Why is there a glass of water in some cultural relic display cabinets
Shenzhen display cabinet manufacturers tell you that the most fear is drying. A lot of wood and bamboo will be deformed in the dry environment.
In the process of wood drying, when the moisture content of any part of the wood falls below the fiber saturation point, normal drying shrinkage will occur. Because of the uneven distribution of moisture content in the cross-section and the anisotropy in structure, the internal stress between them occurs, which makes the wood deform and strain.
For example, the old wood carvings, old furniture and old wooden buildings that we see now all have cracks. This is why rosewood, such as red sandalwood and Huanghua pear, have been sought after since ancient times. In the words of carpenters, this kind of high-grade hardwood is "small in temperament", with delicate wood and small stress. The environmental changes such as dry, wet, cold and hot have little impact on it. The general bamboo and wood carving, a long time, but in the face of dry and cold weather, or encounter the wind, it is easy to burst a crack. Including ivory, the so-called "old teeth must have a smile", that is to say, as the year goes on, cracks will inevitably occur due to stress.
The dry environment has a bad impact on cultural relics, and the extreme situation is the lacquerware in water.
Lacquerware is actually a layer of lacquer on the outside of bamboo, wood and castor. Many wooden bodies of lacquerware in the dry pit are now completely rotten, and only traces of lacquer skin can be removed when unearthed. Therefore, the complete ancient lacquerware that we see at present is generally produced in the water pit. In the past, when modern technology had not been used in the field of cultural relics protection, the dehydration treatment of saturated lacquerware was a big problem in the field of cultural relics protection. When Ma Weidu talked about miscellaneous matters in the forum of 100 schools, he once discussed this issue Lacquer ware unearthed before Han Dynasty can be divided into dry pit and water pit.
The dry pit is excavated from the dry place, while the water pit is excavated from the underwater or the place with water. It is difficult to distinguish the authenticity of lacquerware unearthed in gankeng. I have seen the lacquer bowls unearthed in gankeng with dim luster. It is necessary to dehydrate the lacquerware unearthed from the water pit. If it can't be dehydrated well, it will shrink into a small ball and cannot be restored to its original state.