By reading this article, you have already shown the first qualification to proceed further: a basic interest in wood and how wood is used.
Millions of people share this interest. We all benefit to some degree from its use. From the raw material used for paper to houses and furniture, wood is all around us.
Technology has advanced and developed metals, alloys, synthetic resins and plastics. Wood in its natural form, though, has been a part of our lives for thousands of years and will remain that way.
In every culture and country, wood has a universal and appealing presence. As a material for construction it’s invaluable. It’s also extremely strong for its weight. Wood can be used to create complex structures at relatively low cost.
Properly treated, timber (also known as lumber) will last for years. Examine your surroundings and this will be confirmed.
Centuries of woodworking tradition have refined the techniques and tools we currently use. Many styles and uses have evolved.
Wood is a sustainable resource. This is more important than ever with the worsening state of the environment. Well-managed woodlands can produce an inexhaustible supply of material. They are also vital to a balanced environment.
Think about asking modern tech workers to invent a synthetic material with as many qualities as wood. Then consider asking them to add more properties… to make it feel warm and alive to the touch.
The widespread interest in woodworking is in part due to the fact that wood is an organic material. As an organic material, wood is unpredictable and constantly varying from species to species. This is due to a variety of factors from climactic conditions to milling methods.
The entire process, from felling and conversion to final application of protective finishes must take this variety into account. As a cellulose and hygroscopic material, wood constantly takes up and gives off moisture in response to its surroundings.
These unpredictable qualities present a great challenge to craftsmen. Woodworkers must view wood in two ways. A scientific look is necessary to understand and control these variations. Regarding artistically helps to expose and enhance the natural beauty hidden within the cellular structure. When you think of it in this way, it’s perhaps no surprise that cabinetmakers are held in such high regard.
The Raw Material
Trees are arguably the most prominent members of the plant kingdom. They have been around for millions of years. They form a fundamental part of the natural biological cycle that keeps our planet alive and well.
Like all plants, trees depend on a process called photosynthesis. They harness the sun’s energy, combine it with carbon dioxide from the air and produce the nutrients they need to grow. In return, oxygen is emitted to the atmosphere. Vast quantities of water evaporate from the leaves.
The most useful and important part of the tree is the trunk. This is also called a bole.
The trunk has three pivotal roles:
- It conducts water or sap from the roots
- It supports the weight of the tree
- It stores the nutrients produced in the leaves to lay down new growth
Different parts of the tree trunk are adapted to each function. All, though use the same basic building blocks: the cells. These cells have walls made of cellulose which is the raw material of wood.
When pulped and processed, cellulose can be made into paper. When it is left intact it provides one of the most versatile construction materials available.
Softwoods and hardwoods
Depending on the species and conditions of growth, wood has a wide range of characteristics in varying degrees:
When you are woodworking, understanding these qualities will help you select the best material for the job.
One of the first choices you will encounter is perhaps not as straightforward as it would seem…
Softwood or hardwood?
Trees are divided into two botanical groups:
- Gymnosperms (conifers)
- Angiosperms (broadleaves)
These groups are popularly and respectively known as softwoods and hardwoods. This term, however, can be misleading.
Some so-called softwoods from coniferous trees (such as yew and pitch pine) are considerably harder than certain tropical hardwoods (such as the lightest wood, balsa).
The strength of timber is determined by its density. This can vary within the same species according to its country of origin and rate of growth.
Conifers are concentrated primarily in the cooler regions of the world in both the northern and southern hemispheres.
Tropical hardwoods, as the name implies, are found in the equatorial belt.
Temperate hardwoods occupy the middle zone. This third group is of special interest to woodworkers. Great variation can be found in the color, distinctive grain figure and working properties of this group. Commercial supplies from sustainable sources are readily available at reasonable cost.
Whatever group timber belongs to, the woodworker will want to know about its workability… How it behaves when worked by hand or machine tools like a miter saw, the quality of the grain, how it takes to different adhesives and finishes.
For most practical purposes, the more commonly available commercial softwoods all have certain similar features. This handy table shows you these at a glance so you can check out the advantages and disadvantages of each type of wood…
|Low density: 400-600kg/cu m
|High density: up to 1000kg/cu m|
|Great strength, light weight
|Heavier and sometimes brittle|
|Less durable in wet or damp
|More suitable for exterior use|
|Less resistance to insect attack
|More resistant to decay and rot|
|Generally pale in color
|Light to very dark|
|Usually more open-grained
|Close-grained and harder to work|
|Tendency to shrink or swell
|Low cost, readily available
|More expensive, harder to obtain|
We will continue looking at different aspects of wood with our next article focusing on the structure of the material.
As a discriminating woodworker, you will know that the real pleasure of woodworking comes from exploring the potential of each species and using it to its best advantage.
The knowledge and careful selection of raw material is one of the most important steps you can take in developing a true feel for your craft.