Milling a log into lumber involves cutting the log into boards of specific dimensions. The three main methods of sawmilling are plain sawing (also known as flat sawing), rift sawing, and quarter sawing. These methods involve cutting the log into uniform, rectangular boards that are well-suited for a variety of applications.
Plain sawing is the most common method of sawmilling and involves cutting the log into boards by making parallel cuts along the length of the log. This method produces boards with a cathedral-like grain pattern that is the most common and least expensive type of sawn lumber.
Rift sawing involves cutting the log at a slight angle to produce boards with a straight grain pattern. This method is less common and more expensive than plain sawing because it produces less lumber and requires more time to produce.
Quarter sawing is a sawmilling technique that involves first cutting the log into quarters, then cutting the boards perpendicular to the growth rings of the log. This method produces boards with a straight grain pattern and a distinctive flecking or ribbon pattern known as "medullary rays" that is highly prized for its decorative appearance. It is the most time-consuming and expensive method of sawmilling but produces the highest quality and most stable lumber.
The main advantage of quarter sawing over other methods of sawmilling is that it produces lumber with a straighter and more stable grain pattern that is less likely to warp or twist over time. This makes it an excellent choice for furniture, flooring, and other high-end woodworking projects. Additionally, quarter sawn lumber is more resistant to moisture and is less likely to shrink or swell due to changes in humidity. The main disadvantage of quarter sawing is that it is the most expensive method of sawmilling and produces less lumber than other methods, so it is not practical for every application.
In addition to these traditional sawmilling methods, there is a variation of sawmilling called live-edge or natural-edge sawmilling. This technique involves cutting boards from the top of the log down towards the bottom, leaving the bark and natural edge of the log intact on one or both edges of the board. Live edge sawmilling is often used to create unique and decorative pieces of lumber, such as tables, benches, and other furniture.
While traditional sawmilling methods produce uniform, rectangular boards, live-edge sawmilling intentionally leaves the natural edge of the log intact, resulting in unique, one-of-a-kind pieces of lumber with natural edges and irregular shapes. Live-edge sawmilling can be accomplished using any of the traditional sawmilling techniques, and the choice of technique will depend on the specific log being milled and the desired outcome.
One of the benefits of live edge sawmilling is that it can utilize logs that would otherwise be considered waste due to their irregular shape or size. Additionally, the natural edge of the board can provide a structural advantage, as it can provide added strength to the finished piece.
However, there are also some disadvantages to live edge sawmilling. The natural edge of the board can be prone to cracking or splitting, which can affect the structural integrity of the finished piece. Additionally, the bark on the edge of the board can be difficult to work with and may require additional preparation or finishing.
In summary, the different methods of sawmilling logs include plain sawing, rift sawing, and quarter sawing, and the flat-sawn method called live or natural-edge milling. Each method produces lumber with a different grain pattern and has its own advantages and disadvantages. Quarter sawing produces the most stable and highest quality lumber, but it is also the most expensive and time-consuming method of sawmilling.