Rust on a watch, and what can be done

Where the rust is decides what to do. Light rust on the outside, on a steel bracelet, between its links, on a buckle or a spring bar, can usually be cleaned off or the part replaced, and the watch is no worse for it. Rust inside the case, on the dial, the hands or the movement, means water has got in. That watch should stop being worn and go to a watchmaker promptly, because its steel parts keep rusting while the moisture stays, and every part that rusts too far has to be replaced. In neither case is it time for acids, abrasives or rust removers: they harm finishes, plating and seals far more readily than they help.

Why stainless steel rusts

Stainless steel resists corrosion because of a thin film that forms on its surface, but it is not immune. Where sweat, salt water and dirt sit for a long time, in the narrow gaps between bracelet links, under a clasp, around a spring bar, that film breaks down and rust appears. Seiko’s care guidance for watch bands says as much: even stainless steel bracelets rust where sweat and dirt build up between the links. Titanium bracelets can rust too where their pins are steel, and Seiko warns that a pin rusted far enough can work loose, so that the case comes away from the bracelet or the clasp will not open. Plated cases, common on vintage watches, are different again: once the plating wears through, the base metal underneath corrodes much as ordinary metal would.

Rust on the outside

Surface rust on a stainless steel bracelet is the most common kind, and the gentlest cleaning is usually enough. Seiko’s method is to wipe the bracelet with a soft cloth whenever it is damp; if marks remain, to rinse it with water and work the gaps between the links with a soft toothbrush, the watch head wrapped to keep it dry; and then to dry every gap thoroughly. Taking the bracelet off the case first is safer still, and keeps water well away from the crown.

• Do not use vinegar or other acids, scouring pads or abrasive papers. They dull brushed and polished surfaces, strip plating, and leave marks that are harder to put right than the rust was.
• Replace rusted spring bars and bracelet pins rather than cleaning them. They are what holds the watch to the wrist.
• Leave rust on a plated surface, or around the crown, the case back or the crystal, to a watchmaker. Around the openings of the case, it can mean the seals there are failing.

Where rust has eaten into the metal and left pits, cleaning removes the rust but not the pits it has left behind.

Rust inside the case

Rust spots on the dial or hands, mist under the crystal that does not clear, or a watch that stops after getting wet all mean moisture is inside. Citizen’s advice on water resistance is the right advice: stop using the watch and have it repaired straight away. Do not open it, and do not try to dry it with heat, which can harm an acrylic crystal and the seals and does not reach the water inside the movement. How water gets in, and how the seals that keep it out age, is set out in when watch gaskets need replacing.

Inside, rust does its damage on steel: the pivots and pinions of the gear train, the screws, the parts of the winding and setting mechanism and of the calendar, and in bad cases the mainspring or the hairspring. Rust roughens and pits a pivot, and a pitted pivot wears its jewel and drags. Cleaning lifts loose rust but cannot restore a pitted surface, so a rusted part is usually replaced, or, where no replacement can be found, repaired or made. That is why water damage costs more than an ordinary service, as what a watch service costs explains, and why acting within days rather than weeks saves parts.

What the repair involves

The watch is taken apart completely, every part is inspected, and the rusted ones are listed. The estimate says which can be cleaned and which must be replaced, and whether replacements can be found: for a current calibre they usually can, while an old or rare one may take a search. The movement is then cleaned, rebuilt with the new parts, lubricated and regulated, and the case gets new gaskets and a pressure test before it goes near water again. The dial and hands are a separate matter. Rust marks on a dial are often permanent, and what can be done for one is set out in what can be done for a worn watch dial.

At Viattori, the assessment and the estimate are free and nothing is done until you approve the estimate. A full mechanical service takes two to four weeks; a restoration can take longer when parts have to be sourced or made, and the estimate gives a completion date in good faith.

Keeping rust away

• Rinse a water-resistant watch in fresh water after the sea or a pool, with the crown pushed in or screwed down, then dry it, the gaps of the bracelet included.
• Wipe off sweat after exercise or a hot day, and dry a watch that has been out in the rain.
• Do not use the crown or the pushers while the watch is wet, and never wear a screw-down crown unscrewed.
• Have the seals checked and the case pressure-tested at each service, and whenever the case has been opened.
• Store the watch somewhere dry, not in a bathroom.

Questions

Can a rusted watch be repaired?

Usually, depending on where the rust is and how long it has been there. Rust on a bracelet or buckle can often be cleaned, or the part replaced. Rust inside means taking the movement apart and replacing the rusted parts, which is more work the longer the moisture stayed in.

Does vinegar remove rust from a watch?

It can lift light rust, but it is an acid: it attacks plating, dulls finishes and leaves residue in the gaps of a bracelet, where corrosion starts again. Water, a soft brush and thorough drying are safer, and a rusted spring bar or pin is better replaced.

Why is my stainless steel watch rusting?

Stainless steel resists rust but is not immune. Where sweat, salt and dirt stay for a long time, in the gaps between bracelet links or around a spring bar, its protective surface breaks down and rust forms. Regular rinsing and drying prevents most of it.

What should I do if water got inside my watch?

Stop wearing it and have it seen as soon as you can. Do not open it or dry it with heat. Steel parts inside keep rusting while the moisture stays, so the sooner it is opened, dried and serviced, the more of the movement can be saved.