Using Curupixa in Epoxy River Tables
Curupixa is a Latin American hardwood harvested from several species in the Sapotaceae family, primarily Micropholis gardnerianum, Micropholis melinoniana, Micropholis venulosa, and other Micropholis species. Known for its fine texture and uniform straight grain, it is commercially utilized in fine cabinetwork and furniture. When pairing wood slabs with epoxy resin, understanding physical movement, tool requirements, and environmental durability is critical. The technical data below is drawn directly from the CIRAD Tropix technical sheet for Curupixa.
| Property | CIRAD Tropix value | What it means / US units |
|---|---|---|
| Botanical name(s) | Micropholis gardnerianum, Micropholis melinoniana, Micropholis venulosa, Micropholis p.p. | |
| Colour / texture / grain | Light brown; texture fine; grain straight; interlocked grain absent | |
| Specific gravity (12% MC) | 0.75 | about 46.8 lb/ft³; a 2-inch-thick slab weighs about 7.8 lb per sq ft |
| Monnin hardness (12% MC) | 4.3 | French hardness scale; higher = harder (not a Janka value) |
| Total tangential shrinkage | 7.9 % | green to oven-dry |
| Total radial shrinkage | 4.8 % | green to oven-dry |
| Ratio St/Sr | 1.6 | closer to 1 = less cupping tendency |
| Coefficient of volumetric shrinkage | 0.51 % per % MC | volume change per 1% change in moisture content |
| Fibre saturation point | 30 % | |
| Thermal conductivity | 0.25 W/(m·K) | |
| Crushing strength (12% MC) | 59 MPa | about 8,560 psi |
| Static bending strength (12% MC) | 109 MPa | about 15,810 psi |
| Modulus of elasticity (12% MC) | 17,300 MPa | about 2,509,000 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 2 – moderately permeable | |
| Use class from natural durability | Class 1 – inside (no dampness) | |
| Drying | rate rapid to normal; distortion: slight risk; checking: slight risk; collapse: no known specific risk; casehardening: no known specific risk | |
| Suggested kiln program temperatures | 45–65 °C | about 113–149 °F |
| Machining | blunting fairly high; saw teeth: stellite-tipped; cutting tools: tungsten carbide | |
| Nailing and screwing | Good | |
| CITES status | This species is not listed in the CITES Appendices (Washington Convention 2025). Notes. Several species with variable properties are commercialized under the name CURUPIXA. |
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).
What does Curupixa look like, and how is its grain structured?
According to CIRAD Tropix, Curupixa features a light brown reference color, though coloration is noted to be variable, ranging from yellow-brown to grey-brown, sometimes showing pink or purplish glints. The sapwood is not demarcated from the heartwood. It exhibits a fine texture and a straight grain, with interlocked grain completely absent. Because interlocked grain is absent and the grain runs straight, the wood presents a clean, predictable visual face that pairs evenly with clear or tinted resin pours.
How heavy and hard is Curupixa?
Curupixa has an average specific gravity of 0.75 at 12% moisture content. In practical shop terms, this translates to a density of about 46.8 lb/ft³, meaning a standard 2-inch-thick tabletop slab weighs approximately 7.8 lb per square foot. In terms of hardness, CIRAD Tropix records a Monnin hardness of 4.3 at 12% moisture content. The Monnin scale is an empirical French hardness test where higher numbers indicate harder timber; it should not be confused with or converted to the American Janka test. At 4.3 Monnin, Curupixa offers solid surface resistance suitable for daily-use furniture, indoor staircases, and flooring.
How stable is Curupixa next to a cured epoxy river?
Epoxy cures into a rigid plastic that does not expand or contract with seasonal ambient humidity. Placing wood with high shrinkage against an epoxy river can cause shear strain along the glue line. Curupixa has a total tangential shrinkage of 7.9% and a total radial shrinkage of 4.8%, yielding a tangential-to-radial shrinkage ratio (St/Sr) of 1.6. Its coefficient of volumetric shrinkage is 0.51% per 1% change in moisture content, with a fiber saturation point of 30%. Because the St/Sr ratio is relatively modest (1.6), the wood has a lower tendency toward severe cupping or distortion across flat surfaces, provided the timber is thoroughly dried before resin casting.
What are the drying characteristics and risk factors?
CIRAD Tropix rates the drying rate of Curupixa as rapid to normal. During the drying process, there is a slight risk of distortion and a slight risk of checking. There is no known specific risk of collapse or casehardening. When kiln-drying boards or slabs, suggested drying program temperatures range from 45 °C (113 °F) during the initial phases up to 65 °C (149 °F) in the final drying stages. Ensuring the wood is stabilized to internal indoor conditions prevents later stress cracking along bonded edges.
How does Curupixa machine, and what tooling is needed?
Working Curupixa requires consideration of tool wear. The blunting effect on cutting edges is fairly high. CIRAD notes that this species group has variable silica content depending on the specific botanical species. Consequently, stellite-tipped saw teeth are recommended for breakdown and sawing, while tungsten carbide cutting tools should be used for shaping, surfacing, and routing. In standard assembly, nailing and screwing properties are rated as good. For epoxy bonding, follow the resin manufacturer’s technical instructions regarding clean, dust-free mechanical surface preparation.
What is the natural durability of Curupixa in finished tables?
Heartwood durability against xylophagous fungi is classified as Durability class 4 – poorly durable. It is classified as Class S (susceptible) to dry wood borers across all the wood, and Class S (susceptible) to termites. The heartwood is moderately permeable (Class 2 treatability). As a result of its natural durability, its recommended use class is Class 1 – inside (no dampness). It requires appropriate preservative treatment if subjected to dry wood borers or temporary humidification, and its use is not recommended in cases of permanent humidification. Therefore, Curupixa is strictly intended for dry, climate-controlled interior furniture, such as dining tables, desks, and cabinetwork.
Is Curupixa subject to international trade restrictions?
Curupixa is not listed in the CITES Appendices (Washington Convention 2025). Builders should note, however, that commercial lumber sold under the name Curupixa includes several different Micropholis species whose properties may exhibit variation across origins.
Sources
Published October 30, 2026. Sources are linked in the text.
Header image: original graphic by BigEpoxy.com.
Staff note: Because CIRAD records a fairly high blunting effect linked to variable silica content in Micropholis species, keep carbide surfacing cutters sharp and clean dust off slab faces thoroughly before sealing, as residual silica and wood dust can foul surface adhesion. (Source: CIRAD Tropix 7 technical sheet: Curupixa.)