Introduction to Yemane for Epoxy River Tables
Yemane (Gmelina arborea), also known commercially as Gmelina, originates from Asia-Oceania with primary production in countries such as India, Laos, Myanmar, and Thailand. It is also planted extensively across Africa for reforestation. For woodworkers and custom epoxy builders, Yemane offers an accessible medium-density hardwood suitable for interior tabletops, panelling, and fine furniture. According to international trade data, the species is not listed in the CITES Appendices (Washington Convention 2025).
When assessing Yemane boards or live-edge slabs, the wood displays a light yellow to light brown coloration, frequently highlighted by reddish or brownish veins. The sapwood measures from 5 to 7 cm in thickness and is not clearly demarcated from the heartwood. Logs commonly arrive in diameters ranging from 40 to 80 cm. In the workshop, builders will notice a medium texture, slight interlocked grain, an oily feel to the touch, and the presence of knots of variable sizes across the timber face.
Density, Weight, and Hardness
In the technical sheet published by CIRAD Tropix, mature Yemane exhibits an average specific gravity of 0.49 at 12% moisture content. In everyday shop terms, this yields an air-dry density of about 30.6 lb/ft³. A 2-inch-thick tabletop slab weighs approximately 5.1 lb per sq ft. This moderate weight makes Yemane slabs relatively easy to maneuver through planer passes, routing jigs, and mold setups compared to denser tropical hardwoods.
Mechanical resistance reflects this moderate density. The Monnin hardness of Yemane is 1.9. The Monnin hardness test is a standardized French scale based on cylinder indentation where a higher number denotes a harder timber; it is not comparable to the Janka hardness test and should never be converted into Janka figures. Additional mechanical values include a crushing strength of 32 MPa (about 4,640 psi), a static bending strength of 64 MPa (about 9,280 psi), and a modulus of elasticity of 9,120 MPa (about 1,323,000 psi). While soft enough to dent if subjected to sharp impacts, it provides ample structural integrity for dining tables and desks.
Shrinkage, Movement, and Epoxy River Bonding
Wood movement is one of the most critical factors in deep-pour epoxy river design. When wood moves across seasonal humidity shifts, it exerts shearing stress along the resin-to-wood interface. CIRAD Tropix reports that Yemane exhibits low total shrinkage values from green to oven-dry:
- Total tangential shrinkage: 5.9 %
- Total radial shrinkage: 2.8 %
- Tangential to radial ratio (St/Sr): 2.1
- Coefficient of volumetric shrinkage: 0.45 % per % change in moisture content
- Fibre saturation point: 26 %
The tangential shrinkage of 5.9 % is quite modest, and the volumetric coefficient of 0.45 % per percent moisture content demonstrates good dimensional stability once conditioned to indoor ambient conditions. However, the T/R ratio of 2.1 indicates some tendency toward cupping if moisture gradients develop across wide plainsawn boards. Ensuring thorough resin encapsulation and sealing both the top and underside of the table prevents uneven atmospheric absorption.
Drying Risks and Kiln Conditioning
Yemane dries at a slow pace. Fortunately, it presents no risk or very slight risk of distortion and no risk or very slight risk of checking during the drying process. In addition, there is no known specific risk of cellular collapse. The primary drying defect to watch for is casehardening, which is documented as a known risk for the species. Suggested kiln schedules operate with temperatures between 55 °C and 65 °C (about 131 °F to 149 °F). Slabs must be fully conditioned and equalized to eliminate internal drying stress before cutting the center river channel.
Machining, Fasteners, and Durability
Tool blunting when working Yemane is classified as normal. Standard cutting tools and saw blades with ordinary or alloy steel teeth cut the wood cleanly without requiring specialized tungsten carbide tooling. When building table bases or attaching structural aprons, take note that Yemane offers poor nailing and screwing resistance. Always pre-drill holes and rely on threaded inserts or mechanical fasteners designed for lighter hardwoods rather than driving standard wood screws directly into the underside.
