Locks between two lagoons

Most coastal towns have salt in the air. Torrevieja has rather more of it, and from more than one direction, and after a few years you can read it in the locks.

The geography, briefly

The town sits on a narrow strip between the Mediterranean and two salt lagoons. The Laguna de Torrevieja covers about 1,400 hectares and the Laguna de La Mata about 700, and together with the strip between them they make up a natural park of some 3,700 hectares. The larger lagoon is the pink one, coloured by halobacteria and the alga Dunaliella salina, and its salt concentration is higher than the Dead Sea: past about 300 grams per litre the salt crystallises and falls to the bottom. The salt works here produce in the order of 600,000 tonnes a year and are the most productive in Europe.

What that means for a door is simple. On a windy day the air carries salt off the sea on one side and off an evaporating hypersaline lagoon on the other, and a typical Torrevieja home has its front door somewhere in between. Rainfall averages around 260 millimetres a year, so very little of it gets washed off again.

What the salt actually does to the pins

A euro cylinder is a row of small spring-loaded pins in narrow brass chambers, with tolerances measured in tenths of a millimetre. It relies on those pins dropping freely.

Salt arrives as an aerosol, settles, and draws moisture out of the air. In the chambers it becomes a fine abrasive paste. Three things follow, in order:

1. The key starts to feel gritty. Still works, but you notice it.
2. It needs a particular angle. You find yourself lifting the key slightly, or pulling the door towards you. That is the stage most people live with for a year.
3. It stops. Usually with the door locked, usually at an inconvenient hour, and usually with the key snapping off because somebody applied force to the last stage of something that had been warning them for months.

Metal parts corrode too, which is why exposed gate cylinders and terrace door mechanisms here have such short lives compared with the same product in a stairwell a hundred metres inland.

Why oil makes it worse

The instinct, when a key goes gritty, is to spray oil into the keyway. It is the single most common thing people do to a lock in this town, and it is close to the worst.

Oil is sticky. It catches the salt and dust instead of flushing them away, and the paste it forms sets harder than what was there before. A lock that was merely gritty becomes a lock that is gummed. Locksmiths here open lock after lock whose pins are set in a grey-brown grease that was never meant to be inside it.

If a lock needs lubricating, it needs a dry lubricant made for locks — a PTFE or graphite-based product — and very little of it. If it needs more than that, it needs cleaning, and if cleaning does not fix it, it is worn out.

Which locks suffer most here

In rough order of how hard a life they lead:

• Garden and pool gate cylinders. Fully exposed, often cheap to begin with.
• Terrace and solarium door mechanisms. Salt plus sand plus thermal movement.
• Front doors of ground-floor units facing a street or garden, particularly near the seafront and on the lagoon side of town.
• Front doors on a shaded communal landing. By far the longest-lived, because they see almost none of this.

That is also roughly the order in which it is worth spending money on better-quality cylinders: on an exposed gate the difference between a cheap cylinder and a decent one can be several years.

When it is finished

A cylinder that has ground its own pins can be cleaned and will feel better for a few weeks, but the wear is permanent and it will fail again. There is no honest way to repair it.

The test is simple. If the key still turns smoothly once the lock has been cleaned and correctly lubricated, it has life left. If it turns smoothly only when you hold your mouth right, replace it and choose the moment yourself, rather than letting the lock choose it for you at eleven o’clock on a Sunday night.