Working with Obeche in Custom Epoxy Tables
Obeche (Triplochiton scleroxylon) is a west-central African hardwood prized for its creamy white to pale yellow color and uniform medium to coarse texture. Because there is little to no color contrast between sapwood and heartwood, obeche offers a clean, light backdrop that contrasts sharply with colored or transparent resin pours. Mature trees reach a height of 50 m (150 ft) or more and can achieve a diameter of up to 2 m (5 ft), producing exceptionally large, clear boards with straight or interlocked grain.
Obeche Physical and Shrinkage Properties
Understanding wood stability and density is essential before encapsulating boards in resin. The following data highlights the physical characteristics of obeche compiled by the Forest Products Laboratory.
| Property | Measurement / Unit |
|---|---|
| Tree Height | 50 m (150 ft) or more |
| Trunk Diameter | Up to 2 m (5 ft) |
| Air-Dry Weight (Density) | 385 kg m–3 (24 lb ft–3) |
| Radial Shrinkage (Green to Ovendry) | 3.0% |
| Tangential Shrinkage (Green to Ovendry) | 5.4% |
| Volumetric Shrinkage (Green to Ovendry) | 9.2% |
Shrinkage Behavior and Dimensional Stability
Wood naturally expands and contracts across its dimensions as relative humidity fluctuates. In obeche, tangential shrinkage (5.4%) is nearly double radial shrinkage (3.0%). This ratio means that flatsawn boards will experience significantly more width-wise movement than quartersawn boards when environmental moisture changes.
For epoxy river tables, raw slabs must always be dried to a stable moisture content before casting. Encapsulating wood with unstable moisture levels invites internal stresses, potentially resulting in warping or delamination along the epoxy-wood bondline. Because obeche dries readily with little degrade, reaching target moisture levels is generally manageable without severe cracking.
Epoxy Table Considerations for Obeche
When engineering a custom river table or resin-infused tabletop with obeche, keep the following fabrication factors in mind:
- Porosity and Seal Coats: Obeche features a medium to coarse texture. Applying a qualitative seal coat prior to the main pour is essential to close the pores and prevent trapped air from venting into the curing resin as bubbles.
- Bonding and Gluing: Obeche is documented to glue and machine well. This workability helps resin achieve a reliable mechanical bond along live edges and straight cuts.
- Dent Resistance and Protection: Obeche is fairly soft. Because harder woods naturally resist dents and everyday surface wear much better, an obeche tabletop benefits from a durable surface finish or an overall flood coat to safeguard the soft fibers from impact.
- Tabletop Weight: With an air-dry weight of 385 kg m–3 (24 lb ft–3), obeche is relatively lightweight compared to dense tropical hardwoods, making wide river tables easier to handle and mount.
- Allowing for Natural Movement: Always mount obeche tops to table bases using slotted fasteners, giving the wood freedom to expand and contract across its tangential dimension without cracking around rigid mechanical fixings.
Sources
USDA Wood Handbook (FPL-GTR-282)
Published October 28, 2026. Sources are linked in the text.
Header image: original graphic by BigEpoxy.com.
Staff note: When inspecting raw stock for an epoxy project, verify that the lumber is clean and bright; the USDA Wood Handbook (FPL-GTR-282) notes that obeche is not resistant to decay and its green sapwood is particularly susceptible to blue stain if not promptly dried.