Eastern white pine

Eastern white pine


When the early European explorers discovered America,” one of the most important resources was eastern white pine (Pinus strobus) timber. These trees were tall, straight, and plentiful.

They would provide excellent masts for sailing ships (white pine is strong and limber) as well as much of the lumber needed for internal framing and sheathing for ships. This resource was harvested over the past 250 years providing the housing, farm buildings, and furniture and cabinet needs of the growing U.S. population. Laura Wilders book House in the Big Woods” is about this resource when it was just beginning to be harvested in the late 1800s in Wisconsin.

Today, white pine is not a dominant tree in most of our forests, but it has been making a good recovery and now we are beginning to see some very nice size trees. About half of the pine lumber comes from New England and a third from the Great Lakes states; the remainder from the Middle Atlantic and Southern Atlantic states.

White pine furniture, millwork, and cabinets remain popular in the U.S. markets. Although pine can be used for structural lumber (2×4, 2x6s, and so on), the clearer wood is more profitable if used for secondary manufacturing. The knotty material, however, often is used in structural products. The key to profitable and wise utilization of pine timber today is to cut it efficiently into valuable lumber.


Processing Suggestions and Characteristics

Density. Eastern white pine is a light weight softwood, averaging about 23 pounds per cubic foot at 8 percent MC. This is one-half of the weight of oak.

Drying. Although EWP dries very quickly with almost no risk of warp and checking, drying must be carefully controlled, because of color concerns. Chemicals in the wood are oxidized, if drying is too slow, turning the wood rather dark brown. Such coloration is called brown stain, coffee stain, or kiln burn. Kiln-drying should begin ASAP after sawing, with relative humidities in the drier being quite low to avoid the stain. Low temperatures (under 130 F when the wood is wet) are also required to avoid darker coloring.

Shrinkage in drying is under 4 percent.

Final moisture contents for EWP should be between 8 to 9.0 percent MC. Slight MC variation is permitted due to EWPs low shrinkage. Drying below 8.0 percent MC increases the risk of shelling and grain tear-out; drying above 9.0 percent MC increases the risk of subsequent shrinkage during manufacturing or in use.

Gluing and Machining. EWP is one of the easiest woods to glue; it is very forgiving if surfaces are not quite perfect. Pressure must be uniform and not too high. Any commonly used wood adhesive will perform very well.

Because of the uniform texture and low density, EWP machines well, provided the MC is correct. Tools must be sharp; likewise, sandpaper must not be worn. Due to swirly grain around knots, the rake angle is often a few degrees larger than for higher density hardwoods. Excessive pressures from knives or machine components can cause shelling or raised grain.

Stability. EWP is one of the most stable woods in North America, changing about 1 percent in size for each 5 percent MC change running across the grain parallel to the rings (tangentially), and about 1 percent size change for each 15 percent MC change across the rings (radially). This is one of the most stable woods.

Strength. EWP is one of the weaker native softwoods. Bending strength (MOR) averages 8600 psi. Hardness averages 380 pounds. Stiffness (MOE) averages 1.2 million psi.

Color and Grain. The wood of EWP does have obvious annual growth rings but not as obvious in contrast as some of the other pines. The wood will have red knots (the branch was alive when the tree grew around it) and black knots (the branch was dead and the knot is loose). The wood, when fresh, is very light in color. After drying the wood is typically very light brown with a reddish hue at times; exposure to light darkens the wood color further. The grain is usually quite straight; warping risks are minimal, except in areas containing compression wood.

Historical Tidbits. Eastern white pine resource in the northeastern U.S. was a critical resource for the sailing-ship dominance of the British in early European settlement of the U.S. Trees that were straight and branch free for many feet up the set, were marked by the Crown and could not be cut by the early settlers, even if the tree was in the middle of a farm field. Supposedly, there were a lot of trees cut down in the middle of the night. Also, some historians suggest that the famous Boston Tea Party was “fueled” by this harvesting ban.

After the Revolutionary War, the British moved their eastern white pine operations to the region we now call Green Bay, Wisconsin, and operated there for many years, shipping through the Great Lakes and the St. Lawrence River.

This post appeared first on http://www.woodworkingnetwork.com

Leave a Reply

Your email address will not be published. Required fields are marked *

This website nor its owners are an actual service provider, this website is a referral service. When you place a phone call from this website, it will route you to a licensed, professional service provider that serves your area. For more information refer to our terms of service.

© WoodFloorRefinishing.info

(877) 959-3534