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THE EXPERIENCE OF THE CONSERVATION OF THE PLASTER SCULPTURE FROM THE COLLECTION OF THE STATE TRETIAKOV GALLERY

VASSILIEVA, O.A. The State Tretiakov Gallery, Moscow, Russian Federation

For a number of years The State Tretiakov Gallery was closed because of the long major reconstruction. During that period the conservators of the Gallery had the possibility not only to prepare exhibits for a new exhibition but also to pay attention to the art works of plaster which were always available in the storerooms of the museum. Plaster sculptures, that will be mentioned further, were conserved by the author of this review during the period of 1983-1995.

The plaster is mainly used in sculptures as a material for casting an intermediate draft model to work on later. The property of plaster to expand a little while setting and hence filling the mould entirely makes it irreplaceable in the reflection of all the nuances of the author's surface including thin modellings. In some cases sculptors corrected and finished off the work of art at that intermediate stage before moving it up into the final material (stone, metal, terracota). In the collection of The State Tretiakov Gallery there are several sculptures by N.A.Andreiev where the author had completed the part of the relief above the plaster with plasticine f'The Portrait of KS.Stanislavsky", "The Girl Listening to a Shell"). Such exhibits have an especial value for us, since they demonstrate the Evolution of the realization of the artist's intention who had gradually got the desired result. In those cases when the plaster models had already been used for transferring them into bronze or stone, they are often the only originals which retained the author's intention and genuine relief in full, because in bronze casts and stone, due to the peculiarity of the technology, there are distortions: overall dimensions change, thin modellings of the mould are not distinctly visible. It can be easily seen by comparing the plaster models with bronze casts of the busts by F.1.Shubin "The Portrait of Betsky"" and "The Portrait of Zavadovsky" which are in The State Tretiakov Gallery. Transferred into bronze, the sculptures underwent such deformations so that they ceases to conform to the plaster originals.The author's models, which suffered while the moulds were removed.had to be restoredt splits were masticated. The lubricant was taken off.the thorough touch-type toning of the frayed places was done in order to equalize the general toneu The plaster sculptures acquired a relatively exposition able appearance and were shown in the exhibition of F.1.Shubin 's art works in 1994. Often a work of art had been left by a sculptor in plaster because of the high cost of transferring into the final material or due to some other reasons. Such a sculpture has its own independent meaning. Thus, the plaster sculpture, as a whole, can be singled out into a separate group which has its peculiarities in preservation and conservation Examining the kinds of plaster sculpture damages and methods of their restoring one can pick out the main ones: damages of the construction; damages caused by violation of technology; damages due

to shifting and transporting; spoiling the surface. Damages of the construction - these are big losses depriving the sculpture of its steadiness.that is, damages of the frameworks. For restoring big, shape making, losses the pure analogies were used, i.e. moulded copies of available replicas of the sculpture, photographs taken from various sides before the damages had occured.ln restoring not complicated geometrical shapes (pedestal) the method of inertia was applied, that is, the restoration process logically continued intact sides and planes. In case of the damaged framework the deformations were removed, the original direction

was restored and, where possible, the corrosible bars were removed and replaced by bars made of glass fibre.The glass fibre bars are suitable for the treatment since they are not subject to corrosion, relatively durable, have light colour and are also used in marble sculptures. In the cases where it was impossible to change fixtures completely, the accessible corrosible fragments of the framework were to removed and replaced. The open parts of the corrosible framework were cleaned and impregnated

with a solution preventing the spread of corrosion. By such a method the sculptures "Hands of the Composer A.Skriabin", the sculptor - S.D.Mercurov, and "The Arm", the sculptor A.S.Golubkina were

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conserved. After the treatment of the framework, described above, the restoration of the sculpture "The Arm" by A.S.Golubkina was performed; the surface of the sculpture was generalized and smoothed out with respect to the author's one, since there were no analogies. One can consider as the constructive miscalculation the author's wrong definition of the centre of gravity causing deformation of the framework and depriving the sculpture of its steadiness, as well as too thin walls of the cast, the result of which is the appearance of new losses in thin parts and also cracks in the base due to the overall weight of the sculpture. Thus, in the pair sculpture "The Sons" by P.Trubetskoy they had to restore small dropped out portions of the thin walls of the cast. The including by the author in the plaster paste some foreign materials, such as fabric, cord, hemp etc. can be considered as a violation of the technology. Sometimes in the plaster undissolved pieces of glue are found. These heterogeeous inclusions hamper the pasting together and are dangerous

