Woodworking: Learning the Basics
Wood is a natural, living material that will last a long time if properly maintained. There are many species of wood and many uses.
Already thousands of years ago man has used wood for weapons (for example stakes), tools and to fuel their homes. At the end of the Palaeolithic period, the presence of arrowheads bears witness to bows, but we must wait until the Neolithic period to better understand the innumerable tools and utensils that the submerged deposits have preserved.
These sites are rare and excavation techniques must be particularly fine and delicate to collect the wooden objects, which are always decomposed and very fragile.
Many trades such as coach-builders, wheelwrights, or clog makers have disappeared, with the appearance of new materials.
Here is a list of some of the current trades related to wood:
- Lumberjack is in charge of felling and cutting trees in the forest.
- Pit sawyer is in charge of cutting logs. This work is often performed at the sawmill.
- Carpenter who shapes the wood to make frames and constructions.
- Marine carpenter, who shapes parts for shipbuilding.
- Cabinetmaker, who makes furniture with veneer, sometimes curved and has some knowledge of furniture carpentry.
- Violin maker, who makes musical instruments with a resonance box (violins, double basses, guitars).
- Construction carpenter. Works at construction sites and deals with all the wooden works of a building (window frames, stairs, and various other woodworks), as well as the “classical” carpenter, who makes kitchens, bathrooms, cupboards, etc.
- Cooper, who makes barrels and casks for the conservation of wine and other alcoholic beverages.
- Woodturner creates pieces while they are symmetrically being rotated around an axis.
- Woodcarver is an ornamental sculptor artist that works the wood with gouges. He’s the one who makes for example ornaments on furniture.
Sourcing & Techniques
The basic gestures of woodworking are cutting, drilling, finishing (sanding, treatments), and assembling (mechanical or chemical).
The lumber must first be felled and then cut (delimbing, bucking, debarking, boarding). The raw boards are then dried and wrought to make them stable, clean, and flat to the required dimensions. What happens next depends on the application and the trade.
The wood to be used meets certain conditions (resistance, conservation, and protection). For reasons of resistance and conservation, trees are felled in autumn and winter because, during these periods, the tree is “at rest”, i.e. the sap circulates very slowly. The wood is then said to be “out of sap” and less subject to fermentation and insect attack. It is also recommended to cut the wood during the waning moon, when the sap is concentrated in the roots; this should further increase the “out of sap” effect.
Felled, they are delimbed and are then called logs. The log is cut into sections, it is divided into two or more parts: the foot log (lower part) and the over-logs (parts where the branches have grown).
On the cross-section, one can observe (going from the outside to the inside of the log) :
- The bark.
- Sapwood: imperfect, unusable wood.
- The perfect wood: processed and sorted according to its properties.
- Heartwood: part to be eliminated for certain jobs.
Depending on the intended use, the woods are classified according to different criteria.
Categorical classification (according to species)
We distinguish :
- Northern woods (Russian or Scandinavian);
- Tropical woods.
In each category, hardwoods and softwoods are separated also according to their density in the following classifications:
- Very light woods: balsa, poplar, willow, linden, pine, okoume;
- Light woods: alder, birch, aspen, cypress, fir, mahogany;
- Semi-heavy woods: hornbeam, chestnut, oak, maple, ash, beech, cherry, walnut, elm, plane tree, pear, iroko, niangon, doussie;
- Heavy woods: boxwood, holm oak, dogwood, mountain ash, ipe, ebony, rosewood, rosewood, ironwood.
This classification is done according to the imperfections of the wood:
- Structure rating based on the number of knots and growth anomalies;
- The effects of shrinkage due to drying. Any deformations due to drying are different according to the position of the board in the log. During drying, the wood shrinks more on the bark side (younger wood) than on the heart side (perfect wood). Drying also gives rise to cracks. There are several drying techniques (drying ovens or natural drying).
Mechanical or structural grading
Here the focus is mainly on the strength of the wood. For example, the ability of the wood to resist bending and flexing.
Compression. Axial (vertical wood grain) compression. Even though wood might have good inherent strength, when dealing with long pieces, as with any material, it still poses the risk of warping.
Traction. Axial (vertical wood grain) strength is mostly high with wood. Transverse (horizontal wood grain) strength is inherently weaker in the wood, depending on the species used.
Bending. Resistance varies according to the species and quality of the wood.
These data are especially valid for carpentry, joinery, and cabinet making.
Tape Measure: The measuring tool most used by woodworkers. A carpenter will use a tape measure and a ruler (30 to 50 cm). A cabinetmaker will use besides a ruler also a small ruler (15 to 20 cm).
Caliper: Often used when precision is important.
Compass: Widely used for circles and dimensional reports. The marking gauge is used to draw parallels or report dimensions.
Electricity has revolutionized the tools used by wood craftsmen.
Circular saw: Composed of a powerful motor turning a toothed blade. Portable versions can be carried by hand and make it possible to carry out rather coarse cuts. When used stationary it allows very precise and straight cuts.
