To explain it simply, green woodworking is a craft in which 'green' or unseasoned wood is worked into finished items using hand tools. This explanation however, may give you the impression that the only difference between conventional woodworking and green woodworking it that the wood is unseasoned. In reality, it involves a whole range of tools and principles that have virtually been eliminated from modern woodworking by the ubiquitousness and affordability of dimensioned and kiln-dried timber. Rather than being an obsolete or primitive form of work, to be recorded for posterity only, I would argue that the old techniques of processing trees manually, by riving and hewing them while 'green', pay much greater attention to the nature of the wood, allowing it to be worked with less effort and actually preserving its inherent strength and flexibility in the finished product.
Riving/Cleaving
Riving is the process of splitting wood along its length by driving an axe or wedge between the wood fibres and forcing them apart. This is a very efficient process and, crucially, the split follows the flow of the grain exactly. None of the wood fibres, which run along its length, are severed. This maximises the strength in the wood, allowing the craftsman to make very thin and light objects that are very strong. It also means that natural bends in the wood can be not only tolerated, but used to advantage, in the crank of a spoon handle or the bend of a chair leg for example. The froe is a traditional riving tool that is now rarely seen.
Hewing
Hewing is the process of flattening a timber face using a side axe, broad axe or foot adze. It comes after riving in the sequence of actions and, if the end goal is flat and square lumber, it’s the first step in the truing process, later involving a series of hand planes. Most of my work does not require flat or square boards however. This is the process that would have been used to produce large timber framing beams before widespread timber milling. The curved marks of the broad axe are often visible on timbers of older buildings.
Shaving
The shaving horse, in Ireland more commonly known as the cooper’s mare, is a foot-operated vice of ancient design. It consists of a bench, a stage and a foot-operated lever arm that clamps your work to the stage. The work can be rapidly repositioned and re-clamped, making it a particularly effective tool for shaping cylindrical objects like chair legs, axe hafts or rake stales (handles). Traditionally, these stood on three legs, in order to make them stable on the uneven woodland floor where the work was often carried out.
The shaving horse is used in combination with the drawknife, a two-handled knife that is drawn towards the user. The drawknife works well for both fine work and heavy stock removal. It is often used to perform a task that is half way between shaving and cleaving (I like the term ‘sheaving’, coined by Mike Abbot) that allows thin layers of wood to be removed quickly while keeping the long-grain fibres of the wood completely intact. This method has been developed to a fine art by the wonderful Windsor chair maker Curtis Buchanan. I would recommend checking out his free instructional videos.
Pole Lathe Turning
The pole lathe is another foot-powered device of extremely ancient origin. It is a reciprocal lathe, meaning that the wood turns in both directions, alternately. A foot pedal powers the turning motion. The wood is only cut as the piece turns towards the user, resulting in a very rhythmical sequence, applying the tool's edge on the downstroke of the pedal only. The term 'bodger', originating in High Wycombe in Buckinghamshire, was used for an itinerant woodworker who worked in the woods of, turning component parts of chairs to be sold to chair making workshops. On a pole lathe, spindle turning is done using similar tools to those used by modern turners but bowl turning is usually done with hook tools that are extremely ancient and uncommon now. Bowls turned on a pole lathe have a very characteristic quality, unlike that of bowls turned using a power lathe. Robin Wood is probably the most accomplished contemporary pole lathe bowl turner and a great person to check out if you're interested.
Properties of 'Green' Wood
Wood is softer and much easier to work when green. The work is less taxing on the body and the tools keep their edge for longer. If my wood dries out too much, it becomes firewood to me because the wood becomes so much harder as it dries that the extra effort is no longer worth it. Wood generally dries very slowly in ambient air. Drying can be slowed even more by sealing the exposed end grain where most of the moisture escapes. Before controlled kiln drying came about, fully seasoned wood, especially thick slabs, would have been expensive and hard to come by. Working with unseasoned wood was commonplace. The term 'green woodworking' only came into common usage recently (it was invented by Jennie Alexander in the 70s and popularised by Mike Abbot in his first book 'Green Woodwork - Working wood the natural way').
Another very important feature of green wood is that it shrinks as it dries. It is a popular myth that wood cannot be worked without seasoning. It simply requires knowledge of how the wood will behave over time and in fact, this behaviour is quite predictable (I plan to write a detailed post about wood shrinkage at some point so brace yourself for that). You will need to embrace the fact that your bowl or chair leg will not turn out to be perfectly round but slightly oval. If the piece must be round, it can be reshaped slightly when fully dry. The danger of checking (formation of cracks to relieve tension that has built up in the wood during shrinkage) can be largely eliminated when the properties of wood are understood.
Shrink Joints
The shrinkage of the wood can be used to one’s advantage. Green wood chair makers combine seasoned components, made ahead of time, with unseasoned components to create very tight, glue-free joints. A mortise in a green chair leg will shrink tightly around the dry tenon of the stretcher to create a joint that is virtually impossible to separate.
Pure Satisfaction
On a personal note, I enjoy the lack of separation between me and the wood conversion process. I am able to literally make things out of trees: I control the whole process from start to finish. It is very much less satisfying to go down to the timber yard and buy dimensioned lumber from some unknown source. Knowing where the tree stood also adds an extra element of depth to every piece, which is something that is hard to describe but its something I love. When I collect a windblown tree from somebody's garden, I always try to make something from its wood for the tree's former owner.
In conclusion, green woodworking has been experiencing somewhat of a revival in recent years and I'm confident that the value of understanding these traditional woodworking principles will never be forgotten.