Woodwork

Wood carving (xyloglyphy) is a form of working wood by means of a cutting tool held in the hand, resulting in a wooden figure or figurine, or in the sculptural ornamentation of a wooden object. The phrase may also refer to the finished product, from individual sculptures, to hand-worked mouldings composing part of a tracery.

Some of the finest extant examples of early wood carving are from the Middle Ages in Italy and France, where the typical themes of that era were Christian iconography. In England many complete examples remain from the 16th and 17th century, where oak was the preferred medium in this case

Figural carving seems to have been widespread. The carving to represent one's god in a tangible form finds expression in numberless ways. The early carver, and, for that matter, the native of the present day, has found a difficulty in giving expression to the eye, and at times has evaded it by inlaying this feature with coloured material.

Basic tool set

• the carving knife: a specialized knife used to pare, cut, and smooth wood.
• the gouge: a tool with a curved cutting edge used in a variety of forms and sizes for carving hollows, rounds and sweeping curves.
• the coping saw, a small saw that is used to cut off chunks of wood at once.
• the chisel, large and small, whose straight cutting edge is used for lines and cleaning up flat surfaces.
• the V-tool used for parting, and in certain classes of flat work for emphasizing lines.
• the veiner: a specialized deep gouge with a U shaped cutting edge.
• sharpening equipment, such as various stones and a strop, necessary for maintaining edges.

A special screw for fixing work to the workbench, and a mallet, complete the carvers kit, though other tools, both specialized and adapted, are often used, such as a router for bringing grounds to a uniform level, bent gouges and bent chisels for cutting hollows too deep for the ordinary tool.

Woodturning

When woodturning, it is important to wear certain personal protective equipment (PPE). Loose clothing should not be worn, all jewellery should be removed, and long hair should be tied back. Wood shavings generated during turning will also need to be periodically removed.

• Eye protection is a necessity when woodturning. There are several PPE available for eye protection such as safety goggles, glasses and visors, some of which feature built-in respirators. Although all of these are adequate, for the highest level of protection, a visor that protects the entire head from dust and debris should be worn.
• Respiratory equipment and Dust collection systems are also important when woodturning or doing any type of woodworking that creates dust. This can range from a simple disposable dust mask, to a full face helmet with built in respirator. Most stand alone respiratory equipment will interfere with dust shields and visors, so devices that incorporate both are available. Many woods create dust that is actually a health hazard. For example, cocobolo (granadillo) dust is known to be toxic (toxic shock). Many people are sensitive to oils carried in walnut, locust, and oak sawdust. Long term exposure to fine wood dust has also been linked with an increased risk of developing cancer.
• Ear protection Compared to other power tools, a lathe is a quiet machine. Ear protection should be used if noise is excessive, this may be due to motor (fan) noise from a shop dust collector, or the combination of wood and tool being used.
• Hand/Skin protection Gloves should not be used with rotating equipment, since there's always a risk of getting tangled in the machine. Nevertheless, some woods provide splinters that not only puncture skin, but also cause festering sores and/or skin irritation. Polishes and finishes used in woodturning can also be harmful or irritant to skin, often containing organic solvents such as methanol, turpentine and toluene. This subject continues to be debated in the community.
• Foot protection. Protective footwear, often leather steel-toe boots, is required for any type of shop activity.

Safe usage of a lathe also depends on the operator knowing proper techniques and being aware of the limitations of both the machine and the workpiece. For example, using a high spindle speed with an unbalanced workpiece may cause the lathe to vibrate dangerously. Spinning a large workpiece too fast may cause it to explode. Inappropriate use of tools such as gouges and skew chisels can cause a catch, where the tool bites suddenly and aggressively into the wood in an uncontrolled manner. This exerts very large forces on the workpiece, the tool, the lathe and the operator, often causing the workpiece to break apart or tear free from the lathe or pulling the tool out of the operator's hands and throwing it through the air.

Wood finishing

Wood finishing refers to the process of embellishing and/or protecting the surface of a wooden material. The process starts with surface preparation, either by sanding by hand (typically using a sanding block or power sander), scraping, or planing. Imperfections or nail holes on the surface may be filled using wood putty or pores may be filled using wood filler. Often, the wood's colour is changed by staining, bleaching, ammonia fuming and a number of other techniques. Some woods such as pine or cherry do not take stain evenly, resulting in "blotching". To avoid blotching, a barrier coat such as shellac or "wood conditioner" is applied before the stain. Gel stains are also used to avoid blotching.

Once the wood surface is prepared and stained, a number of coats of finish may be applied, often sanding between coats. Commonly used wood finishes include wax, shellac, drying oils (such as linseed oil or tung oil), lacquer, varnish, or paint. Other finishes called "oil finish" or "Danish oil" are actually thin varnishes with a relatively large amount of oil and solvent. Water-based finishes can cause what is called "raising the grain" where surface fuzz emerges and requires sanding down.

Finally the surface may be polished or buffed using steel wool, pumice, rotten stone and other polishing or rubbing compounds depending on the shine desired. Often, a final coat of wax can be applied over the finish to add a slight amount of protection.

French polishing is not polishing as such, but a method of applying many thin coats of shellac using a rubbing pad, yielding a very fine glossy finish.

Special tools used to apply wood finishes include rags, rubbing pads, brushes, and spray guns. The processes involved and the terminology for the materials used are quite different in Britain than the processes and terms used in the USA. For instance, the process of replicating the look and feel of traditional French polished wood is more commonly done in the UK by "pulling over" precatalysed lacquer, within 24 hours of spraying, whereas in the U.S. a "rubbed" finish is more common.

Types of finishes

There are basically three types of finish:

• Evaporative
• Reactive
• Coalesion is meant to perform.

Wax is an evaporative finish because it is dissolved in turpentine or petroleum distillates to make the familiar soft paste. After these distillates evaporate all that's left is the wax.

Reactive finishes use solvents such as white spirits and naphtha. Oil varnishes and linseed oil are reactive finishes which change chemically when they cure, unlike evaporative finishes. At cure, the solvent/thinner evaporates and the resins cluster tighter together, and then a chemical reaction occurs causing the resins to cross link in a different chemical format—like loose scaffolding that suddenly bolt together. Scuff sanding is necessary between layers of cured finish so that subsequent applied layers have something to grip on to effectively. The solvent won't re-dissolve the cured film, eg, white spirits does not soften cured oil based varnish.

Note that pre-catalysed and post catalysed "lacquers" (aka acid catalysed lacquers) are reactive finishes. The term lacquer is, in this sense, used inconsistently from product to product.

The oil based varnishes dry from the top down by reacting with oxygen. The catalysed lacquers dry from the bottom up (which is like the evaporative finishes) and the solvents migrate upwards to the film surface and then out leaving behind molecules that then crosslink.

Tung oil and linseed oil are reactive finishes that cure by reacting with oxygen, but do not really form film finishes when cured.

Water based finishes generally fall into the coalescing category.