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    Determining Grain Direction





    By Chris Gochnour

    Wood’s beauty and appeal can be credited to the uniqueness and diversity of its grain. These same virtues, however, turn to vice when it comes to surfacing and smoothing lumber. The secret to achieving smooth surfaces with machine and hand tools is cutting in the direction of the grain. Sometimes grain can change direction on a single board. Depending on the species you’re working with, grain direction is not always obvious.

    While you have a 50:50 chance of success by guessing which direction the grain runs, you can increase your odds greatly by studying a board for clues, listening and feeling as you mill the wood or work it by hand, and making midcourse corrections when necessary.

    Rays, vessels, and figure are indicators

    You can determine the grain orientation of various hardwoods by observing their physical characteristics.

    Examine the face

    In some hardwoods, you can determine the grain direction by simply looking at the rays, which are wood cells that radiate from the center of a tree to its perimeter. They appear vividly in species such as oak, beech, and sycamore as dark, solid specs of varying lengths. Rays are visible on the surface of a plainsawn board in cross section, sandwiched between the fibers. Therefore, the long, narrow marks point in the same direction as the fibers, making them the most reliable indicator of the direction of the grain.

    Examine the rays


    Rays can be difficult to make out on some species, in which case I look for vessels to determine grain direction. Vessels are woodcells that extend linearly in hardwood and appear most prominently in species such as mahogany, walnut, and butternut. They
    appear on the surface of the board as long, open tubes and on the end grain as small, open pores. Vessels align with the direction of the grain, so identifying the direction vessels travel also indicates the direction the grain travels.

    Look at the vessels
     

    Because many species display neither rays nor vessels to the naked eye, figure (which often is referred to as grain) is the last characteristic I look at to assess grain direction. Figure is created when the varying densities and color of the annular growth rings intersect with the surface of the board. On the face of a plainsawn
    board, figure often appears in cathedral patterns. Most of the time, figure will follow the grain, so it can be used as an indicator. However, it’s not uncommon for grain to
    run opposite the figure, so this isn’t always the most reliable source. In woods that don’t have prominent vessels or rays, such as cherry, maple, and alder, figure is the best characteristic to go by.

    Examine figure
     

    How to read a board

    When cutting the surface of a board with a jointer, planer, or hand tools, you should use rays, vessels, and figure to determine the best direction to cut.

    A good place to start is to inspect the edge adjacent to the surface you are working. The majority of the time, rays, vessels, or figure will travel diagonally across the edge of a board, revealing the grain direction. This will indicate how a board should be oriented so that the surface cut lays down the fibers in the path of the blade. This same rule can be applied when working the edge of a board. Inspect the adjacent surface to determine the grain direction.

    Inspect the edge
     

    In situations where the edges of the board cannot be seen, such as when handplaning glued-up panels or tabletops, I observe the orientation of the growth rings on the board’s end in relation to the cathedral patterns on the surface to determine grain direction. If the growth rings arch upward when looking at the end of a board, your cut should be made into the cathedral points on the surface. If the growth rings arch downward at the end of the board, the cut should be in the same direction the cathedrals are pointing.



     

    Keep track of grain as you work

    When milling lumber, you will have the best success producing smooth, tear-free material if you keep track of the grain direction on each board. When surfacing lumber, mark the edge of the board with a diagonal line that shows the direction of its grain. You can use the mark to determine the orientation of the board quickly when feeding it through a planer or jointer. When planing or jointing the edge of lumber, draw the diagonal mark on the face of the board. This marking system is especially useful when milling large quantities of wood. Make sure each piece is marked
    properly, and keep the wood stacked with the grain running in a consistent direction.

    It’s also important to know that the grain runs in the opposite direction on opposing surfaces of a board. So you must flip over the board, end to end, to maintain the same grain orientation. Flipping the board sideways will reverse the grain direction.

    More than meets the eye

    While rays, vessels, and figure can be a good indicator of grain direction, some woods invariably will deceive you. Also, it is rare to find a board in which all of the grain is going in the same direction. As I work, I watch, feel, and listen to the progress of my cut, always assessing how the wood is responding to the blade. If I hear the
    snapping sound of breaking fibers while using machines, I ease up on the speed of the pass, lighten the cut, and try feeding the board in the other direction on the next cut. With properly tuned equipment, moderate cuts, and a slow feed rate, boards with changing grain direction can be accommodated.

    Sometimes you will come across a board that tears out in every direction. This is especially the case with highly figured boards, such as bird’s-eye maple or curly woods. Once you’ve discovered that you’re going to get tearout in either direction, you can try a few tricks. One is to dampen the surface of the board before passing it
    across the blade. You also can try sending the board across the blade at a skew; that way you are cutting across the grain rather than attacking it head-on.

    Handplanes are more sensitive than machines, so you will feel when a cut is going against the grain. Cutting with the grain should feel smooth, while cutting against it feels rough. Handplaning also is advantageous because you can reverse the direction of your cut when grain changes midway through a board. I try to avoid this
    practice, though, because I prefer to take long, continuous strokes. With time, identifying the direction of the grain and working in its favor can become second nature, even with the most complex grain patterns. Keep in mind that in the real world, grain direction can be unpredictable. The goal then is to determine the direction that the majority of the fibers lay and work them in the most
    favorable direction.

    Photos by Michael Pekovich; Drawings by Vince Babak

    From Fine Woodworking #172


    Chris_Gochnour