Antiaris Wood in Epoxy River Tables: Buyer & Builder Guide
Antiaris (known botanically as Antiaris toxicaria, with synonyms Antiaris africana and Antiaris welwitschii) is an African hardwood species documented in the CIRAD Tropix technical sheet. For makers designing custom epoxy river tables or wood-and-epoxy tabletops, understanding the physical and mechanical properties of Antiaris is essential to prevent warping, bond line failure, or surface damage.
Appearance, Figure, and Slab Potential
Antiaris exhibits a light yellow color, with heartwood ranging from cream white to light yellow. The sapwood is not demarcated from the heartwood, giving boards and live-edge slabs a consistent, uniform visual tone across the width. The wood presents a medium texture with interlocked grain, noted specifically as slight interlocked grain. In raw log form, Antiaris reaches diameters from 70 to 120 cm, offering substantial width potential for wide single-slab designs or twin live-edge river tabletop configurations.
Weight and Surface Hardness
Antiaris is a lightweight to medium-density timber. At 12% moisture content, it has an average specific gravity of 0.47, corresponding to an air-dry density of about 29.3 lb/ft³. A 2-inch-thick tabletop slab weighs approximately 4.9 lb per square foot, making large river tables relatively easy to transport and assemble compared to denser hardwoods.
Surface hardness is measured on the Monnin scale, a French testing metric where higher numbers indicate greater resistance to indentation (this is not a Janka value and must not be treated as one). Antiaris registers a Monnin hardness of 1.5 at 12% moisture content. This low rating indicates a soft surface prone to denting, meaning tabletop applications will benefit from protective topcoats or perimeter epoxy encapsulation.
Dimensional Movement Beside Epoxy Rivers
When bonding timber directly to rigid epoxy casting resins, wood movement dictates the integrity of the river interface. Antiaris exhibits a total tangential shrinkage of 6.9% and a total radial shrinkage of 4.0% from green to oven-dry conditions, yielding an St/Sr ratio of 1.7. Its coefficient of volumetric shrinkage is 0.39% per 1% change in moisture content, with a fiber saturation point at 35%.
Because the St/Sr ratio is 1.7, flat-sawn boards show moderate tendency toward cupping. Combined with a volumetric coefficient of 0.39%, the wood will expand and contract moderately with indoor humidity swings. To avoid seam separation or stress cracking along the epoxy river bond, slabs must be thoroughly acclimated to indoor equilibrium moisture content before casting.
Drying Behavior and Risks
The drying rate for Antiaris is classified as normal, with slight risk of surface checking and no known specific risk of collapse or casehardening. However, CIRAD identifies a high risk of distortion during drying, as well as risks of end checks in thick material. Kiln drying programs typically operate between 60 °C and 70 °C (140 °F to 158 °F). Thick live-edge slabs require strict end-grain sealing and careful restraint to mitigate cupping, twisting, or end splitting before machining.
Machining, Fastening, and Durability
Antiaris machines smoothly in the shop. It presents normal blunting effects on cutting tools, and cutting edges made of ordinary tools or ordinary or alloy steel saw teeth perform satisfactorily. Nailing and screwing properties are rated good, ensuring reliable mechanical connection to table bases and substructures.
In terms of natural durability, Antiaris falls into Durability class 5 (not durable) against wood-decay fungi. It is rated Class S (susceptible) to termites and dry-wood borers throughout all the wood. As a result, its natural durability limits it strictly to Use Class 1 (inside, no dampness). In case of temporary humidification, it requires preservative treatment, and CIRAD notes that use in permanent humidification is not recommended.
| Property | CIRAD Tropix value | What it means / US units |
|---|---|---|
| Botanical name(s) | Antiaris toxicaria, Antiaris africana (synonymous), Antiaris welwitschii (synonymous) | |
| Colour / texture / grain | Light yellow; texture medium; grain interlocked; interlocked grain slight | |
| Specific gravity (12% MC) | 0.47 | about 29.3 lb/ft³; a 2-inch-thick slab weighs about 4.9 lb per sq ft |
| Monnin hardness (12% MC) | 1.5 | French hardness scale; higher = harder (not a Janka value) |
| Total tangential shrinkage | 6.9 % | green to oven-dry |
| Total radial shrinkage | 4.0 % | green to oven-dry |
| Ratio St/Sr | 1.7 | closer to 1 = less cupping tendency |
| Coefficient of volumetric shrinkage | 0.39 % per % MC | volume change per 1% change in moisture content |
| Fibre saturation point | 35 % | |
| Thermal conductivity | 0.17 W/(m·K) | |
| Crushing strength (12% MC) | 36 MPa | about 5,220 psi |
| Static bending strength (12% MC) | 58 MPa | about 8,410 psi |
| Modulus of elasticity (12% MC) | 9,000 MPa | about 1,305,000 psi |
| Decay (fungi) resistance | Durability class 5 – not durable | |
| Termite resistance | Class S – susceptible | |
| Dry-wood borer resistance | Class S – susceptible (risk in all the wood) | |
| Heartwood treatability | Class 1 – easily permeable | |
| Use class from natural durability | Class 1 – inside (no dampness) | |
| Drying | rate normal; distortion: high risk; checking: slight risk; collapse: no known specific risk; casehardening: no known specific risk | |
| Suggested kiln program temperatures | 60–70 °C | about 140–158 °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).
Frequently Asked Questions
What does Antiaris look like when paired with tinted epoxy?
Antiaris features a cream white to light yellow heartwood with undemarcated sapwood and slight interlocked grain. Its pale, warm hue provides an understated backdrop that pairs cleanly with deep ocean blue, emerald, or smoky black epoxy river pours.
Is Antiaris hard enough for high-traffic dining tables?
Antiaris has a Monnin hardness value of 1.5, which represents a soft hardwood. While adequate for light-duty furniture or decorative tops, high-traffic dining surfaces require careful handling to prevent scratching, or a durable protective surface film over the timber.
Can Antiaris epoxy tables be placed on an outdoor patio?
No. Natural durability ratings place Antiaris in Durability class 5 (not durable against fungi) and Class S for termites and borers, restricting it to Class 1 indoor environments with no dampness. Outdoor weather exposure will lead to rapid fungal and insect decay.
What should builders watch for when preparing Antiaris slabs?
Drying distortion is listed as a high risk, and thick slabs carry a risk of end checks. Builders must ensure lumber is dried flat under restraint, sealed on the end grain, and verified for stable moisture levels before pouring epoxy.
Is Antiaris restricted under international trade agreements?
According to the CIRAD Tropix technical sheet, Antiaris is not listed in the CITES Appendices (Washington Convention 2025), allowing it to be bought and traded without CITES export permit controls.
What mechanical strengths does Antiaris offer for table bases?
At 12% moisture content, Antiaris has a crushing strength of 36 MPa (about 5,220 psi), static bending strength of 58 MPa (about 8,410 psi), and a modulus of elasticity of 9,000 MPa (about 1,305,000 psi), providing moderate structural rigidity for table construction.
Sources
Published October 31, 2026. Sources are linked in the text.
Header image: original graphic by BigEpoxy.com.
Staff note: Antiaris heartwood is classified as Class 1 (easily permeable) for treatability, meaning it absorbs liquid preservatives, deep-penetrating stabilizing agents, and low-viscosity resin sealers far more readily than typical tropical hardwoods. (Source: CIRAD Tropix 7 technical sheet: Antiaris.)