A guest has left a wet glass on the marble bar top overnight. There is a dull white ring where the glass stood. You reach for the limescale spray you use in the shower — and that single decision would turn a mark into permanent damage. Knowing the surface comes before knowing the product.
Stone: marble, granite, limestone, onyx
Marble, limestone and onyx are calcium carbonate. They are acid-sensitive. Any acid — lemon, wine, vinegar, cola, descaler, many bathroom cleaners — reacts with the stone and etches it: a dull, physically eaten mark that no amount of polishing off will remove without professional refinishing.
- Clean stone with a pH-neutral stone cleaner and a damp microfibre; dry immediately.
- Blot acidic spills at once; rinse with clean water; dry.
- Granite is silicate-based and far more acid-tolerant, but its sealer is not — repeated acid or strong alkali strips the seal and lets stains soak in.
- Never use scouring pads or abrasive cream on polished stone; you will scratch the polish.
Metals: stainless steel and chrome
| Surface | Do | Avoid |
|---|---|---|
| Stainless steel | Wipe with the grain, freshwater rinse for salt, dedicated stainless cleaner/oil, buff dry | Chlorine bleach and chloride-based cleaners (pit and rust the steel), steel wool (embeds iron, causes 'tea staining') |
| Chrome / plated fittings | Warm water, mild detergent, soft cloth, dry buff | Abrasives and strong acids — the plating is thin and cannot be repaired |
| Brass / bronze (often lacquered) | Dust only unless told otherwise | Metal polish on lacquered brass — it strips the lacquer |
Salt is the enemy of every metal onboard. Freshwater rinse and dry is the single most valuable habit on exterior stainless.
Glass and mirrors
- Spray the cloth, not the glass, near electronics, timber frames and lacquer — overspray leaves runs and can damage adjacent finishes.
- Two-cloth method: one damp/glass-cleaner cloth, one dry buffing cloth. Work in one direction, then cross-direction, then edges.
- Ammonia-based glass cleaners are effective but attack some lacquers, plastics and tinted/coated glass. On yachts, an ammonia-free glass cleaner is the safe default.
- Mirrors: never let liquid run to the bottom edge — it wicks behind the silvering and causes black spotting.
Teak
- Exterior deck teak: wash across the grain (with the caulking, not along the grain) with a soft brush and plenty of salt or fresh water and a mild dedicated teak soap. Hard scrubbing along the grain erodes the soft grain and ruins the deck.
- Never use chlorine bleach or harsh two-part acid teak cleaners casually: they strip the wood's natural oils, raise the grain and can damage caulking and surrounding gelcoat.
- Interior teak / oiled or varnished timber: damp microfibre only, then dry. No solvent, no bleach, no all-purpose degreaser.
Onboard Notes
- Rings on marble are usually etching, not staining. Stop, report, do not experiment.
- Grit is the invisible scratcher — shake and rinse cloths, and always vacuum a stone floor before mopping.
- A yacht's stone is frequently thin, honed or book-matched slab: any repair is expensive and visible. When in doubt, water and a clean cloth, then ask.