Introduction to Tchitola for Epoxy Tabletops
Tchitola, botanically classified under Oxystigma mannii, Oxystigma oxyphyllum, and the synonym Pterygopodium oxyphyllum, is an African hardwood hailing from countries such as Angola, Cameroon, Republic of the Congo, Democratic Republic of the Congo, Gabon, and Nigeria. For builders considering custom epoxy river tables or wood-and-epoxy tabletops, Tchitola offers distinctive aesthetics paired with specific working traits documented by wood researchers.
According to technical data published in the CIRAD Tropix sheet, the wood features a copper red brown heartwood highlighted by blackish veins and blackish resin exudation. The sapwood is clearly demarcated from the heartwood and typically measures from 6 to 10 cm thick. Logs generally range from 70 to 120 cm in diameter. With a coarse texture and grain that is straight or slightly interlocked, wood from less resinous logs can serve as an attractive substitute for walnut (Juglans spp.).
Weight, Density, and Hardness
Tchitola falls into a moderate-density category among tropical hardwoods. It has an average specific gravity of 0.64 at 12% moisture content, which equates to a density of about 40.0 lb/ft³. In the shop, this means a 2-inch-thick slab weighs roughly 6.7 lb per square foot before pouring resin. This provides sufficient mass for a solid tabletop without making the piece unmanageable to maneuver or assemble on a base.
Hardness is measured using the French Monnin scale, where Tchitola scores an average of 2.9 at 12% moisture content. It is important to remember that the Monnin scale is distinct from the Janka scale; on the Monnin index, higher numbers indicate harder wood, but the values cannot be directly converted to Janka pounds. Mechanically, Tchitola demonstrates a crushing strength of 58 MPa (about 8,410 psi), a static bending strength of 88 MPa (about 12,760 psi), and a modulus of elasticity of 14,960 MPa (about 2,170,000 psi), providing substantial structural rigidity for broad tabletop spans.
| Property | CIRAD Tropix value | What it means / US units |
|---|---|---|
| Botanical name(s) | Oxystigma mannii, Oxystigma oxyphyllum, Pterygopodium oxyphyllum (synonymous) | |
| Colour / texture / grain | Red brown; texture coarse; grain straight or interlocked; interlocked grain slight | |
| Specific gravity (12% MC) | 0.64 | about 40.0 lb/ft³; a 2-inch-thick slab weighs about 6.7 lb per sq ft |
| Monnin hardness (12% MC) | 2.9 | French hardness scale; higher = harder (not a Janka value) |
| Total tangential shrinkage | 7.5 % | green to oven-dry |
| Total radial shrinkage | 3.9 % | green to oven-dry |
| Ratio St/Sr | 1.9 | closer to 1 = less cupping tendency |
| Coefficient of volumetric shrinkage | 0.45 % per % MC | volume change per 1% change in moisture content |
| Fibre saturation point | 28 % | |
| Thermal conductivity | 0.22 W/(m·K) | |
| Crushing strength (12% MC) | 58 MPa | about 8,410 psi |
| Static bending strength (12% MC) | 88 MPa | about 12,760 psi |
| Modulus of elasticity (12% MC) | 14,960 MPa | about 2,170,000 psi |
| Decay (fungi) resistance | Durability class 3 – moderately durable | |
| Termite resistance | Class M – moderately durable | |
| Dry-wood borer resistance | Class D – durable (sapwood demarcated, risk limited | |
| Heartwood treatability | Class 3-4 – poorly or not permeable | |
| Use class from natural durability | Class 2 – inside or under cover (dampness possible) | |
| Drying | rate normal; distortion: slight risk; checking: slight risk; collapse: no known specific risk; casehardening: no known specific risk | |
| Suggested kiln program temperatures | 53–62 °C | about 127–144 °F |
| Machining | blunting normal; saw teeth: ordinary or alloy steel; cutting tools: ordinary | |
| Nailing and screwing | Good | |
| CITES status | This species is not listed in the CITES Appendices (Washington Convention 2025). |
Values from the CIRAD Tropix technical sheet (average values for mature wood, 12% moisture content where noted). US-unit conversions are calculated by BigEpoxy (1 MPa = 145.04 psi; density = specific gravity × 62.43 lb/ft³).
