< BURIED & COVERED PATINATION
PATINA FINISHING AND PROTECTION
Once a patina has fully developed on a cast metal surface, it is considered good practice to allow the finished work to stand for a period of some days before adding any protective wax coating. Standing permits the patina to stabilise and settle. Unlike many other metal surface finishes, a patina often remains active to some extent after it’s initial application to the cast, continuing to developing further, usually in a way that makes it near impossible to successfully reproduce an aged patina artificially. For this reason the restoration of an antique patina should be supervised by a qualified conservationist. Consultations with an expert should prevent any irreparable damage or devaluation to the artwork.
Under most circumstances a simple, clear and unscented polishing wax of a type available in high street shops, is suitable for protection of a patina; though occasionally JADE OIL and other preparations can offer a more than acceptable alternative. BEESWAX, is often chosen for use as a quality finishing wax and is considered more durable than most proprietory blends – though being a hard wax some prior softening of beeswax with a suitable solvent (such as fine turpentine), may be necessary.
Restoration technicians and conservators frequently use good quality microcrystalline waxes to apply a protective coating to sculpture. The exceptionally hard and durable CARNAUBA vegetable wax is also well suited for the finishing of any work intended for display in an exposed or exterior location. The application of a protective wax to patinated metal is usually done with the aid of a soft cloth or brush and a light, gentle buffing action. Once dried and hardened, the wax finish can be lightly polished with a clean soft cloth.
In all cases, considerable care is taken not to damage the underlying patina when the protective coating is applied. Some patina deposits are more prone to disturbance than others (especially those that precipitate a heavy oxide layer). A fragile patina may have a liquid wax protection applied via a spray diffuser, or otherwise undergo no protective treatment whatsoever (a possibility if the finished work is to be situated in a stable [indoors] environment and is unlikely to be handled). Before polishing a delicate waxed patina with a soft lint free cloth, it is advisable first to dust the cast with a fine coating of unscented TALC. The talc helps FIX the wax and acts as a dry lubricant, preventing the patina deposit from being abraded or ‘lifted off’ the cast’s surface. Talc should not be used if a slight lightning of the surface is undesirable.
Many patina deposits show a notable change of tone (or even colour), when a protective wax treatment is applied. If a wax treatment is applied to a warm or hot cast for instance, the patina will often darken down somewhat – this change is usually permanent and the effect should be allowed for when deciding at what point the patina application is arrested. If a wax coating is applied to a fully cooled off and settled patina, any change in the appearance of the patina is usually only temporary and the original tonal values and colour will normally recover as the wax’s solvent component air dries.
ENHANCED WAX FINISHES > |