Handsaw: Manual or electric, a handsaw is a universally used tool. From cutting branches to precision cutting for assembly work.
- Classic saw include specialized variations which are known under different names (pruning saw, saber saw, etc.).
- Japanese saws have a distinction. Their particularity is to work with them by pulling and not pushing like most western hand saws. They exist for all applications (generalist, miter, etc).
Jigsaw: Comes with a small motor that causes the blade to move up and down. Depending on the blade used (more or less narrow), it allows long straight cuts and very precise roundings.
Band saw: The blade of this saw is in the shape of a ribbon, mounted on two wheels supported by a frame, which allows for very precise cuts. Contrary to the jigsaw (which is portable), it is the wood that is moved on a tray during cutting.
A large band saw allows the logs to be cut into boards. A smaller band saw allows for the edging and scoring, there are several blades for this saw according to its use. A thin and not very wide blade allows for scoring.
Miter saw: Manual or electric, the miter saw cuts wood at a very precise angle, in order to make an assembly.
Sanding saw: A manual saw that is used to level two pieces of wood or for making fine cuts.
Scroll saw: This is the saw to use to make convoluted cuts. The thinnest blades (without lugs) are used to make lace on wood.
Chainsaw: The ideal saw for cutting large pieces of wood. Used by lumberjacks, often with a gasoline-powered engine, it is equipped with a chain with sharp teeth.
Chisels and chisel planes
Wood chisels are tools composed of a small handle (15 cm in length approximately) extended by a rectangular metal bar sharpened at the end (20 cm in length approximately with a thickness of around 0.5 cm); their width generally goes from 0.8 cm to 3 cm.
Used by all woodworking trades but more particularly by cabinetmakers who use them for delicate work (dovetail, rebate, and groove).
Mortise chisels are tools made up of a handle like the wood chisels but whose blade is heavier and thicker than they are wide. The widths go from 0.5 cm to 1.5 cm approximately. This chisel is used to make mortises.
Chisel planes are composed of a blade and a rectangular wooden body or an iron body. The blade is inserted into the body and can be positioned so as to have more or less of a “bite.” Wooden planes often have a wooden sole harder than the rest of the body, they come in all sizes, they are used for different kinds of work and in all wood trades.
Roughing gouge chisel uses a rounded chisel with a wooden or steel handle. This tool is used to round off the rough edges of the wood at the beginning of the project.
Router: is a tool that allows you to machine apart. It drives a rotational milling cutter positioned at a predefined depth or placed on a plunger. It’s used to make moldings, named for its resemblance to a router that would rotate on the cutting table. Its portable version is also known as an edge router.
Mortising machine: is a router specialized in cutting mortises with precise dimensions and positioning.
Adze: is a transverse blade hatchet used to square beams and prepare structural members.
The sanding of wood is done using flint or corundum sandpaper with different grain sizes. Each grain size is defined by a number corresponding to the number of grains per cm². The finer the grain of the paper, the larger the number written on the back of the sheet of sanding paper:
- 20 corresponds to a very large grain;
- 80 corresponds to a coarse grit;
- 120 corresponds to a medium grit;
- 220 corresponds to a fine grit;
- 280 corresponds to very fine grit.
There are papers with an even finer grain. They are used for composite materials or metals (e.g. in bodywork).
The size of the grit size of the sanding paper depends on the degree of finish you want to achieve (grainy, smooth, very smooth). When extra-fine grit paper such as 1500 or 2000 is used, it is only for the final sanding of wood with a density equal to or higher than 1 such as ebony, boxwood, and ironwood.
As a general rule, wood is porous. To stabilize it and improve its mechanical and aesthetic properties, finishes are applied in the form of chemical products. Such as anti-fungal, anti-parasitics, saturators, oils, pore fillers, stains, lacquers, or varnishes.
Buckwheat oil is a natural oil found in trees from the eastern regions and used mainly to make wood finishes.
Some interesting characteristics:
- It can be applied with a brush or rag and wiped off about 5 minutes after application (requires several coats, easily up to 5 or 6)
- dries easily and completely
- gives a finish between matte and very shiny, depending on the amount of thinner or sealer added. Up to 1/3 of sealer gives a more matte finish; no addition of thinner or sealer gives a very glossy finish;
- always gives a hard and waterproof finish.
Varnish In the buckwheat oil section, the following formula also gives a harder and silkier finish. The formula is as follows: one part varnish to three parts buckwheat oil. Sanding is required between each coat and three coats are necessary.
Related mostly to the use of machines, some of which are particularly dangerous.
Risks of diseases
The numerous handling operations of heavy load which is found throughout the timber industry can cause musculoskeletal disorders.
Woodworking itself is often the source of a noisy environment that could cause deafness if ears are not protected well.
It also exposes workers to numerous allergens (skin and respiratory) and carcinogens (wood dust being the most important).
The elimination or reduction of these risks is achieved by reducing machine noise (preferably by treatment at the source), reducing dust by dust collection at the point of emission, and eliminating carcinogens where possible.