Handling & safety. Reported to cause skin irritation in some people (severe reactions uncommon).
Properties
| Latin name | Ochroma pyramidale |
|---|---|
| Species type | Hardwood |
| Origin | Tropical regions of the Americas; also grown on plantations. |
| Janka hardness | 300 N |
| Modulus of rupture | 19.6 MPa |
| Elastic modulus | 3.71 GPa |
| Crushing strength | 11.6 MPa |
| Specific gravity | 0.15 |
| Porosity | Diffuse-porous |
| Movement class | Very low |
| Tangential shrinkage | 6% |
| Radial shrinkage | 2.3% |
| Volumetric shrinkage | 8.5% |
| T/R ratio | 2.6 |
| Durability (EN 350) | Class 5 |
| Relative cost | Budget |
Density and mechanical properties are typical values at around 12% moisture content. Shrinkage figures represent total dimensional change from fibre saturation to oven dry. Individual boards vary.
Working the timber
Very easy to machine with minimal dulling, but can develop fuzzy surfaces with dull cutters. Poor nail/screw holding; glue joints are preferred. Takes stain/finish well but can soak up a lot of finish on first coats.
Finishing & gluing
Stains and finishes well, but tends to absorb a lot of finish initially—plan for sealing/extra coats.
Generally glues well; glue is preferred over mechanical fasteners due to poor fastener-holding.