Gaboon Ebony — Density, Movement, Workability & Cost

Seal the ends of a fresh gaboon ebony (Diospyros crassiflora) blank the day it arrives, or you'll very likely lose it — this is the blackest wood in commercial trade and also one of the hardest to season, and a thick piece left unsealed for even a week routinely develops end checks that ruin it before it's ever touched a tool.

Extreme density, extreme drying risk

At 60 lb/ft³ and 3,080 lbf on the Janka scale, gaboon ebony is exceptionally dense and hard, and its 20% volumetric shrinkage — the highest total shrinkage figure in this site's entire dataset — is exactly why seasoning it is a genuine skill rather than a formality. Once dry, it machines to a surface needing almost no abrasive at all, turns superbly, and blunts every cutting edge it meets, carbide included.

The movement number behind the seasoning warning

Radial shrinkage of 9.2% is itself the highest of any species this site tracks, and paired with 10.8% tangential it gives a 1.2 ratio — nearly balanced, which sounds reassuring but actually means both directions move a great deal, with no "safe" quartersawn escape route the way a lopsided ratio would offer. A small 3"-wide fingerboard blank moving from a 9% moisture content to a dry 6% loses about 0.032" (0.8mm) across its width — modest in absolute terms at this scale, though the wood movement calculator shows how quickly that scales up on a wider piece. A 1/2"-thick, 3"-wide, 18"-long blank weighs about 0.94 lb; the wood weight calculator covers other small-blank sizes.

Gluing an oily surface, and a finish that needs almost nothing

The wood is oily and dense enough that a fresh acetone degrease immediately before gluing genuinely matters, and epoxy is the more reliable adhesive choice over PVA for anything structural. Most finishers reach for nothing more than wax or a thin oil — the wood burnishes to a natural gloss under a scraper that a film finish struggles to improve on anyway.

Durability, cost, and the ebony trade's own scarcity

The heartwood is very durable, though the pale sapwood carries none of that resistance and is typically discarded or used for lesser purposes. At roughly $130 per board foot, gaboon ebony is among the most expensive species this site tracks. Guitar fingerboards, piano keys, inlay, knife scales, and turnery round out its markets. It carries an IUCN Endangered rating and is heavily depleted across its range — unlike the Madagascan ebony species, African Diospyros aren't CITES-listed, which makes careful, deliberate sourcing a buyer's own responsibility rather than something regulation enforces automatically.

Living with a wood this difficult to season

Experienced turners and instrument builders treat gaboon ebony less like ordinary lumber and more like a material requiring its own specific handling protocol: seal ends immediately, store it away from direct heat or drafts, and expect a genuinely slow drying schedule for anything beyond fingerboard-thin stock. Rushing any part of that process is the single most common cause of losing an expensive blank to checking.

What people actually ask about gaboon ebony

Does end-sealing wax work as well as a dedicated commercial end-grain sealer for a gaboon ebony blank, or is the product choice actually important here? A quality dedicated sealer, applied thickly enough to genuinely slow vapour loss, outperforms a thin coat of general-purpose wax on a species this shrinkage-prone — given how expensive a lost blank is, most experienced turners treat the sealer choice as worth getting right rather than improvising with whatever's on hand.

Is all "ebony" sold commercially actually this same species? No — "ebony" is a common name applied to several distinct Diospyros species from different regions, including this African species and the separately regulated Madagascan and East Indian species, each with somewhat different properties and legal status.

Does gaboon ebony sapwood at least season more easily than the notoriously checking-prone heartwood, given it's less dense? No — the sapwood carries much the same high shrinkage figures as the heartwood, since both come from the same tree and the same underlying cell structure, so a sapwood-heavy blank still demands the same careful, slow drying discipline despite offering none of the heartwood's value once it's dry.

FPL's Table 4-4 (Wood Handbook, FPL-GTR-190, 2010) lists this species as "Ebony, African" and provides the shrinkage figures used here; The Wood Database's 12%-moisture-content testing gave the density and Janka hardness.