A common task encountered by the Gentleman's Gentleman is polishing brass1. In times gone by, this was a task that would be carried out by junior members of the household staff. Establishments of refinement in the 21st Century simply send brass items to specialist metal polishers for refurbishment. Moreover, brass no longer lends a household an air of sophistication and is more commonly found in the dwelling-places of the working classes, and orchestras.
Brass is an alloy of copper and zinc, and when exposed to air, it rapidly oxidises. This tarnish actually forms an airtight seal which prevents further oxidation, thus brass items around the home will almost certainly have a layer of lacquer applied during manufacture to seal the metal away from air. Over time, and with use, this lacquer can be worn away and the brass will begin to tarnish. The best way to restore brass to its full glory is to strip back the lacquer entirely, remove the tarnish, polish and then seal with a fresh coat of lacquer.
To begin polishing your brass, clean the item thoroughly in warm soapy water, then dry with a soft cloth. It may well be that the brass is not tarnished at all, but the lacquer has become dirty. Look for worn ridges of lacquer. If the lacquer has in fact been worn away, it will be necessary to remove all that remains.
Removing the Lacquer
To remove lacquer use acetone, more commonly known as nail polish remover. Wearing rubber gloves, gently wipe the acetone onto the brass using a cotton wool ball. A gentle rubbing action will remove the lacquer. For awkward shapes, use an old toothbrush. Be sure to first obtain permission from the owner of the toothbrush, and return the toothbrush to the cleaning box and not the bathroom.
An alternative to acetone is ammonia. Be careful to work with ammonia in a well-ventilated space as the vapours can be quite eye-watering. You can also use vinegar mixed with equal parts of water, cigarette ash on a halved lemon, ketchup, cola or a mix of toothpaste and Worcestershire sauce. Whichever method used, be sure to wash in warm soapy water afterwards to remove any traces of the cleaner (both item and person).
One way or another, the lacquer is removed and we must now tackle the oxidised or tarnished areas of brass.
The best way to tackle tarnish is with a proprietary brass-cleaning product such as Brasso. This contains solvents which can dissolve small amounts of residual lacquer, abrasives to remove the atoms-thick layer of oxidisation, and oils to help seal the brass from the air. The most common mistake made is to use too much brass cleaner. The black residue seen on many cloths is a sign of overuse of cleaner. Using a soft cloth and a mere smidgeon of cleaner, start to rub the tarnished areas quite firmly in the direction of the grain in the brass; much as one would oil a polo stick, croquet mallet or the flanks of a fine charger.
Try to generate heat as this helps to break the atomic bonds in the oxide. Heavily tarnished pieces can be cleaned with extra fine wire wool, but do take care to only rub in the direction of the grain and not in circles, as this will create scores which are most tiresome to polish out. As the cleaner dries, move on to another area until the entire surface is covered in a fine chalky film. Taking a second polishing cloth or wadded-up newspaper (one finds the Times always achieves a superior shine), begin to buff the surface to a high shine. Once the brass is gleaming, it is time to seal the shine beneath a lacquer.
Lacquer is best sprayed on, and spray cans are readily available in reputable commercial establishments. A good alternative is a polyurethane spray which will last longer than lacquer. Again, use in a well-ventilated area - the stables or carriage houses are ideal. Spray the piece very lightly and evenly according to the directions on the can (try to recreate the glow seen on a hound's nose after an energetic chase). It is better to have multiple thin coats than one thick coat as this will avoid unsightly drips.
Once the lacquer is dry, very lightly polish again using a fine olive oil or natural mineral baby oil. Although this will smudge easily and attract dust, necessitating repeated cleaning and re-application, it really does give brass that extra 'zing' only usually found on pieces in high class abodes.