when the moisture comes inside. The undissolved glue pieces when getting wet can tear the adjacent parts. The above said concerns the works of art by A.S.Golubkina. Because of the particular fragility of the plaster the most possible probability of getting injuries and damages appears while shifting and transporting. These are damages of the construction, but more often - various splits and cracks, tears along the perimeter of the base and on the projecting fragments of the relief, abrasions and scratches. The known method of preparing the restoration paste for restoring with strengthened plaster on the plaster sculpture does not prove its value in the cases when the restoration is not a constructive oneu This is confirmed by the working experiance in the museum workshop of A.S.Golubkina - the branch of the State Tretiakov Gallery - the treatment of the lasten sculpture "The Sitting Man", where the previous conservation repairings, which needed to be removed, had been done by strengthened plaster, and the removal of such insertions resultad in inevitable injuries of the adjacent parts since the durability of the insertions was higher than the durability of the plaster. On the parts where the restoration had been done bv the ordinary not strengthened plaster there were actually no injuries of the original at all. Thus the insertion of the glue solution to the plaster should be justified only by constructive reasons but not only by the observance of the principle of differentiation of restorings, that is quite accessible by the insertion of a pigment to the plaster paste while it is being mixed for preparing the restoration masses. So, in conservation of the plaster bust toned in immitation terracotta (the sculpture by M.l.lvanov "The Portrait of an Unknown Woman",first half of the XIXth century; there was a big loss of plaster at the joint of the bust with the pedestal , the sculpture rotated on the wooden pivot) another method was applied.The aqueous solution of polyvinylacetate dispersion with plaster was inserted into the intermediate space between the bust and pedastal.. Thereafter a layer of not strengthened plaster toned in the mass in imitation terracotta was put on in such a way that, if necassary, it could be easily removed, but at the same time the constructive durability at the joint of the sculpture with the pedestal would be retained. On the same sculpture the refill made of the toned in the mass plaster was executed in the headgeare. On the right side the texture of lace fabric was imitated. It was performed on the plasticine model by the print taken from the author's surface. On the reverse smooth side the inscription-marking about the performed conservation of the fragment was put on. This meets the conservation principles of observing the dif­ferentiation of refills from the original by several indications.

In selecting a method of gluing together a plaster sculpture one had to take into account such factors as the availability of a metal framework, tonings and their colour. The application of aqueous glues can cause stains on the surface of an untoned sculpture and corrosion of the metal frameworka In such cases it is appropriate to apply glues based on organic solvent, gluing together broken parts of a toned plaster sculpture without the corrosible framework is needed, then it is easier to use aqueous solutions of glues. By this method the plaster deathmask of A.A.Alexandrov (the sculptor -S.D.Merkurov), broken into 8 pieces, was restored.

A separate group of damages of the plaster sculpture are superficial damages such as scratches, frays of the toning, splits dents, biological damages by mould fungi, multi-layer tonings of the body, air bubbles.The removal of such damages requires an especially thorough and delicate approach of a

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conservatore. First of all it means the choice of material for masticating cracks, splits, scratches,

bubbles. It should be not onl reversible, i.e. easily removable, but also easy in treatment - adjustment on the spot, grinding, toning. The experience of the treatment of a number of plaster sculptures

showed that for this purpose it is better to use not plaster but gesso-ground which is prepared on the

base of polyvinyl alcohol with chalk as a filler. Such a gesso-ground is convenient in the working process, it can be diluted to the required consistence and gives the needed thickness layer by layer,

by drying out each former layer.Such a method allows to avoid the cracking of the bulk of gesso­ground in drying out. In future this gesso-ground ean be easily processed by hand both by an abrasive

and by watering the upper layer, as well as used for slight leveling a refill with the general level of the

adjacent surface. If necessary such mastications can be easily taken off from the sculpturels surface without leaving behind any traces. A particular attention is paid to the removal of damages of toning

coating of plaster sculptures. Often due to the violation of the technological process of toning by the authors, or due to mechanical effects (for instance, in transportation) - plaster is especially fragile; in violation of the temperature and moisture conditions of keeping there appear peeling, coming off of

the colour layer from the base, crumbling and frays of the toning. During the treatment of such damages a conservator should be very patient and careful in respect of the original colour layer, since

even the slightest negligence (for example, in washing) can cause irreplaceable losses. The removal

of superficial dirtyings from a plaster sculpture often entails a risk of infringement of the author's toning. Most of the toned sculptures have been washed out with "VEPOS" emulsion, the formula

and instruction how to use it are described in detail in the methodical recommendations of A.S.Antonian "Conservation and Restoration of Stone Sculpture", Moscow, 1985. If a plaster sculpture was not toned then one can use a film method of cleaning.elaborated by

A.D.Tropivskaja, as it was done on the relief by N.A. Andreiev "The Portrait of N.V. Gogol". A few yellowish stains which appeared after the compress were taken off by perhydrol.

