Introduction to Andok
Andok (Irvingia gabonensis) is an African hardwood known for its considerable mass, strength, and local utility. While not common on the international commercial timber market, it sees widespread use locally across various heavy-duty structural and joinery roles. According to the technical sheet published by CIRAD Tropix, Andok presents an exceptional set of mechanical properties alongside distinct physical challenges. For woodworkers and resin table makers evaluating live-edge slabs or sawn boards of this species, understanding its behavior during drying, machining, and epoxy adhesion is essential.
Visual Characteristics and Log Dimensions
Logs of Irvingia gabonensis typically range from 60 to 100 cm in diameter, offering viable widths for medium to large tabletop sections and river builds. Sawn lumber has a medium texture with straight or slightly interlocked grain. The general color reference is brown, but the wood displays nuance: the sapwood is not demarcated yet appears yellow with red stripes, while the heartwood ranges from pale green-brown to orange-yellow before fading with age to grey-brown.
Density, Hardness, and Mechanical Strength
Andok is a remarkably heavy and dense timber. At 12% moisture content, it has an average specific gravity of 0.93, translating to a weight of about 58.1 lb/ft³. In the shop, a standard 2-inch-thick tabletop slab weighs approximately 9.7 lb per square foot before casting.
On the French Monnin hardness scale—where higher numbers indicate harder timber—Andok registers at 6.8 at 12% moisture content. (Note that Monnin hardness is an entirely different test method from the American Janka scale and should never be converted directly to Janka values.) This level of hardness delivers great resistance to indentation and impact, which aligns with its high static bending strength of 140 MPa (about 20,310 psi) and crushing strength of 76 MPa (about 11,020 psi). Its modulus of elasticity is listed at 25,060 MPa (about 3,635,000 psi), reflecting a very rigid material.
| Property | CIRAD Tropix value | What it means / US units |
|---|---|---|
| Botanical name(s) | Irvingia gabonensis | |
| Colour / texture / grain | Brown; texture medium; grain straight or interlocked; interlocked grain slight | |
| Specific gravity (12% MC) | 0.93 | about 58.1 lb/ft³; a 2-inch-thick slab weighs about 9.7 lb per sq ft |
| Monnin hardness (12% MC) | 6.8 | French hardness scale; higher = harder (not a Janka value) |
| Total tangential shrinkage | 11.2 % | green to oven-dry |
| Total radial shrinkage | 6.6 % | green to oven-dry |
| Ratio St/Sr | 1.7 | closer to 1 = less cupping tendency |
| Coefficient of volumetric shrinkage | 0.63 % per % MC | volume change per 1% change in moisture content |
| Fibre saturation point | 28 % | |
| Thermal conductivity | 0.30 W/(m·K) | |
| Crushing strength (12% MC) | 76 MPa | about 11,020 psi |
| Static bending strength (12% MC) | 140 MPa | about 20,310 psi |
| Modulus of elasticity (12% MC) | 25,060 MPa | about 3,635,000 psi |
| Decay (fungi) resistance | Durability class 2 – durable | |
| Termite resistance | Class M – moderately durable | |
| Dry-wood borer resistance | Class S – susceptible (risk in all the wood) | |
| Heartwood treatability | Class 3-4 – poorly or not permeable | |
| Use class from natural durability | Class 3 – not in ground contact, outside | |
| Drying | rate slow; distortion: high risk; checking: high risk; collapse: no known specific risk; casehardening: no known specific risk | |
| Suggested kiln program temperatures | 45–65 °C | about 113–149 °F |
| Machining | blunting fairly high; saw teeth: stellite-tipped; cutting tools: tungsten carbide | |
| Nailing and screwing | Good but pre-boring necessary | |
| 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, Movement, and the Epoxy Interface
When bonding timber to cured epoxy resin, dimensional stability is a primary consideration. Andok exhibits substantial movement from green to oven-dry conditions:
- Total tangential shrinkage: 11.2 %
- Total radial shrinkage: 6.6 %
- Ratio (St/Sr): 1.7
- Coefficient of volumetric shrinkage: 0.63 % per % MC
- Fibre saturation point: 28 %
A coefficient of volumetric shrinkage of 0.63 % per 1% moisture change means Andok expands and contracts significantly when ambient relative humidity fluctuates. Coupled with a 1.7 shrinkage ratio, slabs will have a moderate tendency to cup or twist if moisture is uneven. In an epoxy river table, substantial wood movement places heavy shearing forces on the epoxy bond-line. Builders must ensure the wood is fully conditioned to indoor equilibrium before pouring and apply a balanced finish across all faces to slow moisture exchange.
Drying Behavior and Kiln Risks
CIRAD Tropix rates the drying rate of Andok as slow. The timber carries a high risk of distortion and a high risk of checking during seasoning. On the other hand, it has no known specific risk of collapse or casehardening. Kiln drying schedules generally run through mild temperatures between 45 °C and 65 °C (about 113 °F to 149 °F). Because thick slabs take a long time to lose free and bound water, drying cannot be rushed without triggering severe surface splits or deep checks.
Machining, Fastening, and Gluing
Due to its high density, Andok causes a fairly high blunting effect on tools. CIRAD Tropix advises using stellite-tipped saw teeth and tungsten carbide cutting knives to maintain clean cuts and avoid tearout, particularly where slight interlocked grain is present. For joinery and mounting to table bases, nailing and screwing properties are good, but pre-boring is strictly necessary to prevent splitting.
Regarding assembly, the CIRAD sheet highlights that due to Andok’s high specific gravity, gluing must be performed strictly in compliance with proper code of practice. Because the heartwood has poor to no permeability (treatability class 3-4), resin and seal coats do not soak deeply into the pores. Thorough surface preparation, scuff sanding, and complete dust removal are mandatory before applying any epoxy seal coat or river pour.
Durability and CITES Status
Andok heartwood is classified as Durability class 2 (durable) against wood-decay fungi and Class M (moderately durable) against termites. However, it is rated Class S (susceptible) to dry-wood borers, with the risk present throughout all the wood. In terms of trade regulations, Irvingia gabonensis is not listed in the CITES Appendices (Washington Convention 2025). Traditional end-uses include heavy carpentry, flooring, industrial or heavy flooring, decking, exterior and interior joinery, tool handles, turned goods, ship building, vehicle flooring, boxes, crates, pallets, and wood frame housing.
Is It a Good Epoxy Table Wood?
Andok can yield a very tough, wear-resistant tabletop, but it is a demanding species for epoxy river builds. Its high shrinkage values (11.2% tangential) and strong volumetric movement create high internal stresses along the wood-epoxy interface if indoor humidity swings. Furthermore, its high risk of checking during drying and its heavy tool blunting require careful preparation. If you use Andok, ensure the slab is completely dry, use carbide tooling, pre-bore every mechanical fastener, and adhere closely to proper surface preparation practices before pouring resin.
Sources
Published October 31, 2026. Sources are linked in the text.
Header image: original graphic by BigEpoxy.com.
Staff note: Because CIRAD Tropix rates Irvingia gabonensis as poorly or not permeable (class 3-4) and susceptible to dry-wood borers (class S risk in all the wood), any preventative borer treatments or penetrating sealers will meet substantial resistance entering the dense heartwood. (Source: CIRAD Tropix 7 technical sheet: Andok.)