A fine lighter is one of the few luxury objects that is also a small machine. It has a fuel reservoir, a valve, a mechanism that must produce a spark or a flame on demand, and a finish that is expected to look the same after twenty years in a pocket as it did on the day it was unboxed. Set against a watch or a fountain pen it asks for remarkably little. But the little it asks for is specific, and most of the troubles collectors bring to us trace back to the same three things: fuel, flint and finish.
What follows is general good practice for any S.T. Dupont lighter. It is not a refilling manual, because the maison publishes instructions for each model and those should be followed to the letter. It is, rather, the set of habits that keep a lighter ready to work and pleasant to look at, whether it is carried every day or brought out a few times a year.
Fuel: keep it fed
The single most common cause of a disappointing lighter is not a fault at all. It is a piece that has been allowed to run dry and then sit. A lighter with a little gas in it is a sealed, stable system; a lighter with none is one in which the seals have nothing to hold and the valve nothing to do. Neither state does immediate harm, but the second is where small problems begin.
Use a quality butane, and ideally the gas the maison recommends for your model. Cheaper fuels carry more impurities and, over time, those impurities are what block jets and gum valves. Keep the piece topped up rather than waiting for it to fail; the moment to add gas is when the flame begins to shorten, not when it disappears. Refill in a cool room, away from any open flame, and follow the model's own instructions for how, and how much.
Long spells unused
Many collectors own more lighters than they use, and a piece that lives in a drawer between occasions has its own needs. The worst course is to store it bone dry for months. Better is a partial fill and an occasional relight, once a month or so, which keeps the valve moving and the seals in contact with gas rather than with air. Think of it as the equivalent of winding a watch that is not being worn.
If a lighter has been neglected for a long time, do not force anything. Bring it back gently: a modest fill, a wait, a few careful attempts. If it does not respond, the sensible course is service rather than experiment. A well-made lighter is built to be maintained, and a mechanism that has stiffened through disuse is usually a straightforward matter for a technician and a frustrating one for an owner with a screwdriver.
Flint, where there is one
Not every model relies on a flint, but on those that do the flint is a consumable, and it is the part most likely to run out at an inconvenient moment. A flint wears down gradually and then fails abruptly. The warning signs are a spark that grows weak or a wheel that needs several strikes where it once needed one.
The remedy is trivial: keep a spare or two, ideally the maison's own, in the box the lighter came in. Fitting one is a matter of moments on most designs and is set out in the model's instructions. There is no economy in stretching a flint past its useful life; a worn flint makes the mechanism work harder than it should and can leave a fine grey residue where the spark once was.
Heat, sun and where a lighter lives
Butane expands when it is warm. A lighter left on a dashboard, on a sunny windowsill or beside a radiator is under more internal pressure than its designers intended, and the fuel inside it may behave unpredictably when it is next used. Heat is also unkind to the finish: lacquer, plating and any leather sleeve all age faster in warmth and direct light. A drawer in a room at ordinary temperature is the right home. A glove box in a Canadian July is not.
Cold is less dangerous but not irrelevant. A lighter brought in from a winter coat may light poorly until it has warmed in the hand for a minute. That is the gas, not a fault, and patience is the only remedy required.
Store the piece upright where possible, the way it would sit on a table. It is the orientation the mechanism was designed around, and it keeps any stray oils or residue away from the parts that matter.
Protecting the finish
The mechanism can be serviced; the finish, in most cases, cannot be restored to new. That is the argument for treating the outside of the lighter with slightly more care than the inside. The enemies are grit and hard contact. A lighter that shares a pocket with keys or coins will pick up fine scratches within weeks, and while a brushed metal surface hides them, lacquer and polished plating do not.
A soft pouch or a lined drawer is enough. The original presentation box does the job perfectly well and has the advantage of keeping the spare flints and instructions in the same place. Between uses, a wipe with a soft, dry cloth removes fingerprints and the light oils of handling. Nothing abrasive should ever touch a Dupont; no polishing compound, no household cleaner, no solvent. If a mark will not come away with a soft cloth, it is better left than attacked.
Travel and the pocket
A lighter that travels needs the same protection in motion that it gets at rest. A dedicated pocket, a small case or the pouch it came with keeps it from rubbing against anything harder than itself. Before flying, check the current rules for carrying a lighter; they vary by country and by airline, and the regulations, rather than habit, should decide whether the piece goes in a pocket or stays at home.
On a night out, the small courtesies matter more than they seem. Set the lighter down on a napkin or a leather coaster rather than directly on stone or glass, and keep it clear of spilled drinks. Alcohol and sugar are both unkind to a finish left to dry with them on it.
A light hand with the mechanism
Everything on a well-made lighter moves with a definite, deliberate feel, and it should never be forced past that feel. Do not over-tighten a filler valve or a flame adjuster; snug is enough, and beyond snug is damage. Do not flick a cap open and shut for the pleasure of the sound more than the occasion calls for, since every cycle is wear, however slight. Close the cap fully after each use so the mechanism is protected and the gas is not drawn down needlessly.
If something does begin to feel wrong, a stiff hinge, a flame that will not hold, a valve that hisses, stop using the lighter and have it looked at. The maison's lighters are designed to be serviced across a lifetime, and an early repair is always smaller than a late one.
A simple routine
None of this amounts to much in practice. Keep gas in the piece. Relight it now and then if it is not in daily use. Keep a spare flint where you can find it. Store the lighter upright, away from heat and sun, in something soft. Wipe it with a soft cloth and nothing else. Never force a part that resists.
Owners who do those few things tend to find that their lighters simply work, year after year, and that the only maintenance they ever pay for is an occasional service. As an authorized S.T. Dupont reseller, El Laguito Cigars can advise on the correct gas and spares for any model we carry, and on where to send a piece that needs a technician's attention.