Conservation of the MOON GATE in Bower of the Three Friends

Conservation Practice at the CRAFT, the Palace Museum, March to July, 2016

Other Members: Liu Xiaoxiao, Jiang Zhe, Zhao Sarina, the Third Class of the CRAFT and Tsinghua University

Supervisor: Charles Jeffers Moore, Former Chief Conservator in the Preservation Society of Newport County, retired recently.

Historical Background and General Description

The Qianlong Garden was a retirement complex for Emperor Qianlong. Not willing to surpass his grandfather, Emperor Kangxi —who ruled the country for 61 years—Emperor Qianlong vowed to abdicate after 60 years of reign, and ordered construction of the Ningshou Palace, which is so- called the Qianlong Garden. Though he did resign as he promised, the emperor had not lived in the garden meticulously built by his taste. However, the Qianlong Garden still perfectly reflects his artistic and philosophical appetite. It provided the emperor with sumptuous places for recreation, leisure, entertainment, self-cultivation—practice of calligraphy, painting, and poetry—and spiritual practice, as he was a devout Buddhist.

The moon gate of this conservation project is located in Bower of the Three Friends, a small pavilion isolated by rockeries within the third courtyard of the Qianlong Garden. The moon gate is a circular opening in a partition wall in the west room. Bamboo thread marquetry—of a traditional "卐" pattern—covers both side of the wooden structure of the wall, and the opening is framed with carved hardwood in the form of plum and pine tree trunks. Green and white jades were inlaid on the marquetry as leaves and flowers. The jade and the carved wood depict a scene of pine tree, plum blossom and bamboo, the Chinese "Three Friends".

Photodocumentation and Drawings

Craft/Techniques

Research of the Bamboo Thread Marquetry

Bamboo threads

Three type of bamboo threads in different colors and diameters were found.

Cross-section pictures showed the brown bamboo threads were painted because of the pigment particles on the surface, while the black ones might be dyed, since the black color penetrates into the vessels.

Pattern

Reproduction of the unit and integrity pattern of the bamboo thread marquetry

Condition

Structure

There are shrinkage cracks in wood substrate, (marked in red)

Structure is otherwise in good condition

Decorative surface

Thick dust and environmental pollution on surface

Bamboo thread marquetry instability(marked in yellow) and loss(marked in brown)

Attachments

Jade instability(marked in yellow) and loss(marked in green and blue)

Wood instability(marked in yellow) and loss(marked in purple)

Poor replication of replacements for missing jade(marked in green)

Cleaning Test

Dry Cleaning

Both brushing and vacuuming were applied to clean the dust, then cosmetic sponge was used to clean it one more time. They worked very well. After cleaning the surface became shining because the wax coating was revealed. But the abrasion caused by mechanical cleaning may damage the wax layer on the surface.

Aqueous Cleaning

Water (with sponge): Water worked well to clean the dust on the carvings.

Water with surfactant (Triton XL80N): The pH neutral surfactant Triton XL80N at <2% in water works pretty well.

Water with chelator (5% TAC): Some deteriorated wax was wiped off, suggesting that the TAC may be too strong.

Thoughts for Treatment

The Bower of the Three Friends is scheduled to be restored in 2017. The moon gate cannot be move from its original location, due to difficulty for disassembling and transportation. Thus the moon gate should be consolidated at least before the construction of the building, and wrapped and protected during the construction work.

A thorough conservation is necessary to preserve the high value of the moon gate. However, the level of intervention should be further discussed. (Compensation for loss? Rejoin at shrinkage splits? Replacement of poor jade?)

Consolidation should be done before any sort of cleaning.

Future Scope of Work

More examples of bamboo thread marquetry in Chinese art history to be investigated

Research into the coloring methods for the bamboo threads. The threads could have been colored by a variety of methods

Consolidant test

Treatment protocols