How is wood prepared?
Rough-sawn wood to be used in various projects goes through a process of size reduction and levelling before it can be further shaped and finished to fit into a woodworking project.
Often, electrically powered machines are use for this procedure, but planes are still used in some workshops and by some DIYers.
What is sizing and truing?
Sizing means cutting the wood to the right size, whether this is a standard size in which the wood is sold, or the right size for a particular woodworking project.
Truing means making every face and edge of the piece of wood perfectly rectangular, or ‘square’.
Every piece of stock has two faces, or sides, two edges and two ends.
What are faces, edges and ends?
The face of a piece of wood is either of its larger two long sides, the edges are the long narrow sides, and the ends are the two short edges.
When is square not a square?
A piece of wood that has been ‘squared’ is usually not actually square in shape, but square in the sense that each of its sides and edges is perpendicular – or at 90 degrees, or right-angles – with its adjoining edges.
Power tools and hand saws
Large power tools, such as bench saws, the jointer (also known as the surface planer), and the thicknesser (or thickness planer), and sometimes the manual hand saw are used to initially cut rough stock to size.
However, some rough stock may be too big to go into a machine. For instance, most jointers can only take stock up to a maximum of either 150mm (6”) or 200mm (8”) wide.
Rough stock that is wider than the machines' capability is often initially sized with a hand plane.
When sufficient reduction of the wood had been made, it can go into the jointer, unless the operation is entirely manual, in which case, other hand planes are employed to further reduce and true the wood.
The different states of wood
The different states of the wood as it progresses through its preparation for sale or for use in a project can be summarised as:
1 – Rough stock, or rough sawn
The wood has rough surfaces produced by the power saw or hand saw
2 – Planed square edge (PSE)
Just one edge is planed accurately, making it possible to place the wood in a thicknesser, or to mark out and cut other edges precisely in relation to the first.
3 – Planed both sides (PBS)
Both sides are planed but not the edges, which are left rough-sawn.
4 – Planed all round (PAR)
All the sides and edges are planed square, straight and level, leaving a relatively smooth finish, and the wood ready for use.
Wood is available for purchase in all four stages.
Woodworking hand planes often have a major role in the preparation of the wood in this way, and later in further sizing and smoothing wood, and cutting and smoothing any grooves, mortises, mouldings and chamfers as a woodworking project progresses.
The order of planes
Hand planes can be used in a sequence on each side and edge of rough-sawn wood. Each newly levelled surface becomes, in effect, a reference point to ensure the next side or edge is "square" – perpendicular with its neighbours and parallel with the opposite side or edge.
Here's Wonkee Donkee's plane guide to the order of use:
1 – Scrub plane
The scrub is used first to remove large amounts of wood quickly from rough stock.
2 – Jack plane
The jack plane continues the job of reducing, but more accurately and more smoothly.
3 – Fore plane
The fore plane is longer and can cut off the high spots while bridging the low points, progressively straightening the wood.
4 – Jointer plane
The jointer, or try, plane does the final "flattening", giving a perfectly straight face or edge.
5 – Smoothing plane
A smoothing plane gives the final, smooth finish to wood.
Sometimes a scraping plane or polishing plane, which have their blades set at a very high angle, might also be employed to give an even finer finish.