How to judge the quality of wood with basic common sense? Wood is closely related to our lives. How to identify the quality of wood is what we all need to know. Today I will introduce in detail the basic common sense of how to judge the quality of wood?
Price list of various logs
1. Common sense to identify the quality of wood
First of all, we must have a basic judgment on the quality of wood, which is the basis for judging the value of wood.
For this issue, there are both professional identification standards and empirical judgment standards, and the two standards cannot completely replace each other. Under normal circumstances, for most people, professional identification is not available, and today's wood identification in my country can only determine the genus, which basically has no practical significance for identifying wood, and empirical judgment is often more reliable. operability.
Are empirical judgments reliable? There is no doubt about this! Even empirical judgments can make up for the obvious deficiencies of professional appraisals, making them more reliable in real life. Because empirical judgment has both the accumulation of experience passed down through generations, and the regular summary of scientific identification. Therefore, the empirical criteria for judging the quality of wood is essentially the common sense of wood identification that has been tempered. Here are some of the most basic common sense as follows:
First, the general classification of wood.
Wood is roughly classified according to its use, from high to low, it is divided into high-grade handicraft wood, high-grade furniture wood, high-quality furniture wood, ordinary medium furniture wood, medium and low furniture wood, and firewood. In different regions, there can be crossover between two adjacent grades of wood. For example, some woods that are regarded as firewood in southern forest areas are regarded as mid-range furniture wood in northern areas; mahogany, which is regarded as top-quality wood in Europe, can only be regarded as medium furniture wood and decorative wood in China.
Second, the presence or absence of core wood is an important watershed for the quality of wood.
Generally speaking, tree species that do not grow core wood, no matter how good they are, can only be used as medium and low-grade furniture wood at best. For example, fir, cypress, elm, most pine, and many species in the genus Lauraceae, do not have a long core. Although some woods without long cores are also very good, most of the woods without long cores can only be used as firewood or raw materials for making synthetic wood; and all high-grade woods and high-quality woods are made of long-cored wood. It comes from the wood of the tree, and its genuine product only refers to its core material, and does not include the sapwood of the tree species, nor does it include the tender material of the tree species that has not yet formed the core material.
Third, the hardness and specific gravity of the wood.
There is no doubt that the harder the wood, the better. Of course, if the wood has both high hardness and high flexibility, it will be better, such as teak, Dianrunnan, oak, walnut, etc. The best of them is huanghuali. The technical term for the specific gravity of wood is called air-dry density, which refers to the number of grams per cubic centimeter (g/cm3) when the moisture content of wood is about 12%. Of course, the higher this indicator is, the better. That is to say, what we often say is that the wood that feels heavy in the hand is mostly good wood; on the contrary, if it is light in the hand, the material is not much better. When the air-dry density is greater than or equal to 1, the wood is called submerged material. In submerged materials, it is difficult to find wood with poor quality.
Fourth, the color difference between the core material and the sapwood.
This is an easy and effective way to identify the quality of wood: the greater the color difference between the core and the sapwood, the better the core material. Almost all hardwoods have a dark core and a light sapwood. Some pine will also have a long core, but the color difference between the core and the sapwood is very small, so pine is rarely a high-quality wood. Among the nearly 200 species of nanmu, most of the tree species require long core wood, and those tree species called golden nanmu are the nanmu with long core wood and the color difference between the core material and the sapwood is larger, and the color difference is the largest. A kind of nanmu is Dianrunnan. Of course, there are also a few trees that do not grow heartwood that are good, which is a special case.
Fifth, the basic characteristics of advanced wood.
High-grade wood must have more than 4 of the following 6 indicators: (A) aroma; (B) excellent material; (C) beautiful wood grain; (D) beautiful or unique wood color; (E) rich in oil, Wear-resistant, corrosion-resistant and insect-resistant; (F) genuine core material of this tree species. Among the 33 species of mahogany listed in the national standard of "Redwood", many species of wood can meet all the above 6 indicators, and the rest can also achieve 4-5 indicators.
Sixth, whether the core material is naturally grown to old.
This is a seemingly unimportant factor that is actually very important. All trees that want to grow core must reach a certain age of growth, and their light-colored sapwood will begin to gradually transform into core. This transformation process will last for many years, and it is also the process of the natural growth of the core material to the old, and the color of the core material will gradually become darker. Generally, the proportion of the core material in the cross-section of the wood exceeds 95% to determine whether the core material grows naturally or not. For white wood, wood that has not yet formed a core material is a tender material. Although it is available, it is not genuine. The sapwood is a waste that should be removed when using it. Tender materials that have not formed a core material, but are still underage materials; those with a core material proportion of 80% are basically usable wood; those with a core material proportion of 90% are normally usable wood; those with a core material proportion of 95% or more , that is, high-quality wood that grows naturally to old age; the so-called "old material" that is stored or used for many years from tender materials is as different as the wood that grows naturally to old age. For hardwoods such as red sandalwood, fragrant branch wood, and rosewood, 80% is often close to the limit of the core material ratio.
Seventh, the relationship between growth area and material.
The wood of the same species grows on the barren mountains, and its material is worse than that of the dam area or hilly area; the wood that grows in the temperate area is generally not as good as the material that grows in the subtropical or tropics. On a global scale, the quality of wood in cold regions is generally not as good as that in temperate regions, and the quality of wood in temperate regions is generally not as good as that in tropical regions. Almost all of the world's finest woods are produced in the tropics.
The relationship between growing area and material
2. 6 elements for judging the value of high-quality wood
Now, on the question of judging the value of high-quality high-grade wood, a simple judgment standard is given. There are a total of 6 major elements, the following is one by one -
First, the aroma.
The first characteristic of high-grade wood is that it has a natural special aroma. Such as Indian Laoshan sandalwood, huanghuali, red sandalwood, golden nanmu and so on. Without this element, no matter how good the material is, it cannot reach the top level. The typical representative is old mahogany.
Second, wood grain.
High-grade wood must have beautiful wood grains, such as huanghuali, red sandalwood, old mahogany, red shadow wood, and golden nanmu root materials.
Third, the material.
This is a very important condition when making furniture and handicrafts. The finer the material and the tighter the structure (higher air-dry density), the better.
Fourth, material color.
This refers to the natural tone and colour of the wood plank after planing. Red sandalwood, huanghuali, old mahogany, etc. are all famous for their excellent color. Among the better two kinds of golden silk nanmu, Zhennan is more popular than Dianrunnan simply because the material color tone is brighter and the material color is relatively more uniform. Although Dianrunnan has better material, more intense and lasting aroma, and the most obvious characteristics of golden nanmu, it cannot change most people's preference for material color.
Fifth, oily.
Of course, the heavier the oiliness of the wood, the better. The oiliness of wood is an important indicator of the superiority of the material. The heavier the oiliness, the more intense and lasting its aroma is, and the stronger the wood’s resistance to insects and decay. Hainan huanghua pears are divided into bran pears and oil pears based on their oiliness, and the value of oil pears is more than double that of bran pears.
Sixth, material diameter.
This refers to the size of the specific material diameter (sheet width), the bigger the better. If the diameter of a specific sheet of material exceeds the upper limit of scientific records, it is a rare treasure of heaven and earth. For example, the species of Dalbergia cochinensis (Sorrelwood) has a maximum diameter of 60 cm. If you find that the board width of this material exceeds 80 cm or even wider, it is super lucky, because you meet the sky. Treasure of material. Of course, there is absolutely no reason for this kind of material to be priced in terms of tons or cubes, but only in terms of pieces (pieces, roots).