Teak Deck and Trim Care: Clean, Oil, Seal or Leave It Natural

Wet the teak and the surrounding gelcoat. Wash with a mild boat soap and a soft brush or sponge. On decks, work across the grain or in small circles with light pressure; scrubbing hard along the grain digs out the softer wood between the grain lines and leaves the seams sticking up. Rinse well. For a natural gray look, this is all you need, every few weeks or after a dirty trip.

A pressure washer rips out the soft wood between the hard grain lines, leaving a rough, grooved surface that holds dirt and water. It can also blow out deck seams. Use a hose on a gentle shower setting.

If the teak is still stained, black or blotchy after washing, step up one level at a time:

• A gentle teak soap or cleaner made for teak.
• A one-part teak cleaner (often oxalic acid based).
• A two-part cleaner (a caustic part one, then an acid part two) only for neglected, very dark teak. It works dramatically, but it removes the most wood. Don't make it a routine.

Always test on a small hidden spot first.

Wet down gelcoat, paint and metal next to the teak so the cleaner can't dry on them, and keep rinsing them while you work. Tape plastic over anodized aluminum frames, painted areas and chrome. Never let cleaner sit on the hull or drip into the water; collect runoff where you can and follow your marina's rules.

Wet the wood, apply the cleaner as the label says, and spread it evenly with a nylon pad or bronze wool. Let it work a few minutes without drying, then scrub lightly while still wet. Never use steel wool on a boat: the tiny steel bits rust and leave brown spots everywhere. Rinse thoroughly, brushing the grain clean.

Wet the wood. Brush part one onto a small area with a nylon brush (it dissolves natural bristles), wait the time on the label, and scrub gently. Then apply part two, which neutralizes part one and brightens the wood, until the color is even. Flush everything with lots of water. Mix exactly as the label says: too strong a mix can damage the wood and soften the black seam compound.

Before any oil or sealer, the wood must be completely dry, usually at least a full day of dry weather. Finishes put on damp teak peel, turn blotchy or trap mildew.

Light hand sanding with the grain can smooth raised, fuzzy grain on trim. Go easy: teak decks and veneers are thin, and screw plugs pop out once the wood around them is worn down. Never power sand a teak deck unless you have checked there is enough thickness left; that is a job to discuss with a teak specialist.

Tape off gelcoat and paint. Brush teak oil on with the grain. Wipe any drips or runs on fiberglass immediately with a rag dampened with mineral spirits; oil left on gelcoat leaves dark stains that are very hard to remove. Apply more coats as the wood soaks them up, wiping off any excess that pools, until the wood looks evenly saturated with a matte finish. Follow the can for thinning and drying times.

Follow the sealer maker's prep exactly. Some systems want bare, clean, dry wood; others want the teak oiled first, left to cure, and then wiped with a solvent before the sealer goes on. Apply thin coats, wipe off excess, and stop when you get an even matte finish.

Use a marine spar varnish with UV inhibitors, not a household polyurethane. Work in warm, dry, calm weather on wood that is clean, dry and smooth. Plan on many thin coats with light sanding in between, following the varnish label. Repair nicks quickly so water doesn't creep under the finish.

While the deck is clean, look at the black seam compound between planks. Lifting, cracked or missing seams, loose plugs, and planks that move or feel spongy can let water into the deck core below. Note them and plan repairs.

Rinse teak with fresh water after trips, especially in salt water. Wash gently every few weeks. Recoat oil or sealer when the color starts to fade or water stops beading. Log your cleaning and recoat dates in BoatMend.