Regarding biological resistance, CIRAD Tropix rates Yemane heartwood as Durability class 4 (poorly durable), noting that the wood is poorly to moderately resistant to fungi. It is classified as Class S (susceptible) to termites and dry-wood borers throughout all of the wood, and its heartwood treatability is Class 3 (poorly permeable). As a result, its natural durability places it strictly in Class 1 (inside, no dampness). Yemane is suited for climate-controlled indoor living spaces and should not be used in outdoor epoxy installations. CIRAD lists its practical end-uses in current furniture and furniture components, interior joinery, interior panelling, sculpture, musical instruments, sliced veneer, boxes, crates, and pencils.
| Property | CIRAD Tropix value | What it means / US units |
|---|---|---|
| Botanical name(s) | Gmelina arborea | |
| Other trade names | Gmelina | |
| Colour / texture / grain | Light yellow; texture medium; grain interlocked; interlocked grain slight | |
| Specific gravity (12% MC) | 0.49 | about 30.6 lb/ft³; a 2-inch-thick slab weighs about 5.1 lb per sq ft |
| Monnin hardness (12% MC) | 1.9 | French hardness scale; higher = harder (not a Janka value) |
| Total tangential shrinkage | 5.9 % | green to oven-dry |
| Total radial shrinkage | 2.8 % | green to oven-dry |
| Ratio St/Sr | 2.1 | 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 | 26 % | |
| Thermal conductivity | 0.17 W/(m·K) | |
| Crushing strength (12% MC) | 32 MPa | about 4,640 psi |
| Static bending strength (12% MC) | 64 MPa | about 9,280 psi |
| Modulus of elasticity (12% MC) | 9,120 MPa | about 1,323,000 psi |
| Decay (fungi) resistance | Durability class 4 – poorly durable | |
| Termite resistance | Class S – susceptible | |
| Dry-wood borer resistance | Class S – susceptible (risk in all the wood) | |
| Heartwood treatability | Class 3 – poorly permeable | |
| Use class from natural durability | Class 1 – inside (no dampness) | |
| Drying | rate slow; distortion: no risk or very slight risk; checking: no risk or very slight risk; collapse: no known specific risk; casehardening: yes | |
| Suggested kiln program temperatures | 55–65 °C | about 131–149 °F |
| Machining | blunting normal; saw teeth: ordinary or alloy steel; cutting tools: ordinary | |
| Nailing and screwing | Poor | |
| CITES status | This species is not listed in the CITES Appendices (Washington Convention 2025). Notes. Also called GMELINA, used for reforestation outside its native area. This species is used very widely in plantations in Africa. |
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).
Practical Pre-Pour Checklist for Yemane Slabs
- Verify indoor moisture equilibrium: Test your Yemane slab with an accurate moisture meter to verify that the core and surface have stabilized to local interior standards before building your river mold.
- Relieve casehardening stresses: Inspect sawn boards for casehardening before profiling the river edges; execute stress-relief cuts or flattening passes if internal tension is observed.
- Surface clean natural oils: Clean the contact edges facing the epoxy channel with a shop solvent to remove surface oils mentioned in the species profile, allowing deep mechanical adhesion.
- Inspect and secure knots: Review the slab for variable knots; brush penetrating epoxy into open fissures and knots prior to the primary river pour to prevent hidden air entrapment.
- Seal all exposed wood faces: Apply a dedicated epoxy seal coat over the live edges and flat surfaces to reduce bubble outgassing from the medium-textured pores.
- Plan base attachments with inserts: Because screw-holding capacity is rated as poor, map out threaded metal inserts rather than coarse wood screws to attach legs and support brackets.
Sources
Published October 30, 2026. Sources are linked in the text.
Header image: original graphic by BigEpoxy.com.
Staff note: Because CIRAD Tropix highlights the presence of knots of variable sizes throughout Yemane lumber, check both sides of your slab for knot clusters before sealing, as knots can harbor deep voids that pull resin out of your mold or release micro-bubbles during the main river pour. (Source: CIRAD Tropix 7 technical sheet: Yemane.)