Well-made domestic metalwork, such as door handles and light fittings, have obvious functional and visual appeal, but how many of us understand the technique of lost-wax casting? Certainly used by the Incas and, possibly, by the ancient Egyptians, lost-wax casting is particularly effective for making and replicating finely detailed metal objects. It is a complex process that generally requires several skills and stages, involving the creation of two moulds for each different design.

Barrett & Jarvis, specialists in non-ferrous lost wax casting, produce a huge variety of metal objects ranging from artworks to functional fittings for a clientele that includes Brit artists the Chapman brothers, Aspreys and the owners of country houses in Britain, Ireland and the US. Uniquely, the firm combines design, modelmaking and casting, its success being partly due to the complementary artistic skills of the partners, Rodger Jarvis and Garry Barrett. They met at Medway College of Art 40 years ago and set up in partnership in 1975. Mr Jarvis studied crafts such as furniture making and silversmithing before becoming a mould maker; Mr Barrett, a gemologist and jewellery maker, learnt the art of metal pouring when making watches for the Arab market. Most of the work is done by them, although they do employ assistants when required, such as a specialist polisher.

‘We can do anything you want in bronze, brass, gold or silver,’ says Mr Jarvis. The difference between bronze and brass ‘is mostly down to colour: brass is brassier, but, when untreated, acquires a dark coppery tone. Bronze weathers well, so it’s better for outdoor pieces; people think it’s more expensive, but it’s not. Both require the same process and can be finished to appear naturally aged (using a flame run over the surface), or polished, and occasionally gilded.’

Barrett & Jarvis made the Shergar cup and the replica of the Tudor sword hilt found in the Mary Rose, as well as numerous sculptures, trophies and other decorative objects. But most of their work is functional fittings for buildings and furniture replicating Pugin’s grilles at the Palace of Westminster and Mackintosh’s lighting designs at 78, Derngate, Northampton; restoring an antique brass chandelier crudely adapted for electricity; designing new fittings for a house in Tite Street. Many commissions involve replicating existing pieces, but some require an original to be made in the studio first usually hand-modelled in wax or carved in wood with carefully prepared artwork based on detailed research.

The first mould is made by encasing the piece in rubber (formerly gelatine was used). Wax pellets are then melted down in a wax-injector machine, and a pressure pump is used to squeeze the molten wax into the rubber mould. It takes only a few minutes to set, after which the wax model is ready for the ‘investment’ stage. This involves fitting it to a rubber base and placing it inside a perforated metal drum, into which plaster is poured, hardening quickly into a solid block, or ‘flask’. The base is then removed, the wax is steamed out of the cavity and the flask is put into a kiln to dry out.

The next day, an ingot of raw metal is melted in the furnace and the molten substance is poured into the plaster cavities as the flask sits in a vacuum tank. It is left to cool for a few hours and then quenched in water, when the plaster melts off to reveal the object cast in metal.

Barrett & Jarvis 01850 893500; www.barrettandjarvis.com