J and C Lumber >  Cumaru

Cumaru

Cumaru wood sample

Uses:

Heavy construction, cogs and shafts, barge and dock fenders, flooring, railroad crossties, pulp mill equipment, tool handles, bearings, turnery. A substitute for lignum vitae.

Dipteryx odorata

Family: Leguminosae
Tonka
Ebo

Cumaru (Brazil)

Other Common Names:

Almendro (Costa Rica, Panama), Sarrapia (Venezuela, Colombia), Charapilla, Cumarut (Peru).

Distribution:

The Guianas, Venezuela, Colombia, and the Amazon region of Brazil; reaches its best development on well-drained gravelly or sandy sites. Cultivated in many areas for the tonka beans used as a flavoring.

The Tree:

A large overstory tree sometimes to 160 ft in height and trunk diameters to 40 in.; unbuttressed cylindrical boles are generally clear to 60 to 80 ft.

The Wood:

General Characteristics:

Heartwood: Fresh heartwood is reddish brown or purplish brown with light yellowish-brown or purplish streaks; upon exposure gradually' becomes uniform light brown or yellowish brown;

Sapwood: distinct, narrow, yellowish brown;

Grain: interlocked;

Texture: fine;

Luster: rather low to medium;

Odor and taste: taste not distinctive but may have a vanilla-like or rancid odor.

Appearance and feel: waxy or oily feel;

Mechanical Properties:

(First set of data based on the 2-in. standard; second set on the 1-in. standard.)
Moisture content
(%)
Bending strength
(psi)
Modulus of elasticity
(1,000 psi)
Maximum crushing strength
(psi)
Janka side hardness 2200 lb for green material and 3,540 lb at 12% moisture content. Forest Products Laboratory toughness average for green and dry material is 265 in.-lb. (5/8-in. specimen).
12% 27,2703,03013,720
Green (74)19,2902,6909,020
12% (24)22,4003,01013,200

Drying and Shrinkage:

The wood is rated as easy to air-season with a slight tendency to check and with moderate warping; drying was uniformly rapid. No dry kiln data available. Shrinkage from green to ovendry: radial 5.0%; tangential 7.6%; volumetric 12.0%.

Working Properties:

The wood is difficult to saw and bore; where severely interlocked grain is not present, the wood planes to a smooth surface. Because of its high density and oily nature, the wood glues poorly.

Durability:

The timbers have a reputation for being very durable. Laboratory tests also show the heartwood to be very durable in resistance to both brown-rot and white rot fungi. The wood has excellent weathering characteristics.

Preservation:

Heartwood absorption and penetration of treating solutions using both open-tank and pressure-vacuum systems are inadequate. Sapwood is reported to treat well, particularly with a high end-grain exposure.

Additional Reading: (24), (46), (56), (74)

56. Record, S. J., and R. W. Hess. 1949. Timbers of the new world. Yale University Press, New Haven, Conn.

From: Chudnoff, Martin. 1984. Tropical Timbers of the World. USDA Forest Service. Ag. Handbook No. 607.

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