Woods to Know: Desert Ironwood | Canadian Woodworking & Home Improvement

Woods to Know: Desert Ironwood

Desert Ironwood (Olneya tesota)

by Peter MacSween

I have to admit I've never seen a real piece of Desert Ironwood and it's not that I haven't tried.  I've seen pictures of it and they only serve to whet the appetite. Desert Ironwood can be a very beautiful wood, multicoloured with a distinctive grain pattern. It is also hard to source and only comes in small pieces for turning and carving.  With that scarcity comes a high cost, comparable to rare imported species.

Desert Ironwood is a small tree, typically 20 to 30 feet tall with trunk diameters of 1 to 2 feet.  It is extremely slow growing with a long lifespan. Trees over 800 years old have been found, and it is speculated that there are individuals over 1000 years old. The slow growth is probably due to adaptations to preserve water consumption. Slow growth rates also yield a very dense wood.  It is so heavy that it will sink in water.

WTK_desert-ironwood

Desert Ironwood is endemic to the Sonoran Desert of the American southwest and the Mexican northwest. It grows nowhere else. Within its range, it is an extremely important specie ecologically.  It is considered a nurse species for other plants providing shelter from the extreme heat as well as from deadly frosts. Animals are also dependent on it for food and shelter. It is reported that over 500 plant and animal species are associated with the Desert Ironwood tree.

Wood from the Desert Ironwood is usually very attractive. The heartwood can contain orange and yellow hues as well as darker reds and browns. There are often purple and black streaks throughout. The sharply demarcated sapwood is a thin orange band. The grain can be quite wild and is also very finely textured.  The best pieces have an active swirling appearance.

Working with Desert Ironwood is difficult. It quickly dulls tools; expect to make many trips to the sharpening stone.The small sizes available means it will have to be worked mostly by hand.  It turns well, holding detail and possessing a natural luster when polished.

WTK_desert-ironwood-endgrain
Desert Ironwood end-grain

The wood was first commercially used for iconic carvings produced by people living near the Sonoran Desert. At first, only dead material was used.  Increasing demand for the carvings led to over exploitation. The trees slow growth makes recovery and repopulation a lengthy process so Desert Ironwood is protected in Mexico. Today it is considered one of the finest woods for knife and gun scales and handles. The pieces available are typically very small although small logs are reported to be available. Expect a lot of waste and degrade in the logs.

Desert Ironwood is a rare species, and most woodworkers will only be able to obtain it from wood dealers in the United States. Obtaining it will lighten your wallet considerably. If you are a knife maker you will probably want to obtain some. I would like to have a small piece for my collection, but I am not holding my breath!  Until then, I will have to be satisfied with the many images available in print or online.
 
 
Average Dried Weight75 lbs/ft³A measure of its weight at 12% moisture and an ambient temperature of 70°F.
Specific Gravity1.21A measure of the ratio of its density compared to water (at 12% MC)
ShrinkageRadial: n.a.
Tangential: n.a.
Volumetric: n.a.
Radial (the amount of crosswise shrinkage);
Tangential (the amount of lengthwise shrinkage);
Volumetric (the total amount of shrinkage.)
T/R Ration.a.A measure of the uniformity of tangential to radial shrinkage.
Janka Hardness3,260 lbfA measure of resistance to denting and abrasion.
Crushing Strengthn.a.A measure of compression strength parallel to the grain.
Colour
Heartwood color ranges from an orangish yellow to a darker red or brown, with darker violet to black streaks. Some pieces may be almost entirely black. Narrow yellow sapwood is clearly demarcated from heartwood.
GrainWild or gnarled.
TextureFine, even.
Workability
Very difficult to work on account of its density. High cutting resistance. Desert Ironwood is usually restricted to very small projects, though it takes a good natural polish and is very stable in service. Turns, polishes, and finishes well.
Uses
Knife handles, carvings, and turned objects.
PriceSupplies can be erratic. Check with your local dealer.
Dealer Locator
 
  
Photos and Specifications Courtesy of: The Wood Database
 
 
Average Dried Weight31-53 lbs/ft³A measure of its weight at 12% moisture and an ambient temperature of 70°F.
Specific Gravity.50-.85A measure of the ratio of its density compared to water (at 12% MC)
ShrinkageDiameter: 10-16%
Wall Thickness: 15-7%

 
Radial (the amount of crosswise shrinkage);
Tangential (the amount of lengthwise shrinkage);
Volumetric (the total amount of shrinkage.)
Janka Hardness960 lbfA measure of resistance to denting and abrasion.
Crushing Strength1,410-1,610 lbf/in2A measure of compression strength parallel to the grain.
Colour
Generally a uniform and pale yellow to almost white. Live bamboo that has been left standing too long frequently develops fungal decay, discoloring the wood with brown or black streaks and patches.
GrainBeing a monocot in the grass family, bamboo does not have any sapwood/heartwood or growth rings.
TextureTexture is very uniform, and ranges from medium to fine depending on density. Bamboo that has been split and processed into lumber will have intermittent variations in the fiber at each node on the stem.
Workability
By woodworking standards, bamboo can be different. It is not necessarily difficult to work with, but depending on the species, it may require some special care. Bamboo fibers tend to split and pull out when being cross-cut, (applying masking tape across the cut line beforehand is recommended to prevent this sort of tearout). Carbide cutters are strongly recommended, and surface sanding is suggested instead of thickness planing with steel cutters, both for longevity of cutting edges, and quality of the finished surface. Bamboo glues, stains, and finishes well. When turning giant bamboo species, tools dull quickly, and endgrain tearout is common, but tearout tends to be very shallow, and the endgrain sands nearly as easily as the facegrain, and an overall smooth finish can be achieved with minimal effort.
Uses
Veneer, paper, flooring, fishing rods, ladders, scaffolding, musical instruments (flutes/woodwinds/chimes), furniture, window blinds, carving, turned items, and small novelty items.
Price$354.75 - 4' x 8' Solid laminated Moso
$265.00 - 4' x 8' 3/4" Plywood sheets
 
  
Photos and Specifications Courtesy of: The Wood Database