What was and what will be.
 

Khai Dinh goes his own way — traditional
and modern elements in Vietnamese architecture

Architecture was a major passion of Khai Dinh, the twelfth and penultimate emperor of the Nguyen dynasty. During his brief 8-year reign (1917-25), several large and small palaces were built for the imperial family, only the first of which has survived: An Dinh Palace, commissioned immediately after his coronation. His second lasting monument is his mausoleum, the most time-consuming of his projects, completed only six years after his death.

French palaces inspired Khai Dinh. He considered traditional Vietnamese architecture passé. This 'Emperor by the grace of France'' cherished a dream of impressive, splendiferous architecture that would stand out from anything his forefathers had built.

The An Dinh Palace with its extensive grounds was his first step towards making this dream come true.

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The big mix — old and new construction materials

The most valuable and common construction material traditionally used in Vietnam is wood, followed by bricks, clay roof-tiles, various mortars and stone. Such materials can withstand the country's climatic conditions fairly well. Hué is tropically humid all year round (80-99 %) and sees heavier rainfall than the rest of Vietnam (annual average: 3031 mm), so decay occurs relatively quickly.

Elaborate decorative elements in Vietnamese architecture comprise faience, mosaics of porcelain and glass, mortar sculptures and reliefs, enamel screens, wood-carvings, gildings and natural lacquers, all of which have been adapted to these extreme local conditions.

By contrast, Khai Dinh's modern buildings were built of brick and have steel and iron roof girders. Cement was added to traditional mortars and plaster. Wood was used only for windows, doors, attic floors and decorative carvings. Khai Dinh largely retained traditional decorative methods yet European styles influenced his choice of motifs. The fusion of eastern and western architecture began as early as 1845 but only under Khai Dinh did it develop as an impressive, independent style.

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Baroque style — An Dinh Palace leads the way

An Dinh Palace is characterised by the fusion of interior and exterior space common to the French Baroque palatial style. Double doors and interior apertures interlinked all central rooms in the original, symmetrically articulated, 2-storey building whilst further doors and windows in all peripheral rooms on the ground floor gave onto large terraces. This was modern, open architecture, directly oriented to the surrounding gardens. Numerous windows glazed with new-fangled, structured glass assured the rooms an intimate yet airy ambience, even when closed during inclement weather.

Every wall and ceiling in the Palace was elaborately painted and enhanced by stucco or sculpted cornices. So-called 'conservatory-style' decorative paintings — with floral motifs, garlands of butterflies and flowers, and trompe l'oeil effects on the door and window frames — accentuate the desired fusion of interior and exterior space. Decorative paintings on the walls of the centrally situated reception rooms and private quarters are intended to evoke the illusion either of traditional paintings on silk canvases (in 3 rooms on the ground floor) or patterned wallpaper (in 3 rooms on the 1st floor). All doors and window apertures in the ground floor rooms have elaborately carved gilt frames. Panelling is a further decorative feature. The reflected ceiling plans are decorated with floral motives and trompe l'oeil depictions of painted woodcarvings.

Six large wall paintings depicting the mausoleums of the six most significant emperors of the Nguyen dynasty decorate the most important reception room at the heart of the Palace, the main salon. These paintings have a central perspective (instead of the traditional, 'eastern' parallel perspective) and are held to number amongst the earliest examples in Vietnam of this 'western' style of representation, which became known in Vietnam only at the turn of the 20^th century.

The floors of the Palace are decorated with ornamental, polychromous, stoneware tiles. The technology originated in France yet the tiles were probably manufactured in Vietnam.

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Original materials — the ingredients

The plastered brick facade of the Palace is richly decorated with stucco and was originally finished in a lime-based, ochre-coloured wash.

The walls and ceilings, cornices and panelling in its interior all consist of an extremely stable plaster. Initial tests revealed that it is a lime-based plaster, containing a small proportion of cement and greater proportions of proteins. It possibly also contains traditional ingredients such as sugar cane and resins. This combination of lime, cement and, probably, additional traditional binding agents assures an extremely smooth plaster finish.

The 'ground' (base layer) beneath all painted surfaces consists of chalk, white lead and a protein size binding agent.

Wall paintings in the main salons — the ground floor reception rooms — were executed in resin-based paints and then varnished. Natural resin was probably extracted from the 'lacquer tree' (vietn: Cay so´n, lat: Rhus Succedanea), the milky-white sap of which has long been tapped in Asia and subjected to long, complex manual processes to produce lacquers of various colours and quality. It is unlikely that the resin was used in unadulterated form for painting, as its consistency is quite rubbery. A mix of resin and oil or resin and wax is more common. Specific tests ruled out the use of oil in this case, however, so the use of wax can be assumed.

All the remaining wall and ceiling paintings were executed in protein size-based paint and then varnished. This technique is uncommon so there was reason to suppose that varnish had been applied at a later date to freshen up the painting, which our tests subsequently ruled out, however.

This brief excursion into scientific detail illustrates how difficult it can be to identify original materials. Here we find combinations that were neither usual in Europe at the time nor rooted in Vietnamese tradition. For the paintings, as for the Palace architecture, various materials were combined and applied in innovative ways.

Whilst tests continue to be made, experience has shown that, with regard to organic substances, even the most advanced methods of scientific analysis have their limits.

