Open-grain vs. closed-grain wood – FineWoodworking

What is the difference between open-grain and closed-grain wood? Understanding wood at a cellular level is not necessary for woodworking, but that knowledge gives me an additional tool in my arsenal. Having a deeper relationship with the material you work with can influence the selection and use of that material, which can make a big difference in the final product. Wood selection is not just about color. Furniture is an interactive experience, so using different types and creatively choosing textures can completely change the look and feel of your furniture. Depending on the application, the type to be used for adhesion, finishing, etc. is determined. Open-grain and closed-grain woods are just one of many distinctions between tree species, and a great example of the importance of choosing the right material for your project.

under the surface

All wood species are degraded similarly at the cellular level, with differences seen in how different types of cells are distributed throughout the wood. I often liken woodgrain makeup to a stack of straws. Trees need pathways to feed their leaves and branches. These pass through the trunk and extremities. Most woodworkers make use of wood, especially kiln-dried wood, for tree trunks. Differences between conifers and broadleaf trees can be found by examining the cell composition.

Conifers, or conifers, have cells called tracheids. These act as conductors of nutrients supplied to the tree. Individual tracheids are usually visible with a magnifying lens. To the naked eye, they appear as different textures. Our consideration of open and closed grain is primarily related to texture. Large holes are more common in earlywood grown early in the season. During this season, the larger, thinner-walled tracheids supply the tree with more nutrients. Later in the season, the tracheids become smaller and the walls thicker and denser, giving the tree strength and rigidity in colder weather.

Earlywood and latewood can be distinguished by the rings on the cross-section of the tree. Resin canals, or resin ducts, are unique to conifers and more pronounced in tree species such as pine. The majority of conifers can be considered closed-grain wood, as the tracheids are only 20–60 micrometers wide in most tree species.

Broadleaf trees have a wider variety of cells, including vascular elements, which are large conductors with thin walls. They are unique in that the cells are open end-to-end, unlike tracheids which are closed. Vascular elements are visible to the naked eye and appear in the cross section or butt end of the wood. These open-ended cells are called pores. According to this term, hardwoods and softwoods are porous and non-porous woods. Because hardwoods contain large amounts of both small and large pores, they are often considered open-grain woods. Fibers surround these cells and provide stiffness.

Ray cells run outward from the center of the tree, so they can be seen from the surface of the tree. Because these conductors have thin walls, they can become brittle and develop large open pores. The final cell types that are important in distinguishing between closed and open grain timber are: tyros: Foam-like cells that exist between early and late wood and interfere with the conductivity of blood vessels. These are more pronounced and visible in certain species such as white oak.

what we can see

Open-grain and closed-grain woods are generally classified according to what is visible to the naked eye. Cellular composition helps us to further identify these forests and understand what we are seeing. Visible pores are found in open grain woods such as oak, ash, and hickory. Tightly grained woods such as maple, walnut, and cherry have pores that are invisible to the naked eye.

When to Use Open Grain Wood or Close Grain Wood

These differences are important when choosing wood for a particular application. Aesthetics are the main reason for choosing between open and closed grain lumber for most furniture manufacturers. But there are also some practical applications. White oak contains a lot of tylose cells that prevent water from passing through, making it ideal for whiskey casks. The concentration of pores in earlywood makes it easier to split the wood to make baskets. Wood is great for carving because the pores of the same size are more evenly distributed. Many flooring applications wear differently over time due to varying cell wall thicknesses.

It is also important to consider the texture of the wood when using adhesives and finishes. Pine wood can have an uneven finish due to resin channels and variations in density between earlywood and latewood. Open grain woods may need to be cleaned with diluted adhesive prior to final bonding to achieve a non-porous bonding surface. I recently chose beech wood, a tight-grained wood, for a project that was frequently exposed to moisture and paint. The dense wood is also great for food-safe cutting boards and utensils. There are many ways to deal with or avoid these factors, but anticipating potential problems and using seeds that work to your advantage are just as important as choosing the right joinery.

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	All about wood science In the words of R. Bruce Hoadley, “A tree comes from a tree. This is the most important fact to remember in understanding the nature of wood.”
	Tips for finding the best grain on your board Mason McBrien’s tips help woodworkers get the most out of their stored wood without sacrificing beautiful grain choices.