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.