From Firewood to Project Wood - Part 1

Flat sawn, plain sawn, rift sawn, quarter sawn... what does it all mean? Cutting a small log it into boards on your bandsaw is a great way to get a better understanding of the different types of sawn boards. This process allows you to simulate what a saw mill does when cutting logs into boards, but on a small scale. And the best part is you should end up with some great wood for a small project.

For me this process started with a walnut tree my brother removed from his property. It wasn't a great tree, but it had some crooked sections that I felt compelled to see what they looked like inside. After cutting a few sections out with a chainsaw I started searching the internet for tips on sawing the logs. The process of safely running the wood through a bandsaw is fairly straightforward, but I'll go into those details later (acutally, in a future post). Then I said to myself, 'hey, I should quarter saw this!' My attention quickly turned to the different techniques of cutting a log. I was in for a surprise!

Conflicting information appeared almost immediately. After wading through many pages of descriptions and forum arguments, I came to the realization that the terms Plain and Quarter are used to describe both the properties of a board and the techniques used to cut a log. Plain Sawing and Quarter Sawing are both techniques used to cut a log into planks. Plain Sawn (aka Flat Sawn or Slab Sawn), Rift Sawn, and Quarter Sawn are terms used to describe the angle of the grain in relation to the face of the board. Notice I differentiate them by using sawing (present tense - the act of cutting the log up) verses sawn (past tense - the board was cut with the resulting grain). We'll start with what is most important to the woodworker, which is actual grain angle found on a board.

Plain Sawn - Also referred to as Slab Sawn and Flat Sawn. The grain runs between parallel to and 30 degrees from the face. The resulting board has what is commonly referred to as 'cathedral' patterns or 'V' shape grain that is visible on the surface. Plain sawn lumbers tends to be prone to warping, cupping, and expansion/shrinkage issues. It is the easiest and most efficient to cut, and the most common found.

Rift Sawn - The grain in Rift sawn board is angled between 30 and 60 degrees from the face. This results in long straight lines of grain, while minimizing the rays and fleck resulting from the medullary rays of a tree. Rift Sawn boards are quite stable.

Quarter Sawn - When the grain is 60 to 90 degrees from the face the board is classified as quarter sawn. These board are very stable with low expansion and contraction (most happens within the thickness of the board). These board will prominently display the medullary rays of the wood. These rays are sheets or ribbons that pass perpendicularly to the growth rings and appear as specs, spots, fleck, or figure in Quarter Sawn the wood.  

The Wood Whisperer discusses these board types in the video titled 'A Lumbering Feeling'. Notice how Marc doesn't mention anything about how the log was cut, simply about what the grain looks like and the resulting properties.

The technique used to cut the log is described in the Woodworkers Guild of America video below. While watching the video, take note how the middle board using a Plain Sawing technique actually results a Quarter Sawn board (the board is just twice as wide as it would be in the quarter sawn technique).

This video from Frank Miller Lumber explains the same quarter sawing process and details where the Quarter Sawn board and the Rift Sawn boards will come from.

Wood Treks also has a nice video on the subject available here:

Most of the confusion I found relates to the following diagram, which seems to be wide spread on the Internet. This, and similar drawings, show Rift Sawn boards as boards that are sawn in a radial pattern out from the center. This definitions goes against any credible description of the Rift Sawn, as previously defined. My current conclusion is that this diagram is simply wrong. The method labeled Riftsawn in this diagram is actually commonly referred to as Radial Sawing or Perfect Quartering (because it results in every board being Quarter Sawn). Notice how the diagram for the Quarter Sawing  process is different than previously detailed. There are several different Quarter Sawing techniques that are commonly used to maximum the yield of Quarter Sawn lumber.

The bottom line is this subject is constantly debated as people have developed their own definitions over time. In a monetary transaction where the grain pattern is important to both the buyer and the seller (like a customer commissioning a piece that shall feature Quarter Sawn wood), it is important that both parties agree on the definition early to avoid potential conflict later.

And all I wanted to do was take a old tree destined for firewood and make project wood! I guess that is part II of this story...