layer in case of further movement, damaged areas were completely covered with Japanese paper and adhered with 5% Klucel® G in ethanol. This treatment can easily be removed with ethanol, without damaging the surface. The areas were not disguised as the interior is not decorated and will not feature on exhibition.
Loose edges along the inside of the feet section were adhered with Paraloid®.
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(1) (Literature Titles/Sources: Ng, Amy 1998) p 13
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