Merkus Pine Slabs and Boards for Wood and Epoxy Tabletops
Merkus pine (Pinus merkusii) is a softwood native to Asia-Oceania that yields dense, distinctively marked timber. According to the CIRAD Tropix technical sheet, the wood features a light brown heartwood marked with dark red veins and a medium texture with straight grain and no interlocked grain. Live edge slabs feature a clearly demarcated sapwood band measuring from 2 to 5 cm thick. For tabletop builders looking for dramatic contrast alongside tinted or clear epoxy resins, the dark red veins provide a distinctive aesthetic rarely found in typical commercial pines.
Mature log diameters range from 60 to 80 cm, providing practical widths for bookmatched river tables, multi-board dining surfaces, or single-slab console tops. In terms of weight, Merkus pine is substantially denser than common North American softwoods. The CIRAD Tropix sheet records an average specific gravity of 0.73 at 12% moisture content, translating to about 45.6 lb/ft³. A 2-inch-thick tabletop slab weighs approximately 7.6 lb per sq ft. On the Monnin hardness test—a French indentation scale where higher numbers reflect greater hardness—Merkus pine records a value of 3.2. CIRAD notes that its hardness ranges from fairly hard to hard, though mechanical properties can vary based on the tree’s age and the plantation site.
Dimensional Stability and Shrinkage Next to Epoxy
When bonding timber to cured epoxy, dimensional stability is vital to protect against joint stress and bond-line separation. Merkus pine exhibits a total tangential shrinkage of 8.0% and a total radial shrinkage of 5.0% from green to oven-dry, producing an St/Sr ratio of 1.6. Its coefficient of volumetric shrinkage is 0.45% per 1% change in moisture content, with a fiber saturation point of 32%. A shrinkage ratio of 1.6 shows moderate cupping resistance, but the total movement means boards must be thoroughly dried to target interior equilibrium moisture levels before casting deep epoxy pours.
Drying behavior is categorized as rapid. The CIRAD sheet indicates no risk or very slight risk of distortion, a slight risk of checking, and no known specific risk of collapse or casehardening. However, builders must note two key vulnerabilities: a risk of blue stain and a tendency for resin exudation. Recommended kiln schedules reach operating temperatures between 70 °C and 80 °C (about 158–176 °F). Proper heat scheduling is essential to manage moisture without driving excessive pitch flow.
Machining, Assembly, and Durability
In the workshop, Merkus pine offers normal blunting on ordinary or alloy steel saw teeth and cutting tools. However, the wood contains numerous resin canals, and CIRAD warns of the risk of tools clogging due to resin. Keeping cutters clean helps avoid localized burning during edge preparation. The species exhibits good nailing and screwing properties. Under mechanical testing at 12% moisture content, it demonstrates a static bending strength of 90 MPa (about 13,050 psi), a modulus of elasticity of 16,370 MPa (about 2,374,000 psi), and a crushing strength of 51 MPa (about 7,400 psi).
Natural resistance to biological degradation is low. Merkus pine heartwood falls into durability class 4 (poorly durable) against fungi, is classed as Class S (susceptible) to termites, and Class S (susceptible across all wood) to dry-wood borers. Its natural durability restricts it to use class 1, designating interior environments free of dampness. Consequently, Merkus pine epoxy river tables are best reserved for climate-controlled indoor living and dining spaces. The species is not listed in the CITES Appendices (Washington Convention 2025).
| Property | CIRAD Tropix value | What it means / US units |
|---|---|---|
| Botanical name(s) | Pinus merkusii | |
| Other trade names | Merkus-pine, Pinus merkusii | |
| Colour / texture / grain | Light brown; texture medium; grain straight; interlocked grain absent | |
| 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) | 3.2 | French hardness scale; higher = harder (not a Janka value) |
| Total tangential shrinkage | 8.0 % | green to oven-dry |
| Total radial shrinkage | 5.0 % | green to oven-dry |
| Ratio St/Sr | 1.6 | closer to 1 = less cupping tendency |
| Coefficient of volumetric shrinkage | 0.45 % per % MC | volume change per 1% change in moisture content |
| Fibre saturation point | 32 % | |
| Thermal conductivity | 0.24 W/(m·K) | |
| Crushing strength (12% MC) | 51 MPa | about 7,400 psi |
| Static bending strength (12% MC) | 90 MPa | about 13,050 psi |
| Modulus of elasticity (12% MC) | 16,370 MPa | about 2,374,000 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; distortion: no risk or very slight risk; checking: slight risk; collapse: no known specific risk; casehardening: no known specific risk | |
| Suggested kiln program temperatures | 70–80 °C | about 158–176 °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). Notes. This species can be found at altitudes between 150 m and 650 m. |
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).
Frequently Asked Questions
What is the Monnin hardness of Merkus pine, and how is it measured?
Merkus pine has an average Monnin hardness rating of 3.2 at 12% moisture content. Monnin hardness is a French standardized scale derived from cylinder indentation where higher values designate harder timbers. It is not equivalent to the American Janka hardness scale and should not be directly converted to it.
How wide are Merkus pine slabs for river table builds?
CIRAD records log diameters ranging from 60 to 80 cm. Slabs cut from these logs are well-suited for two-board river dining tables, desks, and single-piece accent tops, with sapwood thickness spanning 2 to 5 cm along the edges.
How does resin exudation affect epoxy bonding on Merkus pine?
The wood contains numerous resin canals and presents a recognized risk of resin exudation and tool clogging. Surface pitch can interfere with adhesives and finishes; thorough drying and solvent cleaning of joint edges prior to resin casting are sensible workshop measures.
What is the natural durability of Merkus pine heartwood?
Heartwood is rated durability class 4 (poorly durable) against decay fungi and is susceptible (Class S) to both dry-wood borers and termites. Its natural durability provides for use class 1 (interior without dampness), making it unsuited for untreated exterior exposure.
Is Merkus pine subject to trade restrictions under CITES?
No. Merkus pine (Pinus merkusii) is not listed in the CITES Appendices under the Washington Convention 2025 updates, meaning international trade in this timber is not governed by CITES export controls.
Sources
Published October 31, 2026. Sources are linked in the text.
Header image: original graphic by BigEpoxy.com.
Staff note: The CIRAD Tropix data sheet notes that freshly harvested Merkus pine must be sawn quickly due to rapid blue stain development, and if air drying is undertaken, the timber requires storage under cover with piling in a ‘V’ shape. (Source: CIRAD Tropix 7 technical sheet: Merkus pine.)