Wooden Hull Maintenance Calendar: Antifouling, Caulking and Re-Planking
An actively chartered wooden phinisi should be hauled out annually for hull inspection, antifouling and caulking checks; re-planking belongs to major refit cycles, not the annual calendar. Plan the haul-out into the December–March low season, when Komodo’s main April–November sailing season is closed. As a planning estimate — not a published standard — budget roughly 5–10% of build cost per year for routine maintenance.
- Monthly: bilges, seams, deck leaks, anodes visually checked, systems logged.
- Quarterly: tender and dive gear service, rig inspection, deck caulking review.
- Annually: haul-out, antifouling, anodes, caulking survey, shaft and stern gear.
- Every 3–5 years: major refit items — significant re-caulking, deck renewal, repower planning.
A wooden hull is not high-maintenance so much as unforgiving of neglect. Small problems — a deck leak, a soft frame head, a tired anode — are cheap in month one and expensive in year three. This calendar is the framework we use for charter vessels working the Komodo and Raja Ampat seasons.
What is the maintenance calendar?
| Interval | Tasks | Why |
|---|---|---|
| Weekly / per charter | Bilge check, deck wash-down with fresh water, freshwater flush of systems, visual seam check | Salt and standing fresh water are the two agents that start rot |
| Monthly | Engine and genset service items, battery and charging check, anode condition, deck leak trace, seacock exercise | Catches the small failures before they become charter-cancelling ones |
| Quarterly | Rig and standing rigging inspection, tender and davit service, dive compressor service, life-saving equipment check | Safety equipment expires on a calendar, not on usage |
| Annually (haul-out) | Hull inspection, antifouling, anode renewal, caulking survey and localised re-caulking, shaft and stern gear, rudder bearings, propeller service, through-hull inspection | The only reliable way to see what is happening below the waterline |
| Every 3–5 years | Extensive re-caulking, deck renewal or overlay, interior refresh, repower assessment, tank cleaning and inspection | These are refit-scale projects with refit-scale budgets |
When should a Komodo boat haul out?
December to March. Komodo’s main sailing season runs April to November with the most settled conditions June to September, and the wet months are when the fleet does its yard work. There is a second consideration if you also work Raja Ampat, where the prime liveaboard season is roughly October to April — boats that run both destinations have a genuinely tight window and need the yard slot booked far in advance.
Align the haul-out with class survey requirements so you are not paying to lift the boat twice. The interaction between survey cycle and maintenance calendar is covered in our dry dock, haul-out and annual maintenance programme.
How does antifouling work on a wooden hull?
The principle is the same as any hull — a coating that discourages fouling growth — but two things differ. First, preparation matters more: aggressive stripping on a wooden hull can damage caulking and plank surfaces, so surface preparation should be planned rather than handed to whoever is free. Second, tropical fouling is fast, so intervals that work in temperate waters are optimistic in Indonesia.
Anodes go on at the same time. Sacrificial anodes protect the shaft, propeller, rudder fittings and through-hulls, and they are consumed — a boat with heavily wasted anodes has been eating its own hardware. Check them at every haul-out and inspect them in the water between times.
What is caulking and how often does it need attention?
Caulking is the fibrous material driven into the seams between hull planks and sealed, which keeps the hull watertight while allowing the timber to move. On a well-built hull with properly seasoned timber, caulking lasts years; on a hull built from timber that was pulled before it finished seasoning — heavy ironwood sections may need up to twelve months of drying — seams start working early and demand attention sooner.
At each annual haul-out the seams are surveyed and any that have hardened, lifted or opened are cut out and re-caulked locally. Full re-caulking of a hull is a refit event. If a boat needs full re-caulking every couple of years, the underlying problem is structural or the timber was wrong — investigate rather than repeat the repair. Timber quality and its consequences are covered in the phinisi timber guide.
When does re-planking become necessary?
When a plank has rot, borer damage or mechanical damage beyond local repair, or when repeated caulking failure in the same area shows the plank edge has degraded. Signals to watch:
- Persistent water ingress in one area despite re-caulking.
- Soft timber found by a surveyor’s probe or moisture readings well above the surrounding planking.
- Fastening failure — planks moving against frames.
- Visible borer tracks or fungal staining, especially near the waterline and at hood ends.
Ironwood below the waterline resists both rot and borers, which is precisely why it goes there; problems more often appear above the waterline and at the deck edge where fresh water lingers. Scope, sequence and cost for this level of work sit in phinisi refit and restoration.
What should maintenance cost per year?
The industry rule of thumb is roughly 5–10% of build cost per year for routine maintenance. Treat it as an estimate rather than a benchmark — we could not find an authoritative published schedule for Indonesian wooden charter vessels, and actual costs depend on build quality, operating intensity and how disciplined the crew are between haul-outs.
What that means in a business plan: on published Komodo planning benchmarks a mid-size luxury phinisi grosses about IDR 3.6 billion a year against IDR 1.5–2.0 billion of operating cost, of which maintenance is a substantial share. Owners who model revenue without a proper maintenance line arrive at returns that do not survive contact with year three — the full picture is in phinisi charter revenue model: 2027 benchmarks.
Frequently asked questions
How often should a wooden boat be hauled out?
Annually for an actively chartered hull in tropical waters — hull inspection, antifouling, anodes and a caulking survey. Boats working hard seasons in both Komodo and Raja Ampat should treat this as fixed, not flexible.
How long does antifouling last in Indonesia?
Less than the same coating would last in temperate water — tropical fouling is fast. Plan on the annual haul-out cycle and inspect in the water between times rather than assuming a stated interval.
How often does a phinisi need re-caulking?
Localised re-caulking is normal at annual haul-outs. Full re-caulking is a refit-cycle event. Frequent full re-caulking indicates a timber or structural problem that needs diagnosis, not repetition.
What does phinisi maintenance cost per year?
As a planning estimate, roughly 5–10% of build cost annually for routine work, excluding major refit items. Verify against actual quotes from your yard — this is a rule of thumb, not a published figure.
Can maintenance be done in Labuan Bajo?
Routine work and many repairs, yes. Significant hull work is often better done where the skills and timber are — the Bulukumba yards — which means factoring a delivery passage into the refit plan. See delivery voyage, sea trials and crew handover.
Talk to the team
Komodo Boat Construction is operated by Komodo Luxury, part of Juara Holding Group, working Komodo waters since 2015. Send us your vessel details and we will build a maintenance calendar around your charter season rather than against it.
WhatsApp: +62 811 3823 875 · Email: sales@komodoluxury.com