In stirring the plaster paste air bubbles appear both in the paste and on the surface of the sculpture.In due course some of the closed bubbles which are neer the surface get broken due to mechanical effects, and open, creating various size cavities, which rapidly become dirty and distort the exhibition­

able appearance of the sculptures. Such small cavities were cleaned out, masticatad and treated as

minor refills. Speaking about the toned sculpture it should be explained that the term "toned" means the

generalization of two types of toning. Firstly, this is the author's toning, a picturesque one or the one,

imitating a certain material. Secondly, this is a superficial coating, more often - shellac, that is a consolidating stuff in the moulding process, as well as bringing a specific colour to the sculpturee Such coatings are somatimes uneven ones, with damp patches and stains. In bringing the surface to

the exhibitionable appearance it is necessary to take into account one fact, that is, of which type this

toning is. So, on the "Portrait of K.S. Stanislavsky" (the sculptor - N.A. Andreiav), coated with shellac,

they managed to relax the intensity of the stains and damp patches; and in the treatment of "The Portrait of A. Bely" (the author - A.S.Golubkina) during the exposition they used the slight touch toning of the losses of the picturesque author's surface. Such masters as V.V. Domogatsky, N.A. Andreiev,

A.S.Golubkina, S.T .Konenkov regarded the surface of sculpture like artists, including pictorial devices

into the toning technique. Exactly because of this, entire painting (including the painting by a sprayer)

in conservation have been completely excluded, since the surface loses picturesque features of the

original and becomes dull and faceless. Conservation tonings were performed strictly within the limits

of the losses however small they had been. Only by the method of one-touch toning, gradually,

millimetre after millimetre, it was possible to reconstruct the colourful surface of the sculptures "The

Portrait of Zavadovsky (by F.l.Shubin), " The Portrait of an Unknown Woman"' (by M.l.lvanov) and a number of others. For toning water-soluble paints were used - water-colour with tempera whiting, that

allows to apply the technique of glazing and matches the principle of reversibility in conservation.

During the examination of the funds in 1986 traces of the mould fungus were found on two reliefs of

the memorial of N.V. Gogol (the sculptor - N.A.Andreiev). The analysis showed that the vitality of the

fungus spores was well preserved. The reliefs were placed into an isolation chamber, the surface of

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the reliefs was treatad with catamine solution in the volatile solvent. Such a treatment proved to be an

effective one, since the repeated tests, taken after the procedure, showed that the process of the mould fungi growth was stopped. Generalizing the experience of the practical conservation of plaster sculptures in the State Tretiakov Gallery one can single out the main points:

1. In restoring losses one takes into account the correlation of the hardness of the material of the refills and the original, using not strengthened, loosened, toned in mass plaster. For small rrfills the reversible gesso-ground, which is softer than plaster, is used.

2. In changing a framework the preferance is given to glass fiber bars which are not subject to Korrosion and do not cause coloured stains on the sculpture. In the places where it is not possible to take out a corroding framework, but refilling is needed, there is more expedient to use mastication with organic solvents.

3. The toning of refills and frays is done locally, strictly within the borders of the refill or loss, by slight touches, excluding the usage of an aerograph or a brush.

4. Hydrophobization is obligatory. 5. In gluing together and washing out it is preferably to use compositions not containing water in

order to avoid the appearing of stains and corrosion of the framework. One should especially emphasize the importance of maintaining the proper and stable temperature and moisture conditions in keeping and in halls where the plaster sculpture is exhibited, as well as take preventive measures against possible dirtying. In view of the fact that plaster is a porous mate­rial that easily absorbs moisture, the moisture rate in the room should be 55 - 60% and the temperature 18 - 20°c .

In keeping the sculpture is covered with special cases, made of special saltless thin porous paper giving the sculpture the possibility to "breathe".

The conservation works made it possible to determine the attribution of several sculptures. After the sculpture by M.I. Ivanov "The Portrait of an Unknown Woman" became recognizable they managed to state its identity with the bust from the country-house museum "Arkhangelskoie". As a result of this it became possible to define the person on the portrait.

In the case of the sculpture "The Sitting One" (the author - A.S. Golubkina)it became possible in the process of conservation to change the date of the casting.