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Materials used in later phases — no longer quite so fine

Around 1920 a 3^rd storey and four additional rooms on its northern side were added to the original building, using the same methods and materials as in the initial construction phase. Certain improvements and the redesign of individual features were also possibly undertaken at this date, or at some time around 1945. The decorative paintings produced at this time contain a protein size binder and were not varnished. Some of them were executed with considerably less talent than the earlier paintings in the Palace.

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A hard fact to face — monochrome monotony

When the state began to use the Palace in 1975, all wall paintings except those in the main salon were painted over. Ceiling paintings were retained in the main salon, the two adjoining salons and the two stairwells. Paintings executed in resin-based paints were first painted over with a synthetic resin-based paint; paintings executed in protein size-based paints were painted over with a lime-wash, protein size-based paints and synthetic resin-based dispersion paints. Ceiling paintings on the 2nd floor were thinly coated in cement in order to prevent water damage. Door and window frames and panelling, all originally painted with a traditional reddish-brown natural resin-based paint to resemble fine wood grain, were painted over with a synthetic resin-based paint.

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The damage — non-stop drip drop

It was established that existent damage was essentially due to:

• the use of materials unsuited to local climatic conditions
• both the permanently high degree of humidity, and condensation caused by extreme seasonal changes in temperature
• structural damage caused by war and/or inadequate maintenance (leaking roof, defective or blocked water pipes and guttering, broken glazing in doors and windows)
• ill-fitting doors and windows that, especially in windy weather, fail to keep out rain
• chemical reactions in original materials and encrusted salts, both caused by humidity
• later coats of paint
• usual wear and tear and/or inappropriate treatment

The main types of damage comprised:

• deterioration of protein size-based paintings due to swollen grounds and the disintegration of binding agents
• partial instability or even total loss of resin-based paintings due to swollen grounds
• hazy areas of paintings caused by chemical reactions in plaster and encrusted salts
• cracks in plaster, water stains and discolouration, due to partially corroded iron ceiling girders.
• craquelé formation: resin varnish grows dull, cracks, turns brown and damages paintings
• soot from additional kitchens (improvised presumably when homeless people took refuge in the Palace in 1975)

Evidently, the main cause of damage is the effect of water in its various guises (humidity, condensation, rain, etc.) on original materials, and the chemical reactions thus triggered.

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Restoration concept — like a phoenix from the flames…

Beneath the later coats of monochrome paint the original decorative paintings were in various states of repair yet the conservation/restoration of all of them seemed feasible. It was therefore planned to expose them and carry out conservation/restoration in order to recreate the splendour the Palace had originally, in its days as an imperial residence.
Structural measures to underpin the long-term success of this venture — first and foremost the repair of the roof and other sources of unwelcome water — were undertaken by the HMCC in parallel with GCREP's work on the interior decorations.

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Measures accomplished — in countless small steps

Due to the instability and toxicity (white lead content) of lime-based grounds on smooth plaster, the exposure of painted-over paintings was an extremely delicate process. Scalpels are used for dry exposure whilst a MEK (2-butanone) solution is applied to loosen synthetic resin-based paints. All paintings except those on the ceiling had been varnished. A white spirit/ketone solution was applied to thin the discoloured, dull varnish. On the edges of damaged areas of paintings executed in resin-based paints, dissolved resin simultaneously soaks through size-bound paint layers into the lime-based plaster base and stabilises it. A solution of white spirit and non-ionic cleanser (Vulpex liquid soap) is used to remove haze and encrusted dirt from paintings. Further stabilisation of the ground and paint layers proved unnecessary for resin-based paintings whilst many areas of protein size-based paintings needed an application of Klucel E stabilised by Paraloid B72.
Despite the high level of humidity and the fact that it had been repeatedly covered in paint, cement or varnish, plaster on the walls and ceilings was astonishingly stable. A lime-based mortar containing a small proportion of cement was used to restore damaged areas. Fillers and smooth grounds were manufactured from calcite and acrylic paints.

Where corroded iron girders had caused cracks and gaps in plaster, loose painted plaster fragments were removed and ground down before being reinstalled following renovation of the girders.

Retouching of paintings was executed in acrylic and oil paints. Those paintings that had originally been varnished were given a final dammar glaze.

Monitoring temperature and humidity levels, pre-testing materials, and experience gained in the initial project phase all clearly demonstrated that materials must be able to withstand tropical conditions. Fungal spores, accelerated deterioration of binding agents and discolouration pose the greatest menace. Materials containing natural, organic components therefore prove unsuitable whilst European acrylic dispersion products are too unstable.

The acrylic paints used, especially developed for Vietnam by Nippon Paint in Singapore, contain pure acrylate, lime, stable pigments and a fungicide.
The limited spectrum of primary materials that have proved most effective since work began in 2003 comprises Klucel E (with additional Preventol ON), Paraloid B 72, Ledan, Vulpex, Mixol dispersion paints, artists' oil and acrylic paints and dammar resin.

Due to transport costs and import constraints - as well as to our commitment to developing sustainable, locally feasible methods as part of the training programme - testing and using traditional and modern Vietnamese products for conservation/restoration purposes has also been an important aspect of our work. The range of products available for work in this complex, specialised field is still very limited, however, as the conservation of historical substance is a relatively new concern of heritage preservation in Vietnam.

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The future: lofty aims for a precious site

Conservation/restoration of the Palace interior will probably be concluded at the end of 2008. Work on the grounds of the Palace is still underway.

An imminent highlight is the first public presentation of restored sections of the Palace and an exhibition about this project, which will take place as part of the Hué Cultural Festival in June 2008.

The Palace will be maintained in the future both as a museum and as a venue for cultural events.

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