Visual Character and Slab Appearance
Ayan (Distemonanthus benthamianus), also referenced by the trade names Distemonanthus and Movingui, originates from Africa. Sawn heartwood displays an eye-catching lemon-yellow to yellow-brown color. The sapwood is clearly demarcated from the heartwood, measuring between 2 to 4 cm thick, which provides a clean visual boundary if you preserve live edges inside an epoxy river void.
The wood features a medium texture with interlocked grain that the CIRAD Tropix technical sheet rates as slight. Some logs display a highly figured wood pattern that adds strong visual depth under clear flood coats. However, woodworkers inspecting raw material should be vigilant: the data sheet notes the possible presence of internal stresses and wind shakes in logs, which must be examined before laying out river table channels.
Density, Hardness, and Structural Strength
Ayan is a moderately heavy, stout hardwood with a specific gravity of 0.73 at 12% moisture content. In workshop terms, that translates to approximately 45.6 lb/ft³, meaning a 2-inch-thick tabletop slab weighs about 7.6 lb per square foot. This weight gives finished dining tables and desks a solid, grounded feel without becoming unmanageably heavy during assembly.
On the French Monnin hardness scale, Ayan rates at 5.6 at 12% moisture content. On the Monnin scale, higher numbers indicate greater resistance to indentation (it is an independent metric and is never converted to a Janka rating). Mechanically, Ayan delivers serious structural strength: static bending strength (modulus of rupture) is 116 MPa (about 16,820 psi), crushing strength is 64 MPa (about 9,280 psi), and the modulus of elasticity reaches 14,740 MPa (about 2,138,000 psi). This high stiffness resists sagging across open table spans.
Shrinkage and Movement Next to an Epoxy River
When embedding wood slabs alongside a rigid, cured epoxy resin channel, dimensional stability is paramount. Ayan demonstrates moderate, predictable movement characteristics. Total tangential shrinkage measures 5.8%, while total radial shrinkage is 3.6%. The resulting ratio of tangential to radial shrinkage (St/Sr) is 1.6.
Because an St/Sr ratio closer to 1.0 indicates a lower tendency to cup or twist during seasonal shifts, a 1.6 ratio puts Ayan in a very manageable range. The coefficient of volumetric shrinkage is 0.54% per 1% change in moisture content, with a fiber saturation point of 23%. While it does move with ambient relative humidity, keeping the timber properly acclimated to indoor conditions ensures the wood-epoxy bond line remains sound.
Drying Behavior and Kiln Schedules
According to CIRAD testing, Ayan has a normal drying rate. It poses only a slight risk of distortion and a slight risk of checking during the drying process. Furthermore, it carries no known specific risk of casehardening or cell collapse.
For shops operating drying kilns or verifying commercial kiln runs, the recommended drying schedule spans temperatures between 48 °C and 60 °C (approximately 118 °F to 140 °F). Ensuring uniform drying down to interior moisture levels before pouring epoxy prevents stress along the casting perimeter.
Machining, Fastening, and Finish Prep
Working with Ayan requires proper tooling. The CIRAD data notes that Ayan exerts a high blunting effect on cutters. To maintain clean edges and prevent burn marks:
- Use stellite-tipped saw teeth for rip and crosscut operations.
- Employ tungsten carbide knives and router bits for surfacing and leveling slabs.
- Expect some machining difficulties caused by irregular or interlocked grain.
- Apply pore filling prior to final finishing coats to achieve a smooth, high-quality surface.
For joinery and mechanical fasteners, nailing and screwing properties are good, but pre-boring is necessary. CIRAD explicitly highlights that pre-boring is recommended especially for large nails to prevent splitting. When it comes to finishing and moisture exposure, be aware that Ayan contains water-soluble yellow extracts that can stain elements in contact with the wood under wet conditions.
Durability, Environmental Status, and Uses
CIRAD classifies Ayan heartwood as durability class 3 (moderately durable against wood-decay fungi), Class D against dry-wood borers (durable, with risk limited to sapwood), and Class M (moderately durable against termites). Its heartwood treatability is Class 4 (not permeable). Its natural durability corresponds to Use Class 2 (interior or under cover, where dampness is possible). In temperate regions, its exterior use without preservative treatment is limited because it is prone to attack by Coriolus versicolor fungi.
Environmentally, Ayan is not listed in the CITES Appendices (Washington Convention 2025). CIRAD documents its common end-uses in cabinetwork (high class furniture), current furniture components, flooring, interior and exterior joinery, panelling, and sliced veneer.
| Property | CIRAD Tropix value | What it means / US units |
|---|---|---|
| Botanical name(s) | Distemonanthus benthamianus | |
| Other trade names | Distemonanthus | |
| Colour / texture / grain | Yellow; texture medium; grain interlocked; interlocked grain slight | |
| Specific gravity (12% MC) | 0.73 | about 45.6 lb/ft³; a 2-inch-thick slab weighs about 7.6 lb per sq ft |
| Monnin hardness (12% MC) | 5.6 | French hardness scale; higher = harder (not a Janka value) |
| Total tangential shrinkage | 5.8 % | green to oven-dry |
| Total radial shrinkage | 3.6 % | green to oven-dry |
| Ratio St/Sr | 1.6 | closer to 1 = less cupping tendency |
| Coefficient of volumetric shrinkage | 0.54 % per % MC | volume change per 1% change in moisture content |
| Fibre saturation point | 23 % | |
| Thermal conductivity | 0.24 W/(m·K) | |
| Crushing strength (12% MC) | 64 MPa | about 9,280 psi |
| Static bending strength (12% MC) | 116 MPa | about 16,820 psi |
| Modulus of elasticity (12% MC) | 14,740 MPa | about 2,138,000 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 4 – 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 | 48–60 °C | about 118–140 °F |
| Machining | blunting 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).
Is It a Good Epoxy Table Wood?
Ayan is an exceptional candidate for indoor epoxy river tables and high-end furniture. Its luminous yellow-to-brown heartwood, distinct sapwood margins, and occasional striking figure create beautiful contrast against tinted or clear resin pours. With a low St/Sr ratio of 1.6, solid Monnin hardness of 5.6, and minimal drying defects, it stays stable along the resin bond. Builders must simply account for its high tool wear by using carbide cutters, pre-drill all hardware connections, and seal surfaces thoroughly to keep its water-soluble yellow extractives from leaching under moisture.
Sources
Published October 30, 2026. Sources are linked in the text.
Header image: original graphic by BigEpoxy.com.
Staff note: When inspecting Ayan logs or thick rough-sawn slabs for an epoxy project, watch closely for internal stresses and wind shakes highlighted in the CIRAD notes, as these can cause unexpected checks or splits to open along the river channel during resawing or surfacing. (Source: CIRAD Tropix 7 technical sheet: Ayan.)