24 February 2006
Reason for treatment
Conserve and remount
I. Condition of Paint Layer [see graphic documentation and 1830 drawings before mounting]:
Paint samples analysed by Janet Ambers( see reports)
* Staining in the surrounding edge (ca 6cm) is patchy, not regular (differently than EA 37983).
* Extensive loss in background white layer in the surrounding edge, and of some other colours too (of which reds seems most damaged).
Some areas show numerous small round losses, not unlike the pattern related to salts.
Extensive loss is also noticed in the areas of green frit and Egyptian blue: this seemed genereally linked to the painting technique. A lot of areas painted with these pigments show an application in thick impastoes - thus requiring a lot of binding medium, which would have tended to shrink back (this could have fragilised the area, possibly causing a loss over time; another possibility is the loss of binding power over ageing).
* Abrasion found in a surrounding edge (extending up to ca 15-20 cm within). Several abraded areas appear in the same zone as salt pustules and/or salt pustules losses; these could be the result of brushing of salts from a friable polychromy.
* Salt pustules (crystallised just below the paint layer) to be found in the surrounding edge again; these are found in association with losses. Their pattern, as well as that of the small losses, is not unlike that found in association with a sulphation problem.
* Flaking/microflaking and powdering was noted in many areas, mostly in the surrounding edge. Flaking also appears in association with a residual yellowish coating.
* Past treatment have darkened the edges of lacunae in some black areas.
*Impact damage: Areas of impact damage were filled with plaster of paris, probably at the time of mounting as photos of this painting have always been shown with these.The damage is very low the to the ground and may have caused by a wandering child. Most of the impact damage is similar in diameter suggesting it might come from the same tool and classically it is rounded in form with the paint pushed back from the surface into the depression. The cracked area around the interior of the paint has been lost (see diagrams for locations)
extensive areas of cracks have also been filled. An area at the base of the painting has been filled with beeswax, this is a later restoration probably to remedy loose areas after the paintings were returned to the BM from wales after WW2.
II. Condition of Plaster Layer:
* Delamination between the gypsum intonaco and the mud-plaster arriccio is a serious problem, especially in association of the extensive networks of cracks.
Some of the cracks have clear breaks, which could indicate they may well have formed recently.
Some fills in the cracks have shrunk back and deformed from the edges.
* Areas along the top and bottom edge of the fragment show a deformation and tenting pattern in the plaster (associated with thin parallel hairline cracks), which is clearly the result of compression forces (this fragment has remained a long time vertical, while the weight of the plaster of Paris must have weakened it increasingly). In some instances, the edge has even broken up in small fragments.
The object was thoroughly examined under a microscope. Observations on ancient painterly techniques, past treatments and present treatments were recorded individually as technical information record on hard copy (see envelope for detailed information). A photoshop file detailing the objects condition, observations on painterly technique, past and most current treatment is also available on memory stick.
The object was lightly dry cleaned with low suction vaccuum cleaner.
The paint flakes were consolidated using Primal B60A (acrylic), introduced by brush following the flooding of the surface with White Spirit (composition variable - petroleum distillate) which was applied by pipette. The White spirit has been found to help this process by carrying the resin further afield via capillary action, thereby consolidating a larger area. Excess resin is removed with Acetone (propan-1-one/dimethyl ketone), if the resin has set it can be pushed off the surface with a brush wet with acetone and picked up.
Powdery areas of intonacco were consolidated with several applications of 1.5% Paraloid B72 (ethyl methacrylate copolymer) in Acetone (propan-1-one/dimethyl ketone)/Industrial methylated spirits (ethanol,methanol)(1:1). Plaster of paris which was filling the gap left by impact damage was gently soften with small swabs of deionised water and then removed mechanically to expose the underlying arriccio. Fragile areas of arricio were consolidated with 20% Primal B60A (acrylic) sprayed on over White Spirit (composition variable - petroleum distillate) used as wetting agent.
The old plaster mount of the object was removed mechanically with a minidrill.. Araldite CW2215 (foamed epoxy) was used for casting a new mount. A paste of microcell glass balloons in 20% w/v Paraloid B72 (ethyl methacrylate copolymer) in Acetone (propan-1-one/dimethyl ketone)/Industrial methylated spirits (ethanol,methanol)(1:1) was applied to the arricio underside and edge to act as an interfacee between it and the new foaming epoxy resin mount enabling future reversibility. The new epoxy resin mount collar was set back from the edge of the arricio by approximately 5mm.