Cumaru

Scientific name: Dipterix spp

Geographic origin: Central America and north of the Amazone.

Description

  • Sapwood: white yellowish.
  • Heartwood: brown yellowish to brown redish.
  • Fiber: straight, usually quite cross.
  • Grain: medium size.

Capacity of being impregnated

  • Sapwood: medium capacity of being impregnated.
  • Heartwood: low capacity of being impregnated.

Mechanization

  • Sawing process: difficult due to its hardness and its silica content, high power saws are required.
  • Drying process: very slow. Little risk of cimentation. High risk of crack formation and lower risk of deformations.
  • Planing process: difficult due to its hardness, risk of generalized risk of repelling due to its intertwined fibers pieces. Slow mechanisation is highly recommended.
  • Gluing process: difficulties can arise due to its tannin contents.
  • Nailing and screwing process: difficulties due to its hardness. Pre-drilling is required.
  • Finish: a thorough sanding is required due to the risk of repelling.

Physical properties

  • Apparent density at 12% humidity 1,020 kg/m3 very heavy wood.
  • Dimensional stability
  • - Volumetric contraction coefficient 0.49 % nervous wood.
  • - Relation between contractions 1.4% no tendency to deformity.
  • Hardness (Chaláis-Meudon) 11.0 very hard wood .

Cumaru

Mechanical properties

  • Resistance to static flexion 1.780 kg/cm2.
  • Elasticity module 220,000 kg/cm2.
  • Resistance to parallel compression 680 kg/cm2.

Cumaru

Observations

It is the South American wood that is more similar to the African Talí-Elondo. This wood is highly recommened for exterior deck and it is a good substitute to Ipe wood.