Overview: Guanacaste in Epoxy Tablemaking
Guanacaste encompasses timber from the genus Enterolobium, specifically Enterolobium contortisiliquum, Enterolobium cyclocarpum, and Enterolobium maximum. Native to Latin America—including producing countries such as Argentina, Brazil, Colombia, Paraguay, and Venezuela—this species produces large logs typically ranging from 60 to 100 cm in diameter. With its broad growth profiles and contrasting edges, it is frequently sourced as wide live-edge slabs for furniture builders and resin artisans.
According to technical data published in the CIRAD Tropix technical sheet, Guanacaste offers an appealing combination of moderate weight, low shrinkage, and rapid drying. Understanding its physical properties is crucial when pairing these slabs with epoxy resin, where stability, adhesion, and surface preparation dictate long-term project success.
Appearance, Texture, and Slab Characteristics
The heartwood of Guanacaste ranges from light brown to brown, offset by clearly demarcated sapwood that measures between 3 to 6 cm in thickness. For live-edge river tables, this light sapwood band creates a natural visual border against darker epoxy pours. The wood exhibits a coarse texture and grain that runs straight to slightly interlocked. CIRAD Tropix notes that Enterolobium cyclocarpum may contain tension wood, which can occasionally result in a fuzzy surface during cutting or planning.
Density, Hardness, and Structural Strength
Guanacaste is a medium-density hardwood. At 12% moisture content, it has an average specific gravity of 0.49, which corresponds to a density of about 30.6 lb/ft³. A 2-inch-thick slab weighs approximately 5.1 lb per sq ft, making large dining tables and conference tables manageable to lift, move, and mount to metal or wooden bases.
On the mechanical side, Guanacaste records a Monnin hardness of 2.1 at 12% moisture content. The Monnin scale is a French testing standard where higher values represent harder woods; it is not a Janka rating and should not be directly equated to one. A Monnin score of 2.1 places Guanacaste among softer-to-medium commercial hardwoods, meaning it dents more easily than dense tropical species. In structural measurements, it exhibits a crushing strength of 40 MPa (about 5,800 psi), a static bending strength of 63 MPa (about 9,140 psi), and a modulus of elasticity of 9,650 MPa (about 1,400,000 psi).
| Property | CIRAD Tropix value | What it means / US units |
|---|---|---|
| Botanical name(s) | Enterolobium contortisiliquum, Enterolobium cyclocarpum, Enterolobium maximum | |
| Colour / texture / grain | Brown; texture coarse; grain straight or 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) | 2.1 | French hardness scale; higher = harder (not a Janka value) |
| Total tangential shrinkage | 4.5 % | green to oven-dry |
| Total radial shrinkage | 2.3 % | green to oven-dry |
| Ratio St/Sr | 2.0 | closer to 1 = less cupping tendency |
| Coefficient of volumetric shrinkage | 0.35 % per % MC | volume change per 1% change in moisture content |
| Fibre saturation point | 24 % | |
| Thermal conductivity | 0.17 W/(m·K) | |
| Crushing strength (12% MC) | 40 MPa | about 5,800 psi |
| Static bending strength (12% MC) | 63 MPa | about 9,140 psi |
| Modulus of elasticity (12% MC) | 9,650 MPa | about 1,400,000 psi |
| Decay (fungi) resistance | Durability class 5 – not durable | |
| Termite resistance | Class S – susceptible | |
| Dry-wood borer resistance | Class D – durable (sapwood demarcated, risk limited | |
| Heartwood treatability | Class 1 – easily permeable | |
| Use class from natural durability | Class 1 – inside (no dampness) | |
| Drying | rate rapid; distortion: no risk or very slight risk; checking: no risk or very slight risk; collapse: no known specific risk; casehardening: no known specific risk | |
| 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 | 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).
Shrinkage, Wood Movement, and Epoxy Interface Stability
When pouring an epoxy river table, matching the cured epoxy to a stable wood is essential. As relative humidity fluctuates, wood expands and contracts across its grain; excessive movement can generate shear stress at the wood-epoxy bond line.
Guanacaste displays favorable dimensional stability. Its total tangential shrinkage is 4.5%, and total radial shrinkage is 2.3%, yielding a tangential-to-radial shrinkage ratio (St/Sr) of 2.0. Its coefficient of volumetric shrinkage is 0.35% per percent change in moisture content, with a fiber saturation point at 24%. Because its total shrinkage numbers are relatively low, Guanacaste exerts minimal movement forces along casting boundaries compared to heavier, high-movement timbers, helping maintain bond integrity inside dry interior environments.
Drying Behavior and Kiln Schedules
According to the CIRAD Tropix findings, Guanacaste dries at a rapid rate. It displays exceptional tolerance during the drying cycle, showing no risk or very slight risk of distortion, and no risk or very slight risk of checking. Furthermore, there is no known specific risk of collapse or casehardening. CIRAD outlines kiln temperatures ranging between 55 °C and 65 °C (about 131 °F to 149 °F) throughout its drying program, ensuring slabs reach target moisture levels without degrading.
Machining, Assembly, and Shop Safety
Guanacaste is straightforward to work with standard woodworking equipment. CIRAD Tropix rates tool blunting as normal, allowing builders to utilize ordinary cutting tools and ordinary or alloy steel sawteeth. Nailing and screwing properties are rated as good. Heartwood treatability is classified as Class 1 (easily permeable), which indicates the cellular structure accepts penetrating sealers and epoxy base coats readily.
Shop safety and surface finishing require attention with this species. The sawdust of Enterolobium cyclocarpum is officially noted as irritant, requiring reliable dust extraction and personal protective gear when sanding or shaping. Additionally, due to potential tension wood, woodworkers should monitor for fuzzy surfaces and adjust tooling sharpness to achieve clean cuts prior to casting.
Durability and Regulatory Status
Guanacaste heartwood is classified as Durability Class 5 (not durable) regarding xylophagous fungi and Class S (susceptible) regarding termites, though dry-wood borers fall under Class D (durable, with risk limited to the sapwood). Its natural durability corresponds to Use Class 1, designating the timber strictly for interior uses with no dampness. This species is not listed in the CITES Appendices (Washington Convention 2025). Its industrial uses include current furniture and furniture components, carpentry, interior joinery, interior panelling, blockboard, and sliced veneer.
Is Guanacaste a Good Epoxy Table Wood?
Guanacaste is well suited for interior epoxy river tables and decorative desks. Its moderate weight (about 30.6 lb/ft³), rapid drying, low checking risk, and low total tangential shrinkage (4.5%) make it a predictable partner for deep-pour epoxy resins. However, because of its modest Monnin hardness (2.1) and non-durable rating against rot and termites, it should be kept indoors in dry conditions (Use Class 1) and protected with a durable film or penetrating finish to resist everyday surface wear.
Sources
Published October 30, 2026. Sources are linked in the text.
Header image: original graphic by BigEpoxy.com.
Staff note: Because CIRAD classifies Guanacaste heartwood as Class 1 (easily permeable) and coarse in texture, applying a thin, thorough epoxy seal coat to the live edge before the main pour is especially important to prevent air from escaping into the casting cavity. (Source: CIRAD Tropix 7 technical sheet: Guanacaste.)