Building on the first post in this series, it’s time to explore Graham Blackburn’s second pillar of design: Construction. When one thinks of construction in woodworking, the first thought is inevitably joinery. While joinery is definitely one element of the construction of a piece of furniture, as you might expect, there’s more to the equation.
From Graham Blackburn’s perspective, construction is not just focused on joinery but, rather a combination of: Techniques, Joinery and Material Knowledge.
Some examples of construction techniques would be:
- Building completely with solid wood (i.e. large pieces or glued up panels) – this produces results that are prone to split and crack especially when housed in modern heated structures
- Frame and Panel construction – in contrast, this technique is used for dimensional and planar stability and helps avoid the problems of wood movement encountered with all solid wood construction. As an example, the stiles in a frame and panel door are made narrow and usually run the entire height of the door because wood moves very little in length therefore the height of the door will remain fairly consistent. For the same reason, the rails of a door are usually arranged between the stiles so that there will be a minimal change in the width of the door (mainly due to small changes in the width of the stiles)
- Cabinet Making – In Blackburn’s parlance this is actually veneering to create larger panels without the need for frame and panel construction which offers no real advantage in many cabinet applications. The use of veneers allows different wood species to be used to create stable panels and also conserves potentially rare materials used for veneers
- Other construction techniques include turning, lamination, coopering and a host of others.
The takeaway here is that the technique of construction is one of the elements that contribute to the design of a piece. One interesting point that Blackburn shared on construction techniques was that in historic times, the various guilds (i.e. Turners Guild, Joiners Guild, Cabinetmakers Guild, etc.) actually drove the design in particular styles of funiture due to the limits of what they were allowed to do within their respective guilds. Therefore, a piece with all turned elements would only come froma member of the Turners Guild.
Closely related to the technique of construction are the qualities of the material to be used. In Blackburn’s view, one can never know enough about that materials used in the construction of furniture. One great source of information on wood and its properties is available online by searching for “Wood Handbook”.
The most common characteristics of a wood are its shrinkage and expansion rates. Many woodworkers know that wood moves with moisture more across the grain than with it but, did you also know that it will move more when harvested from toward the outside of the tree? As a result, quartersawing wood (where the growth rings are nearly perpendicular to the face of the board) produces the most stable boards because the outside of the tree is the smallest possible dimension of the board (its thickness) – thus a quartersawn board expands and contracts mainly only in thickness.
While the aforementioned charactistics of wood are important, there are many others to consider when choosing a piece or species of wood for a furniture design. Figure, color (and the possibility for change), cost, hardness, strength, workability, desnsity, flexibility, toxicity, etc. – all of these things can contribute significantly to the design choices in a piece of furniture.
Last, but not least to be considered, is the joinery used in the construction of a piece of furniture that is being designed. For the best possible designs we need to know as much as possible about various woodworking joints and joinery techniques so that we can choose the best joint for the intended purpose.
Unfortunately, most woodworkers tend to have a limited joinery vocabulary. This is mainly due to more prevailant machine use in woodworking today. Machines were generally not designed to produce joinery. Most woodworking machines are designed for and best suited for a single purpose.
The strongest woodworking joint is the one with the least amount of material removed from each part. Many of the best joints for specific purposes are necessary to make or, at least fit by hand. So, in order to produce the best furniture designs BLackburn feels that it is important for all all woodworkers to study woodworking joints and to develop this joinery vocabulary. Also important, is the development of efficient accurate methods for creating these joints either by machine, by hand or via a hybrid approach.
In a future post we’ll explore Blackburn’s third Pillar of Design: Proportion.