Working with Louro Vermelho in Epoxy Tabletops
Louro vermelho (Sextonia rubra, synonymous with Ocotea rubra), also known commercially as Determa, is a Latin American hardwood harvested primarily from Brazil, French Guiana, Guyana, and Suriname. For custom furniture makers and resin woodworkers evaluating tropical hardwoods, technical data published by the French research institute CIRAD Tropix provides critical insight into how this species behaves during drying, machining, and casting.
Before pouring hundreds of dollars of resin alongside large timber slabs, understanding the mechanical and physical realities of the species is vital. Louro vermelho presents attractive grain and impressive biological durability, but its drying profile requires strict shop discipline.
Appearance, Figure, and Slab Anatomy
Louro vermelho lumber and slabs display a light brown heartwood often enriched by subtle pink to red-brown shades. The wood texture is medium, and while the grain can be straight, it frequently displays slight interlocked grain, which adds visual character to wide tabletop surfaces. Log diameters typically range from 50 to 90 cm, yielding generous board widths. The sapwood is clearly demarcated from the heartwood with a thickness ranging between 3 and 5 cm.
When inspecting rough-sawn slabs or timber cuts, builders should watch closely for natural internal stress separations. The CIRAD Tropix technical sheet explicitly notes the possible presence of wind shakes in the wood. Any internal ring shakes or heart splits must be completely mapped and sealed prior to pouring an epoxy river to prevent resin migration or trapped air release.
Weight, Strength, and Hardness
Louro vermelho is a moderately dense timber. At 12% moisture content, its specific gravity averages 0.66, which equates to a bulk density of about 41.2 lb/ft³. For river table builders calculating supporting base capacities, a 2-inch-thick slab weighs approximately 6.9 lb per sq ft.
The wood exhibits a Monnin hardness of 2.5. The Monnin test is a standardized French scale based on indentation cylinder depth, where higher values indicate harder woods. It is fundamentally distinct from American Janka indentation ratings and cannot be directly mathematically translated to Janka. At a Monnin score of 2.5, CIRAD classifies its hardness as relatively soft, noting that the species is not recommended for environments facing strong mechanical constraints. While perfectly rigid enough for decorative tabletops and high-class cabinetwork, surfaces subject to aggressive wear may dent more easily than harder tropical alternatives.
Mechanically, Louro vermelho exhibits a crushing strength of 51 MPa (about 7,400 psi), a static bending strength of 81 MPa (about 11,750 psi), and a modulus of elasticity of 14,170 MPa (about 2,055,000 psi).
Shrinkage, Movement, and the Epoxy Bond
Whenever cured epoxy resin is poured directly against raw timber edges, differential movement becomes the primary long-term threat to the bond. Louro vermelho exhibits a total tangential shrinkage of 8.8% and a total radial shrinkage of 4.5%, leading to a tangential-to-radial (St/Sr) ratio of 2.0. Its coefficient of volumetric shrinkage is 0.54% per 1% change in moisture content, with a fibre saturation point measured at 29%.
A ratio of 2.0 indicates moderate tendency toward cupping across flatsawn sections compared to quartersawn faces. Because epoxy resin has virtually no moisture movement once cured, swings in relative humidity will cause the wood to shrink and swell against the stationary resin cast. Sealing all tabletop faces thoroughly and ensuring the slab is acclimated to interior equilibrium moisture content before casting will mitigate edge shear stress along the river joint.
Drying Pitfalls: The Slab Thickness Limit
Drying is by far the most critical phase when considering Louro vermelho for thick table builds. The drying rate is slow, but the risks are severe: CIRAD identifies a high risk of checking, along with active risks for collapse and casehardening. Distortions carry a slight risk.
