Sulawesi yards build wooden vessels mainly from ulin (ironwood) for keels, bitti (Vitex cofassus) for structure and planking, and teak for decks and joinery — and every stick must carry SVLK legality paperwork. This page covers species roles, seasoning, supplier verification, and the marine materials that arrive with the timber.
Answer first: which timbers Sulawesi yards actually use, and how to keep the paperwork legal
Three species do most of the structural work in a traditional Sulawesi build. Ulin — ironwood, Eusideroxylon zwageri — is the near-universal choice for keels and high-wear structure because of its extreme density and rot resistance. Bitti — Vitex cofassus, a species endemic to Sulawesi — is the traditional structural wood of South Sulawesi boatbuilding, prized for frames and planking because it balances strength, workability and marine durability; historically it was also the keel timber before ironwood became common. Teak (Tectona grandis) carries the decks, superstructure and visible joinery thanks to its natural oils and dimensional stability. Legality runs through Indonesia’s SVLK timber-legality assurance system: a legitimate supplier can show SVLK certification and, for export contexts, V-Legal documentation. No paperwork, no purchase — that rule protects both the forest and your vessel’s future registration and resale.
Species table: ulin (ironwood), bitti, teak, meranti and alternatives
| Species | Role in the hull | Durability class | Indicative USD band |
|---|---|---|---|
| Ulin / ironwood (Eusideroxylon zwageri) | Keel, stem, sternpost, high-wear structure | Very high — dense, marine-borer resistant | Highest-priced structural stock; quoted per m³ on availability, legality paperwork adds cost and lead time |
| Bitti (Vitex cofassus) | Frames, planking, keel in traditional practice | High — proven structural properties in South Sulawesi community-forest stock | Mid-to-high; the workhorse of heritage-coast builds |
| Teak / jati (Tectona grandis) | Decks, deckhouse, interior joinery, finishing | High — natural oils, stable, weathers well | Plantation teak quoted by grade; clear vertical-grain deck stock commands the premium |
| Meranti (Shorea spp.) & kandole | Non-critical planking, interior parts, temporary works | Moderate — below teak/bitti/ulin | Lowest band; never acceptable for keel or frames |
Exact per-cubic-metre prices move with legality class, girth, and season; the desk quotes current numbers in USD at sourcing time rather than publishing figures that would be stale in a quarter.
Moisture content & seasoning timeframes in the Sulawesi climate
Air-drying in the humid Sulawesi climate is slow and rarely takes large structural baulks below roughly 18–20% moisture content; boatbuilding practice accepts higher moisture in massive keel timbers, while planking and joinery stock should be seasoned further — months of stickered air-drying, or kiln time where available — before it is worked. What matters contractually is that the timber budget includes seasoning time: green planking driven straight onto frames is a defect factory. Seasoning schedules are one of the milestone items checked during in-build survey inspections.
SVLK legality: verifying suppliers and traceability from log to hull
Documents to demand
Ask every supplier for: current SVLK certificate (check the certificate body and expiry), transport documents matching the physical stock (species, volume, origin), and for export scenarios the V-Legal / FLEGT-linked documentation. Cross-check that species and volumes on paper match what is stacked in front of you — mismatched paperwork is the classic laundering pattern.
Red flags for illegally logged stock
Warning signs: ulin offered cheap and fast with “flexible” paperwork; suppliers who cannot name the concession or community forest of origin; stock that arrives at night without transport documents; prices dramatically below the market for protected-species-adjacent timber. Illegal stock exposes the owner to confiscation risk and poisons later registration, class entry and resale — the discount is never worth it. The desk sources only against verifiable SVLK chains, which is also what makes a future resale valuation defensible.
Beyond timber: fastenings, caulking, sheathing, engines & electrics supply
Silicon bronze & galvanised fastenings
Traditional builds used hardwood trunnels and galvanised iron; modern charter-spec builds specify silicon bronze or hot-dip galvanised fastenings by zone — bronze below the waterline where budget allows, galvanised elsewhere, never mixed carelessly in contact (galvanic corrosion). Fastener schedules are written into the build contract and checked at survey.
