Senegal Mahogany Slabs for Epoxy Tables: Stability and Build Guide

Senegal Mahogany in Wood and Epoxy Builds

Senegal mahogany (Khaya senegalensis) is an African hardwood belonging to the Meliaceae family. Renowned for fine furniture and interior joinery, this timber presents distinct physical and mechanical traits that make it a compelling subject for custom river tables and composite epoxy tabletops. Technical evaluations from the CIRAD Tropix programme provide precise baseline measurements that guide how woodworkers should prepare, machine, and stabilize these slabs prior to casting resin.

Property	CIRAD Tropix value	What it means / US units
Botanical name(s)	Khaya senegalensis
Colour / texture / grain	Red brown; texture medium; grain interlocked; interlocked grain slight
Specific gravity (12% MC)	0.78	about 48.7 lb/ft³; a 2-inch-thick slab weighs about 8.1 lb per sq ft
Monnin hardness (12% MC)	5.9	French hardness scale; higher = harder (not a Janka value)
Total tangential shrinkage	5.6 %	green to oven-dry
Total radial shrinkage	4.9 %	green to oven-dry
Ratio St/Sr	1.1	closer to 1 = less cupping tendency
Coefficient of volumetric shrinkage	0.43 % per % MC	volume change per 1% change in moisture content
Fibre saturation point	27 %
Thermal conductivity	0.26 W/(m·K)
Crushing strength (12% MC)	54 MPa	about 7,830 psi
Static bending strength (12% MC)	86 MPa	about 12,470 psi
Modulus of elasticity (12% MC)	11,650 MPa	about 1,690,000 psi
Decay (fungi) resistance	Durability class 3 – moderately durable
Termite resistance	Class S – susceptible
Dry-wood borer resistance	Class D – durable (sapwood demarcated, risk limited
Heartwood treatability	Class 3 – poorly permeable
Use class from natural durability	Class 2 – inside or under cover (dampness possible)
Drying	rate normal; distortion: slight risk; checking: slight risk; collapse: no known specific risk; casehardening: no known specific risk
Suggested kiln program temperatures	53–65 °C	about 127–149 °F
Machining	blunting normal; saw teeth: ordinary or alloy steel; cutting tools: ordinary
Nailing and screwing	Good
CITES status	Listed in CITES Appendix II with annotation #17 (African populations of Khaya species, including Khaya senegalensis, since 23.02.2023), per the BfN CITES tree list, status 05.03.2026. Annotation #17 covers logs, sawn wood, veneer sheets, plywood and transformed wood. (The CIRAD sheet says not listed; that note is out of date.)

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).

Visual Characteristics and Grain Figure

Freshly cut Senegal mahogany typically presents a pink brown tone that shifts to red brown with a purple tint over time, showing a distinct lustrous aspect on dressed surfaces. Its texture is medium, and while its sapwood ranges from 3 to 8 cm thick and is listed as clearly demarcated from the red-brown heartwood, practical grading notes indicate the sapwood line is not always clearly defined. The logs generally measure between 50 and 90 cm in diameter.

The grain is interlocked, typically classified as slight. When surfaced flat sawn or half quarter sawn, this grain structure can provide classic mahogany figure. However, woodworkers should note that the presence of interlocked grain demands targeted tool geometry during fabrication.

Weight, Hardness, and Mechanical Strength

At 12% moisture content, Senegal mahogany has an average specific gravity of 0.78, translating to a density of roughly 48.7 lb/ft³. For river table fabricators, a 2-inch-thick slab weighs approximately 8.1 lb per square foot. This solid heft gives finished tabletops exceptional stability and grounding.

On the French Monnin hardness scale, Senegal mahogany registers a 5.9 at 12% moisture content, placing it between fairly hard to hard. The Monnin scale differs from the American Janka test; it is an indentation metric where higher numbers denote harder wood, and it should never be converted directly to Janka values. Mechanically, the wood demonstrates a crushing strength of 54 MPa (about 7,830 psi), a static bending strength (modulus of rupture) of 86 MPa (about 12,470 psi), and a modulus of elasticity of 11,650 MPa (about 1,690,000 psi). This stiffness readily supports long table spans with minimal deflection.

Dimensional Stability and River Table Bondlines

Bonding cured epoxy resin to natural timber creates a composite interface where wood movement must be controlled. Senegal mahogany features a fibre saturation point of 27% and a coefficient of volumetric shrinkage of 0.43% per 1% change in moisture content.

Total shrinkage from green to oven-dry is 5.6% in the tangential direction and 4.9% in the radial direction. This yields an exceptionally balanced tangential-to-radial shrinkage ratio (St/Sr) of 1.1. In river table construction, a ratio this close to 1.0 indicates virtually uniform movement along both axes, drastically minimizing the tendency of slabs to cup, crown, or shear away from cured epoxy channels during minor indoor moisture fluctuations.

Drying Risks and Kiln Behavior

Senegal mahogany exhibits a normal drying rate with only slight risks of distortion and checking under standard drying schedules. There are no known specific risks of collapse or casehardening. However, CIRAD technical sheets caution that checking and distortion risks rise whenever slabs contain highly interlocked grain or tension wood. Suggested kiln drying temperatures run between 53 °C and 65 °C (about 127 °F to 149 °F).

Machining, Assembly, and Durability

Standard cutting tools and ordinary or alloy steel saw teeth handle the wood well, resulting in normal tool blunting. Because of a slight tendency toward woolliness and tearout around interlocked grain, tools must be kept very sharp, and a reduced cutting angle is required when planing or jointing. Nailing and screwing performance is rated as good.

The heartwood falls into durability class 3 (moderately durable against wood-decay fungi), class D for dry-wood borers (durable, with risk limited to sapwood), but class S (susceptible) to termites. Heartwood treatability is class 3 (poorly permeable). It meets natural durability requirements for Use Class 2 (interior or under cover, where dampness is possible), making it well-suited for high-class furniture, indoor staircases, panelling, and flooring.

CITES Protection Status

While historic documentation may list the species as unrestricted, African populations of Khaya species—including Khaya senegalensis—were listed in CITES Appendix II under annotation #17 on 23.02.2023 (confirmed in the BfN list status 05.03.2026). This regulatory listing covers logs, sawn wood, veneer sheets, plywood, and transformed wood, meaning legal import and trade documentation must be maintained when sourcing material.

Practical Pre-Pour Checklist for Senegal Mahogany

1. Verify Regulatory Documentation: Ensure all import permits and supply-chain invoices comply with CITES Appendix II annotation #17 requirements for transformed or sawn Khaya timber.
2. Confirm Equilibrium Moisture Content: Slabs must be fully dried below their 27% fibre saturation point down to interior baseline targets before resin contact.
3. Inspect for Tension Wood: Examine cut boards for wild or highly interlocked grain and tension zones that elevate checking or warp risks.
4. Adjust Tool Cutting Angles: Mill live edges and faces using sharp tooling at a reduced cutting angle to avoid woolly grain and tearout.
5. Plan Mechanical Joinery: Take advantage of the wood’s good screwing properties by pre-drilling mounting points into the 48.7 lb/ft³ slab for secure table base attachment.

Sources

• CIRAD Tropix 7 technical sheet: Senegal mahogany
• CIRAD Tropix 7 technical sheets (index)
• German Federal Agency for Nature Conservation (BfN): List of tree species protected under CITES and Regulation (EC) 338/97, status 05.03.2026

Published October 30, 2026. Sources are linked in the text.

Header image: original graphic by BigEpoxy.com.