Working with Massaranduba in Epoxy River Tables
Massaranduba, encompassing botanical species such as Manilkara bidentata, Manilkara huberi, and Manilkara p.p. from Latin America, is also known in the timber trade as Beefwood or Bulletwood. Recognized in the CIRAD Tropix technical sheet for its remarkable density and strength, this species provides an ultra-dense, deep-toned option for custom furniture, heavy tabletops, and wood-epoxy hybrid builds.
Understanding how this heavy hardwood behaves under tooling, across moisture shifts, and alongside a rigid epoxy resin river is vital for planning a successful tabletop build.
Appearance, Color, and Figure
Massaranduba displays a rich red-brown heartwood, frequently exhibiting dark red-brown tones with purplish shades. The sapwood is clearly demarcated from the heartwood, measuring from 4 to 6 cm in thickness on logs that range from 60 to 120 cm in diameter. The grain is typically straight, with interlocked grain noted as absent, and the wood features a fine, uniform texture that finishes smoothly when properly prepped.
Weight, Hardness, and Mechanical Strength
This is exceptionally heavy timber. At 12% moisture content, Massaranduba carries an average specific gravity of 1.10, translating to a density of about 68.7 lb/ft³. A 2-inch-thick tabletop slab weighs approximately 11.4 lb per square foot, and the green logs do not float.
Its hardness is measured on the Monnin scale, a French testing method where higher numbers signify increasing hardness (this scale does not correlate to Janka values and must not be converted). Massaranduba rates at 12.9 on the Monnin scale, reflecting an extremely dense, scratch-resistant surface. Mechanically, it delivers high performance across all structural metrics, with a crushing strength of 89 MPa (about 12,910 psi), a static bending strength of 170 MPa (about 24,660 psi), and a modulus of elasticity of 24,410 MPa (about 3,540,000 psi).
Shrinkage, Movement, and River Table Stability
The CIRAD Tropix data classifies Massaranduba as a moderately stable wood. Its total shrinkage values from green to oven-dry are 9.4% tangential and 7.1% radial, with a fiber saturation point of 27%. The coefficient of volumetric shrinkage is 0.75% per 1% change in moisture content.
Crucially for river table builders, the ratio of tangential to radial shrinkage (St/Sr) is 1.3. A ratio this close to 1.0 indicates a low cupping tendency across board faces. However, because its cumulative shrinkage values and volumetric coefficient are relatively high, wide slabs exposed to ambient humidity shifts can exert massive shear stresses against an epoxy interface. Thorough acclimation before casting is essential to protect the epoxy-to-wood joint from pulling apart.
Durability, Permeability, and CITES Status
Massaranduba heartwood is exceptionally resilient. CIRAD Tropix rates it as Durability Class 1 (very durable) against wood-decay fungi, Class D (durable) against dry-wood borers, and Class D (durable) against termites. Heartwood treatability is Class 4 (not permeable). It naturally covers Class 4 end-use (ground or freshwater contact) and even marine use (salt or brackish water) due to its high density and hardness. According to the Washington Convention (2025), Massaranduba is not listed in the CITES Appendices. CIRAD Tropix documents its traditional end-uses in furniture components, indoor staircases, ship planking, industrial flooring, decking, and heavy carpentry.
| Property | CIRAD Tropix value | What it means / US units |
|---|---|---|
| Botanical name(s) | Manilkara bidentata, Manilkara huberi, Manilkara p.p. | |
| Other trade names | Beefwood, Bulletwood | |
| Colour / texture / grain | Red brown; texture fine; grain straight; interlocked grain absent | |
| Specific gravity (12% MC) | 1.10 | about 68.7 lb/ft³; a 2-inch-thick slab weighs about 11.4 lb per sq ft |
| Monnin hardness (12% MC) | 12.9 | French hardness scale; higher = harder (not a Janka value) |
| Total tangential shrinkage | 9.4 % | green to oven-dry |
| Total radial shrinkage | 7.1 % | green to oven-dry |
| Ratio St/Sr | 1.3 | closer to 1 = less cupping tendency |
| Coefficient of volumetric shrinkage | 0.75 % per % MC | volume change per 1% change in moisture content |
| Fibre saturation point | 27 % | |
| Thermal conductivity | 0.35 W/(m·K) | |
| Crushing strength (12% MC) | 89 MPa | about 12,910 psi |
| Static bending strength (12% MC) | 170 MPa | about 24,660 psi |
| Modulus of elasticity (12% MC) | 24,410 MPa | about 3,540,000 psi |
| Decay (fungi) resistance | Durability class 1 – very 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 4 – in ground or fresh water contact | |
| Drying | rate slow; distortion: medium risk; checking: medium risk; collapse: no known specific risk; casehardening: yes | |
| Suggested kiln program temperatures | 44–60 °C | about 111–140 °F |
| Machining | blunting fairly 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).
Pros and Cons for Wood and Epoxy Builds
- Pros: High wear resistance with a Monnin hardness of 12.9; low cupping risk indicated by a 1.3 tangential-to-radial shrinkage ratio; Class 1 fungal decay resistance; striking dark red-brown and purplish heartwood coloration.
- Cons: Extreme weight (about 68.7 lb/ft³ at 12% MC) demands heavy-duty bases; slow drying rate with medium checking and distortion risks; fairly high tool blunting requires carbide tooling; Class 4 non-permeable heartwood demands careful gluing practices.
Build Notes for Woodworkers
- Slab Selection: Source mature wood from logs 60 to 120 cm wide. Account for the 4 to 6 cm sapwood margin if incorporating live edges into your design, and inspect flat surfaces thoroughly for signs of checking or internal casehardening.
- Drying: CIRAD Tropix notes that the drying rate is slow, with a medium risk of distortion and checking, as well as a risk of casehardening. Air drying prior to kiln drying is specifically recommended. Recommended kiln schedules start at 44 °C (111 °F) and top out at 60 °C (140 °F). Slabs must be uniformly dried to equilibrium before pouring epoxy.
- Machining: Massaranduba causes fairly high tool blunting and requires significant machine power. Use stellite-tipped saw blades and tungsten carbide cutting tools. For any mechanical joints, table leg brackets, or threaded fasteners, pre-boring is strictly necessary to prevent splitting.
- Sealing and Finishing: Due to its very high specific gravity and Class 4 impermeable heartwood, CIRAD Tropix notes that gluing must be executed strictly according to standard codes of practice. When pouring an epoxy river, thoroughly clean cut edges, apply a dedicated epoxy seal coat to lock down fine pores, and verify that the wood surface is scuffed properly to promote a durable mechanical bond.
Sources
Published October 30, 2026. Sources are linked in the text.
Header image: original graphic by BigEpoxy.com.
Staff note: While Massaranduba heartwood carries Class D durability against dry-wood borers without requiring chemical treatment, the CIRAD Tropix data notes that borer risks are limited specifically to the sapwood band (4 to 6 cm thick), making complete removal or meticulous inspection of live-edge sapwood critical before casting. (Source: CIRAD Tropix 7 technical sheet: Massaranduba.)