Crucially, the technical data specifically notes that artificial drying is not recommended for timber thicknesses greater than 40 mm. Furthermore, drying problems are identified as an issue that may restrict the wood’s end-uses. Kiln schedules typically stay moderate (recommended program temperatures range from 45 to 65 °C, or about 113 to 149 °F), and high-temperature steaming at 80 °C is recorded to improve drying. For table builders seeking 2-inch or 3-inch live-edge slabs, sourcing timber that has dried slowly without internal checking or collapse requires exceptional supplier scrutiny.
Machining, Fastening, and Natural Durability
Louro vermelho behaves pleasantly under sharp tools. The blunting effect on cutter heads is normal, allowing the use of ordinary cutting tools and ordinary or alloy steel saw teeth. It also grades well for slicing and peeling when converted into veneers.
Mechanical fastening, however, demands attention. CIRAD Tropix rates both nailing and screwing as poor, observing that nail holding is variable. Table bases and aprons should use threaded inserts, machine bolts, and slotted brackets rather than relying on direct coarse woodscrews driven into end grain or face grain.
In terms of durability, the heartwood demonstrates excellent natural resilience. It is rated Durability Class 2 (durable) against xylophagous fungi, Class D (durable) against dry-wood borers (with risks limited to the sapwood), and Class D (durable) against termites. The heartwood is Class 4 (not permeable) to chemical treatments. Beyond furniture, recorded uses include cabinetwork, interior and exterior joinery, boat planking, and mouldings. The timber is not listed in the CITES Appendices (Washington Convention 2025).
| Property | CIRAD Tropix value | What it means / US units |
|---|---|---|
| Botanical name(s) | Sextonia rubra, Ocotea rubra (synonymous) | |
| Other trade names | Determa | |
| Colour / texture / grain | Light brown; texture medium; grain interlocked; interlocked grain slight | |
| Specific gravity (12% MC) | 0.66 | about 41.2 lb/ft³; a 2-inch-thick slab weighs about 6.9 lb per sq ft |
| Monnin hardness (12% MC) | 2.5 | French hardness scale; higher = harder (not a Janka value) |
| Total tangential shrinkage | 8.8 % | green to oven-dry |
| Total radial shrinkage | 4.5 % | green to oven-dry |
| Ratio St/Sr | 2.0 | 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 | 29 % | |
| Thermal conductivity | 0.22 W/(m·K) | |
| Crushing strength (12% MC) | 51 MPa | about 7,400 psi |
| Static bending strength (12% MC) | 81 MPa | about 11,750 psi |
| Modulus of elasticity (12% MC) | 14,170 MPa | about 2,055,000 psi |
| Decay (fungi) resistance | Durability class 2 – durable | |
| Termite resistance | Class D – durable | |
| Dry-wood borer resistance | Class D – durable (sapwood demarcated, risk limited | |
| Heartwood treatability | Class 4 – not permeable | |
| Use class from natural durability | Class 3 – not in ground contact, outside | |
| Drying | rate slow; distortion: slight risk; checking: high risk; collapse: yes; casehardening: yes | |
| Suggested kiln program temperatures | 45–65 °C | about 113–149 °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). |
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?
Louro vermelho makes an attractive, workable tabletop material, but it presents specific trade-offs for epoxy builders. Its warm pinkish-brown hues, modest blunting, and strong rot resistance make it suitable for fine furniture and interior paneling. However, its high checking risk, susceptibility to collapse, and CIRAD recommendation against drying material over 40 mm thick mean that obtaining pristine, defect-free thick river slabs is challenging. If using Louro vermelho, ensure the material is meticulously dried below 40 mm or built from stable, well-acclimated boards, reinforce all screw attachments, and inspect thoroughly for internal wind shakes before pouring resin.
Sources
Published October 30, 2026. Sources are linked in the text.
Header image: original graphic by BigEpoxy.com.
Staff note: If you are attaching a steel base or heavy apron, remember that CIRAD Tropix rates nailing and screwing holding in Louro vermelho as poor and variable; using threaded inserts with machine bolts in slotted holes is far safer than driving conventional screws directly into the underside of the slab. (Source: CIRAD Tropix 7 technical sheet: Louro vermelho.)