Punah (*Tetramerista glabra*) in Custom Epoxy Tabletops
Punah (Tetramerista glabra) is a Southeast Asian hardwood harvested primarily across Indonesia and Malaysia. For woodworkers evaluating imported species for custom epoxy river tables and resin projects, understanding this wood requires a close look at its physical, mechanical, and seasoning characteristics. The technical sheet published by CIRAD provides the laboratory data needed to assess how Punah performs under shop tools and alongside cured epoxy pours.
Appearance, Grain, and Slab Width Potential
CIRAD describes the wood as light brown, frequently displaying light yellow to light brown tones accompanied by subtle pink glints. The pores often feature noticeable red and white deposits. When green, the timber gives off an unpleasant odour, which subsides as the wood cures and dries. The sapwood measures from 4 to 7 cm thick and is not clearly demarcated from the heartwood.
In terms of structure, Punah has a medium texture. The grain runs straight or interlocked, with the interlocked grain rated as slight, though oblique grain is observed at times. CIRAD notes log diameters ranging from 60 to 100 cm. For table makers, this diameter range provides potential for medium to broad single-slab live-edge boards or split bookmatched pairs suited for river table construction.
Density, Hardness, and Mechanical Strength
Punah is a solid, moderately heavy timber with a specific gravity of 0.73 at 12% moisture content. That places its density at about 45.6 lb/ft³, meaning a standard 2-inch-thick tabletop slab weighs approximately 7.6 lb per sq ft. This provides substantial heft for residential or commercial furniture bases.
Hardness is measured by CIRAD on the French Monnin scale, scoring 3.1 at 12% moisture content. The Monnin scale uses a cylinder indentation test where higher numerical values correspond to harder timber; it should not be confused with or converted to Janka values. Mechanically, Punah exhibits sound structural integrity, with a crushing strength of 66 MPa (about 9,570 psi), a static bending strength of 105 MPa (about 15,230 psi), and a modulus of elasticity of 16,300 MPa (about 2,364,000 psi).
| Property | CIRAD Tropix value | What it means / US units |
|---|---|---|
| Botanical name(s) | Tetramerista glabra | |
| Colour / texture / grain | Light brown; texture medium; grain straight or 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) | 3.1 | French hardness scale; higher = harder (not a Janka value) |
| Total tangential shrinkage | 9.2 % | green to oven-dry |
| Total radial shrinkage | 5.8 % | green to oven-dry |
| Ratio St/Sr | 1.6 | closer to 1 = less cupping tendency |
| Coefficient of volumetric shrinkage | 0.61 % per % MC | volume change per 1% change in moisture content |
| Fibre saturation point | 30 % | |
| Thermal conductivity | 0.24 W/(m·K) | |
| Crushing strength (12% MC) | 66 MPa | about 9,570 psi |
| Static bending strength (12% MC) | 105 MPa | about 15,230 psi |
| Modulus of elasticity (12% MC) | 16,300 MPa | about 2,364,000 psi |
| Decay (fungi) resistance | Durability class 3 – moderately 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 rapid to normal; distortion: high risk; checking: high risk; collapse: no known specific risk; casehardening: no known specific risk | |
| Suggested kiln program temperatures | 53–65 °C | about 127–149 °F |
| Machining | blunting normal; saw teeth: ordinary or alloy steel; cutting tools: ordinary | |
| 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 River Interface
Whenever wood is permanently bonded to a rigid cured resin river, dimensional stability is paramount. Punah exhibits a total tangential shrinkage of 9.2% and a total radial shrinkage of 5.8%, resulting in an St/Sr ratio of 1.6. Its coefficient of volumetric shrinkage is 0.61% per % moisture content, and its fibre saturation point is 30%.
A volumetric shrinkage coefficient of 0.61% indicates moderate to high volume change as moisture levels shift. Because the wood moves significantly across relative humidity swings, building an epoxy river table requires that the timber be thoroughly conditioned to equilibrium moisture content before pouring. Significant post-cure dimensional movement could exert high shear stress directly against the epoxy joint.
Drying Characteristics and Risk Factors
Drying Punah demands strict attention. According to CIRAD, the drying rate ranges from rapid to normal, but it carries a high risk of distortion and a high risk of checking. There is no known specific risk of collapse or casehardening. To minimize defects during seasoning, CIRAD notes that drying requires care, including top weighting of the lumber piles and applying end-coating to prevent end-checking and cracking. Recommended kiln temperatures in suggested schedules range from 53 to 65 °C (about 127 to 149 °F).
Machining, Fastening, and Finishing
In the workshop, Punah has a normal blunting effect on cutting edges, and standard ordinary or alloy steel tools perform satisfactorily. However, sawteeth may experience slight gumming from natural resin. CIRAD points out that during planing, the surface tends to be fibrous and requires a careful sanding routine to achieve a clean plane.
For joinery and mechanical fasteners, nailing and screwing properties are good, though pre-boring is necessary to prevent splitting, particularly in thin material. When preparing the wood for topcoats, CIRAD notes that filling is required to obtain a good finish. For resin work, applying a thin seal coat of epoxy across all exposed faces and live edges—following the resin manufacturer’s technical data sheet—helps lock in deposits, seal medium pores, and prepare the fibrous surface for casting.
Durability and CITES Status
Punah heartwood is classified as Durability class 3 (moderately durable) against xylophagous fungi. However, it is susceptible (Class S) to termites and dry-wood borers across all the wood. Heartwood treatability is poorly permeable (Class 3), and its natural durability places it in Use class 1 (interior uses without dampness). The species is not listed in the CITES Appendices (Washington Convention 2025).
Common commercial end-uses listed for the wood include current furniture or furniture components, flooring, interior joinery, interior panelling, boxes and crates, exterior joinery, and vehicle or container flooring.
Is It a Good Epoxy Table Wood?
Punah is a viable, attractive choice for indoor epoxy river tables, but it requires deliberate shop preparation. Its warm light brown tones, pink glints, and medium pore structure create an appealing organic backdrop next to tinted or transparent resin. However, because CIRAD highlights a high risk of checking, high risk of distortion, and a fibrous surface on planing, builders must verify that slabs are thoroughly dry, weight-stabilized during seasoning, pre-bored for fasteners, sealed to address porosity, and kept strictly in climate-controlled indoor environments.
Sources
Published October 31, 2026. Sources are linked in the text.
Header image: original graphic by BigEpoxy.com.
Staff note: CIRAD specifically notes that sawteeth can experience slight gumming from resin when cutting Punah, so keep blade cleaner handy at the table saw or bandsaw to prevent heat buildup and burn marks. (Source: CIRAD Tropix 7 technical sheet: Punah.)