Shrinkage, Stability, and Epoxy Interface Behavior
Whenever wood is bonded directly to a cured resin river, dimensional stability across moisture fluctuations is a primary engineering concern. Tchitola exhibits a total tangential shrinkage of 7.5% and a total radial shrinkage of 3.9% from green to oven-dry conditions, resulting in a tangential-to-radial shrinkage ratio (St/Sr) of 1.9. Its fibre saturation point is 28%, and its coefficient of volumetric shrinkage is 0.45% per 1% change in moisture content.
An St/Sr ratio of 1.9 is moderate. While tangential movement is roughly double the radial movement, proper kiln drying down to service moisture levels will minimize the risk of severe cupping. However, because resin does not shrink or swell with humidity, the wood must be thoroughly conditioned before casting to prevent internal stresses or hairline fractures along the glue line.
Drying Characteristics and Defects
The CIRAD Tropix technical sheet reports a normal drying rate for Tchitola. Kiln-drying schedules for mature wood typically span temperatures from 53 to 62 °C (about 127 to 144 °F). During seasoning, there is only a slight risk of distortion and a slight risk of checking. Furthermore, CIRAD records no known specific risk of casehardening and no known specific risk of cellular collapse. These mild drying risks make the material relatively straightforward to bring down to uniform indoor equilibrium moisture content.
Machining, Resin Exudation, and Bonding
When working Tchitola with shop equipment, blunting of cutting edges is normal, and standard cutting tools or saw teeth made from ordinary or alloy steel perform well. Nailing and screwing properties are rated as good. However, Tchitola has two critical handling considerations:
- Resin Clogging and Glue Adhesion: The wood produces blackish resin exudations. This natural resin tends to clog blades and tooling. More importantly, CIRAD Tropix explicitly notes that resin exudations must be taken into account when gluing. In an epoxy build, oily or resinous deposits on mating edges can disrupt mechanical adhesion. Surfaces intended for the epoxy river must be properly degreased and prepared in strict accordance with the epoxy resin manufacturer’s technical data sheet.
- Health and Safety: The sawdust from Tchitola is known to be an irritant, requiring reliable dust extraction and respiratory protection during surfacing.
Natural Durability and CITES Status
For interior use, Tchitola provides reliable natural resistance. The heartwood is classified as Durability class 3 (moderately durable) against xylophagous fungi, Class M (moderately durable) against termites, and Class D (durable) against dry-wood borers, with borer risks limited strictly to the sapwood. Its natural durability aligns with Use Class 2 (inside or under cover, where dampness is possible). Heartwood treatability is rated Class 3-4, meaning it is poorly or not permeable to chemical preservatives.
Regarding international trade regulations, Tchitola is not listed in the CITES Appendices (Washington Convention 2025). Its recognized industrial end-uses range widely, including current furniture, interior and exterior joinery, sliced veneer, glued laminated components, and carpentry.
Is It a Good Epoxy Table Wood?
Tchitola can make a striking epoxy river table thanks to its copper red-brown heartwood and contrasting dark veins. Its low risk of distortion and collapse during drying, paired with solid mechanical strength, offers reliable structural behavior. However, its natural resin exudations demand careful attention. Resin buildup can foul tooling and interfere with epoxy bonding along live edges, requiring meticulous solvent degreasing and surface prep prior to the pour. For builders prepared to manage resinous wood surfaces, Tchitola serves as a stable, handsome walnut alternative.
Sources
Published October 30, 2026. Sources are linked in the text.
Header image: original graphic by BigEpoxy.com.
Staff note: CIRAD Tropix notes that Tchitola sawdust is an irritant and the wood’s resin tends to clog tooling, making aggressive dust collection and frequent blade cleanings important in the shop. (Source: CIRAD Tropix 7 technical sheet: Tchitola.)