1. Redwood shrinks due to thermal expansion and cold contraction, and cracks due to different moisture contents caused by environmental changes.
The moisture content of wood in mahogany is extremely important, which directly affects the later quality and is also the most headache for manufacturers. If the moisture content of mahogany is not enough, it will cause various problems due to the change of weather, resulting in furniture cracking, bursting, shrinking, loose structure, mildew and many other problems. At present, the national standard moisture content is 12% ~ 15%, and the moisture content in dry areas is required to be lower than 15%. In other words, if the furniture produced in the south goes to the north or the furniture produced in the north goes to the south according to the moisture content standard of the origin, the destination will inevitably have problems.
When the south meets the dry weather in the north, it will shrink, which will lead to the cracking of furniture. This kind of cracking phenomenon is ok, and some can be repaired. What I am most afraid of is that the furniture in the north meets the humid weather in the south, and it is easy to crack when it absorbs water. This crack makes the furniture bigger and difficult to repair. Therefore, whether it is produced in the south or the north, its water content standard must be suitable for the balanced water content of the place where it is used.
2. Has the wood been dried to the standard during processing?
This is a man-made factor other than natural factors. Many small and medium-sized manufacturers' drying technology is unqualified. These manufacturers usually adopt pure natural methods. What is a pure natural way? It is through sunlight and air drying that wood is dehydrated by the heat energy generated by the sun. This dried mahogany has a high moisture content, which is easy to cause drying shrinkage or cracking. Skilled manufacturers will naturally not use this "pure natural" method. Generally speaking, skilled manufacturers usually use vacuum drying, microwave drying, microwave drying and so on. The whole process takes about 60 to 90 days. The wood processed by these manufacturers is dried in situ, so the treated wood is not easy to crack. Therefore, only by adopting reasonable drying process and technology can we ensure the production quality and the stability of mahogany furniture made of produced wood, and the probability of cracking problems will be greatly reduced.
3. The quality of mortise and tenon workmanship is also one of the factors affecting cracking.
Good mortise and tenon structure installation must be in place, and there will be no dislocation or competition. Some mortises and tenons are not well made, and the mortise and tenon structure is not installed in place, resulting in some dislocation and competition. After a period of weather changes, temperature and humidity changes lead to thermal expansion and cold contraction, and tenon-mortise structure will be easy to borrow. Who can borrow it? Nature is the force that expands with heat and contracts with cold. Self-adjusting reset, which will make a crackling sound when reset to a proper position. Full tenon is better than half tenon. Half tenon furniture is easy to crack and burst, while full tenon furniture is not easy to crack and burst.
4. Small details on mahogany furniture: shrink seams
This is a matter of detail. Some people will find that there will be a thin seam in many places, generally between 0.3 cm and 0.5 cm in width. This is the traditional process of China classical furniture processing, but it is not a mistake. This kind of joint is also called "contraction joint" and "expansion joint". This joint is not simple, it plays a great role. In ancient times, so many machines were not used to assist drying. In ancient times, wood was dried by sun exposure, so even if the treatment was in place, the moisture content of wood was still a long way from the standard. The problems caused by the weather have arisen. This contraction joint embodies the wisdom of the ancients. The birth of shrinkage joint plays an extremely important role in improving the service life of mahogany furniture. Craftsmen use this technology to prevent the frame or tenon of furniture from cracking in case of thermal expansion and cold contraction caused by weather changes. The width of expansion joint is determined by wood properties and regional climate characteristics. Don't worry if you find that the expansion joints are uneven in size. Most of them will return to their original appearance after seasonal changes.
5. Waxed or painted furniture
Waxing and painting are the last and most important steps before mahogany becomes a finished product. The main raw material for painting is green natural raw lacquer, which has strong adhesion, acid and alkali resistance and corrosion resistance, and can protect mahogany for a long time. Lacquer raw lacquer is common in both north and south, but it is recommended to use it in South China. In the south, due to the humid climate, in order to prevent moisture, many mahogany furniture surfaces are basically coated with a thin layer of raw paint, which is not only luxurious, but also soft in color and not easy to rot. Waxing technology used to be popular in the arid areas of northern China, and there are two kinds of waxing: waxing and waxing. The best thing is waxing, which allows wax to penetrate into wood and has a very good maintenance effect on furniture. Usually a good waxing can last for more than ten years. Waxing is not good enough. Modern waxing only uses cloth to rub wax back and forth on wooden materials several times, and the effect is far less than that of scalding wax, and the wax is worn off in two years. "Lacquer in the south and wax in the north", if the surface effort is not done well, wood is more likely to contact with moisture in the air, and the phenomenon of thermal expansion and cold contraction will naturally become more obvious.
Ordinary cracks are not obvious, even if there are cracks, they are small cracks. Ordinary cracks will not affect the use, and cracks are not terrible. Many mahogany masters can also come to the door for maintenance.