Month: December 2018

Santos mahogany (scientific name: Myroxylon balsamum) is also called balsamo (English) and palo de balsamo (Central America) in the lumber business. Although this wood is not related to Honduran (or true) mahogany or to African mahogany, it is a rich dark mahogany colored wood and is actually a bit harder then Honduran mahogany. The wood has interlocked grain, which gives it a strong ribbon-like pattern.

The tree, which is in the legume family, is widespread, ranging from southern Mexico southward through Central American and continuing down to Argentina. Trees are usually short, 50 to 65 feet tall, and moderate in diameter, 18 to 36 inches. The typical log produces a large amount of knot-free lumber.

This tree is well known for the resin, called balsam or balsamo, that it produces. In fact, Sixteenth Century Spanish explorers shipped balsamo to Europe, where it was claimed to have extravagant medicinal properties. Indeed, the resin has a spicy aroma, somewhat similar to vanilla. Much of today’s resin production comes from in El Salvador, although plantings in Africa and Southeast Asia are now producing this resin as well. Today, the resin is used in salves, cough syrup flavorings and perfumes. When tapping the tree for the resin in the past, which required the bark to be scored deeply, the tree was severely injured and died. As a result, the availability of this excellent wood is quite limited, although it has been recently planted in plantations.

The hardness of this wood makes it ideal for flooring, although it is also sometimes used for furniture, interior trim, and turnery.

Processing suggestions and characteristics

Density. The density of this wood is quite high (around 60 pounds per cubic foot). In fact, at times some of the wood is heavier than water. A board foot of planed lumber (15/16 x 12 x 12 inches) will weigh about 4-3/4 pounds. This is roughly 30 percent heavier than oak.

Drying. The lumber will almost always be dried at the sawmill, rather than shipped green and dried in the U.S. In spite of this wood being so heavy, it reportedly dries without much difficulty. Shrinkage from green to 7 percent MC is only 4.6 percent tangentially (the width of a flatsawn piece of lumber) and 2.8 percent radially (the thickness of flatsawn lumber). These values are very low for a wood of this high density.

Gluing and Machining. The high density and some oiliness would make this wood somewhat difficult to glue with standard woodworking adhesives, but not as difficult as teak or other resinous woods. Surfaces should be prepared and glued within 15 minutes to achieve the best joint strength. It should not be necessary to clean the wood with a solvent before gluing in most cases, but for the strongest joint, this cleaning needs to be done.

It is reported to be moderately difficult to machine, as would be expected from its high density and its interlocked grain. Sharp tools and fresh sandpaper are essential for premium surfaces. Although it does not contain silica, nonetheless, tools seem to dull rapidly. The final machined surface has a high natural polish and luster.

Stability. For its density, the wood is exceptionally stable when exposed to humidity changes. It would take a 6 percent MC change to result in a 1 percent size change tangentially and 10 percent MC radially.

Strength. The ultimate strength (MOR) of this wood is 20,100 psi; the stiffness (MOE) is 2.4 million psi and the hardness is 2200 pounds. For comparison, red oak values are 14,300 psi, 1.8 million psi and 1,290 pounds.

Because of the density, all nails and screws must use pre-drilled holes (about 90 percent of the diameter of the fastener).

Color and Grain. Depending on the region where grown, Santos mahogany exhibits a range of color between light orange/brown with yellowish overtones to a dark reddish/purplish brown. Most of the lumber falls into the medium to dark orange/brown mahogany tone. There will be a slight muting of the color over time upon exposure to light. The interlocked grain gives a striped appearance especially on quartersawn grain, but not all pieces have heavy striping.

Overall, the grain is tight and fine textured with natural luster after machining and sanding.

Santos Mahogany has a strong scent when freshly cut. The scent quickly dissipates once it ages. However, this scent has been known to cause adverse respiratory reactions in some individuals. Therefore, avoid exposure to dust of this wood.

Lodgepole pine (Pinus contorta) grows in the Rocky Mountains, from Alaska to northern New Mexico, in the Black Hills and on the Pacific Coast. Poles of this tree were used by Native Americans for structural supports for teepees and lodges; hence the common name of lodgepole.

Lodgepole pine trees are not very large. In the Rockies, they may reach 80 feet in height, but seldom exceed 14 inches in diameter. Oftentimes, lodgepole pine lumber and ponderosa pine lumber are grouped together. They are similar in processing and properties. Both are moderately strong softwoods, making them ideal for construction.

A special characteristic of this wood is that the tangential surface (the wide face of a flatsawn piece of lumber) has a multitude of dimples. These show up especially when the lighting is at an low angle or when the wood is stained. Ponderosa has very few dimples.

Historically, lodgepole pine has been used for railroad ties, mine timber, log cabins, furniture and cabinets, and a myriad of local uses. Today, knotty pine paneling is an important use, as well as cabinetry and millwork. Local uses are important as well.

Processing suggestions and characteristics

Density
The density of lodgepole pine is about 29 pounds per cubic foot at 10 percent MC. This means that a dried piece of lumber 1 inch x 6 inch x 10 feet (actual size ¾ inch x 5-1/2 inch x 10 feet) will weigh 8 pounds. This is about 15 percent heavier than eastern white pine, but is similar to ponderosa pine.
 

Drying
Drying is rapid, but the small trees and presence of compression wood mean that warp is often a possibility. Weighting the pile tops in drying is helpful, as well as good stacking and rapid drying. Blue stain can occur quickly, so storage of logs and of sawn lumber before drying must be very short during warm weather. For this reason, most lodgepole pine lumber will be dried at
the sawmilling site.
 

Gluing and Machining

Gluing is fairly easy. Resin exudations will interfere with gluing if drying is not done hot enough. Machining is moderately good. Certainly sharp tools are suggested. Avoid drying under 9 percent MC at all costs, as drier wood machines poorly.
 

Stability
Lodgepole pine is a little more stable than many common species, requiring a 5 percent MC change or greater for a 1 percent size change in the width of flatsawn lumber, and 8 percent MC change in quartersawn stock.
 

Strength
The strength (MOR) of lodgepole is 9400 psi; the stiffness (MOE) is 1.34 million psi; and the hardness is 480 pounds. Corresponding eastern white pine values are 8600 psi, 1.24 million psi, and 380 pounds. In other words, it is stronger, stiffer and harder than EWP. Ponderosa values are nearly identical (9400 psi, 1.29 million psi, and 460 pounds).

Color and Grain
The wood is straight grained, has a medium to fine texture and has pronounced dimples on the split, tangential surface.

The sapwood of lodgepole pine is nearly white to a pale yellow, while the heartwood is light yellow to a yellowish brown. In dried lumber, the sapwood and heartwood are not easily separated from each other.

Lodgepole pine has a pleasant resinous odor. Some people may find that pine dust and the aroma cause allergic reactions.