Plain Sawn or Quartered?
Have you ever wondered what the difference is between plain sawn lumber and quarter sawn? Have you wondered why the prices at your local lumber yard are higher for quarter sawn? Have you ever wondered which one you should use for the project you want to build? Well here is some explanation and information that will hopefully clear things up and maybe help you decide on materials for your next project.
First off, what is the difference between plain sawn and quartered lumber? The difference is the way they are sawed from the log. This difference caused by sawing technique will affect the lumber's appearance, properties, and final use.
Plain sawn lumber is the most common form of lumber for one main reason, production efficiency! The fact is that it is much faster to plain saw lumber and it creates less waste. With money being the driving force behind everything in this world, the name of the game is to get the most out of your raw materials in the fastest possible time.
When the log is rolled onto the carriage it is positioned and secured for cutting to begin. A slab is cut off first, then the boards are cut one after another until just before the pith (aka heart) is reached. The log is then rolled so that the opposite face is positioned for the next series of cuts. Sometimes the logs are sawed completely into boards, but most of the time there will be a piece of "blocking" left from the center, this is called "boxing the heart." After the log is sawed down to the specific blocking thickness, it is then rolled 90 degrees and more boards are sawed. (For a numbered cut sequence see figure 1)
The board will show a terrific grain pattern when plain sawn. The annual rings of growth will be anywhere from almost parallel with the face of the board to about 60-70 degrees perpendicular to the face. (see bottom of figure 1)
This is the simplest, fastest, and most efficient way to saw a log into boards. I have cut 18" diameter logs this way in 45 seconds, for the time the log hits the carriage to the time I unload the blocking. If I am sawing 6" cants for our bull-edger, I can zip the log down to size in 15-30 seconds.
Quarter Sawn Lumber
Quarter sawn lumber is perhaps most famous from Oak. The ray flecks that are revealed when quarter sawn, are a prize for many furniture craftsmen (and craftswomen). Besides Oak there are a handful of other species that display a unique appearance when quarter sawn. These unique features are usually only displayed on a quarter sawn board.
But in a production environment, beauty is cast aside for more yield from a log and more production in less time. This is the main reason why you pay more money for quarter sawn lumber. If it takes longer to saw a log and produce less board footage while creating more waste the company will have to charge more money to make up what they lost production. The secondary reason for higher prices are because craftsmen like us will pay more for this lumber, so that we can take advantage of it's character and better properties.
"There is more than one way to skin a cat." as the saying goes. Well, there is more than one way to quarter saw a log also. I will just quickly explain one technique, because all the details of sawing logs to lumber can fill a book or two.
This is the most common way of quarter sawing that I have seen. The first step of this method is to quarter the log (see figure 2). Then each individual quartered section is placed on the carriage in a position so that the annual rings of growth are as close to 90 degrees perpendicular to the face of the boards as possible.
The grain on the face of a quarter sawn board will be tight, straight, parallel lines running the length of the board. And if the rings are very close to 90 degrees from the face, then the famous ray flecks of Quartered Oak, we be proudly display along the face of the board.
One other technique involves re-adjusting the quartered section after each board is sawn. This way they are taking a board then a small wedge shaped slab, then another board and so on. This way the rings are always 90 degrees to the face. But there is a tremendous amount of waste created.
Which Should I use?
Well this really depends on your taste and on your project and maybe even your budget.
If you are buying your lumber kiln dried, then you will have less to worry about. But if you are buying green or air dried, then your main concern should be on stability. The quarter sawn boards will generally have less movement (shrinkage) when drying. The way the cells are aligned will cause the quarter sawn board to shrink a little bit in width and very little in thickness. Quarter sawn boards are also much less prone to warping.
Plain sawn boards have grain in multiple directions, this will cause un-even drying and in turn cause the board to warp (cup, twist, and bow). The shrinkage rate is also much more pronounced in plain sawn boards. Due to the grain's orientation in the board, the board will shrink considerably in thickness as well as width.
If you are buying kin dried lumber then you should be some what safe; the boards have done the majority of their movement and all you have to worry about is what they will due when they absorb moisture from their environment and swell. Again, the quartered lumber will mainly swell in width, and the plain sawn lumber will swell in width and thickness and possibly even warp.
Besides the stability, (and sometimes ray fleck that is displayed), another great feature of quarter sawn lumber is if you have to glue up boards for a larger sized panel the grain is easily matched to look seamless.
But with proper precautions taken during assembly (using joinery that will allow slight seasonal movement of the wood), you can use either quarter sawn or plain sawn lumber in your project and have a beautiful piece of furniture that will last for generations.