Epoxy and copper sheathing options
Below-waterline protection choices include traditional caulked-and-painted finish, epoxy sheathing over the planking, and copper-based antifouling systems. Epoxy sheathing adds abrasion protection and reduces leak paths but must go onto adequately dry timber; copper sheathing is a heritage method still used on some working hulls. The right choice depends on operating profile and haul-out access, and it links directly to the maintenance and refit plan.
The desk also coordinates the non-timber supply chain: marine plywood, caulking cotton and compounds, paints, shaft and propeller sets, tanks, and the engine and electrical packages discussed in the custom build programme.
Request a sourcing quote (USD)
Tell the desk what the build needs — species, dimensions, volumes, delivery point — and you receive a current USD quotation with legality documentation listed line by line. Timber sourcing can be contracted standalone or as part of a supervised build under PT Komodo Galangan Nusantara.
Frequently asked questions
What timber species are typically used for phinisi hulls and decks in Sulawesi?
Keels and primary structure: ulin (ironwood) and bitti. Frames and planking: bitti, with teak or selected hardwoods for planking on higher-spec builds. Decks, deckhouse and joinery: teak. Meranti and similar secondary hardwoods appear only in non-critical parts.
How do I check that a timber supplier has valid SVLK certification?
Ask for the SVLK certificate itself, verify the issuing certification body and expiry date, and confirm the certificate holder matches the entity selling to you. Then check that transport documents accompanying each delivery state species, volume and origin consistent with the certificate. The desk performs this verification on every sourcing engagement.
What moisture content should boatbuilding timber be dried to before construction?
Planking and joinery stock should be seasoned as far as the tropical climate allows — air-dried in stickered stacks for months toward roughly 18–20% moisture content, lower with kiln assistance. Massive keel baulks are traditionally worked at higher moisture. The critical discipline is scheduled seasoning time in the build plan, verified before planking begins.
How do I avoid illegally logged timber when sourcing boatbuilding materials in Sulawesi?
Buy only against a complete SVLK chain: certificate, matching transport documents, and a named origin (concession or community forest). Refuse stock that is suspiciously cheap, undocumented, or delivered irregularly. Illegal timber risks confiscation and permanently damages the vessel’s registration and resale position.
Bagaimana memastikan ulin atau bitti yang dipakai legal dan bukan dari sumber yang dilarang?
Minta sertifikat SVLK pemasok, cocokkan dokumen angkutan kayu dengan fisik stok (jenis, volume, asal), dan pastikan asalnya dari konsesi atau hutan rakyat yang bisa disebut namanya. Ulin murah tanpa dokumen hampir pasti bermasalah — tolak. Desk kami hanya membeli lewat rantai SVLK yang bisa diverifikasi.
Material dan finishing apa yang paling awet di lingkungan tropis: teak, meranti, ironwood, atau komposit?
Kombinasi lebih penting daripada satu material: ulin untuk lunas dan struktur bawah air; bitti/teak untuk papan kulit, dek, dan superstruktur; meranti hanya untuk bagian non-kritis; komposit (sheathing epoxy/FRP) sebagai pelindung tambahan di area abrasi. Finishing paling awet adalah sistem cat atau varnish maritim berkualitas dengan siklus perawatan rutin — teak bertahan baik dengan oiling maupun clear coat asal dirawat konsisten.
Source timber the legal way: WhatsApp +62 811-3823-875 · sales@komodoluxury.com — quotations in USD with SVLK documentation listed.
From the journal
- Best Woods for Phinisi Keels, Frames, Planking and Decks
- Legal Boatbuilding Timber in Sulawesi: SVLK, Species and Sources
- How SVLK Timber Rules Are Changing Sulawesi Boatbuilding
To see which coast works which species, start from the island register of Sulawesi boatyards.