Period character guide: Metalwork

Ironwork has always fascinated me. I love its strength and form and the way it works as a counterpoint to architecture and landscape. There is no doubt that our towns, gardens and parkland would be the poorer without the smart regiments of railings, the filigreed balconies, the elegantly rusting estate fencing, the embellished gates and the myriad other ironwork items.

Since its first use in Britain around 650BC, iron has been employed to make everything from cooking pots to horseshoes. As a consequence the sharp ring of the blacksmith’s hammer was once heard in villages across the land.

The 17th century saw a burgeoning of bold and often intricate ironwork in the form of gates and screens. At the forefront of such craftsmanship was Jean Tijou, a gifted Huguenot, who undertook work at Chatsworth House in Derbyshire and also produced gates for William III which survive today at Hampton Court Palace.

The first significant use of cast iron for building work was in 1714 when railings were erected around St Paul’s Cathedral, although Christopher Wren would have preferred wrought iron. With the Industrial Revolution the use of ironwork extended into practically every sphere of construction. The world’s first cast-iron arch bridge was built over the River Severn at Coalbrookdale, Shropshire, in 1779.

By the 1790s mill buildings were being built with cast-iron columns and Robert Stephenson employed wrought-iron beams for the roof of London’s Euston Station in 1837. Early cast items were relatively coarse although, by the end of the Georgian period, techniques improved.

In the mid 19th century Henry Bessemer invented what became known as the Bessemer process whereby molten pig iron could be turned directly into steel by blowing air through it. Although steel corrodes relatively easily and can lack the aesthetic qualities of wrought and cast iron, it had largely supplanted them by the 1890s because of its strength and workability.

Hot metal
The production of genuine wrought iron and the craft of blacksmithing is carried on today at Chris Topp & Co, a 30-year-old firm based in Carlton Husthwaite, North Yorkshire. The team there make the iron by reprocessing old wrought iron. This is heated but not melted and, using a rolling mill, iron bars are produced to the sizes needed for each job. According to Chris Topp, the material’s quality actually improves with reuse.

A medieval-style gate is just one example of the many commissions undertaken by Chris Topp & Co and Chris told me how working with wrought iron involves constantly heating and reheating the metal to 1,200°C.

Once the gate’s design had been created the first section of the gate to be made was the top rail. For this the blacksmith used tongs to hold a section of hot iron under the electrically driven power hammer to ‘fuller-in’ or drive-in a curved indentation using a large round bar of cold steel. Chris explained that many of the tools and templates used to shape and mould the iron are purpose made for a specific job. Next, the body of the bar was ‘drawn’ or beaten to size.

Just as with wood, traditional ironwork is jointed together. To form the joints, a ‘butcher’, a form of blunt chisel, was used in the initial shaping of the tenons. Callipers enabled the blacksmith to check the size of the finished joint and it was ‘dressed’ with a hammer until the dimensions were exactly right. This process was repeated to create the joints at all four corners of the gate.

To complete the design, many decorative pieces had to be worked individually. The scrollwork was set out and then pulled into place using jigs; the chases on the thistles that top the gate were individually cut; and the various pieces that make up the graceful latch were individually crafted. All the elements were then jointed or welded, a process which involves heating the separate sections and beating them together. What struck me was the elegance that results from such a physical process.

Repairs and replacement
Water and air are the enemies of metalwork so regular maintenance is essential and the moving parts, such as the hinges of gates, should be kept well greased to avoid wear and tear.

Always try to repair rather than replace damaged metalwork. Blacksmiths may be able to weld, rivet or ‘stitch’ items together or make replacements. With cast iron, existing sections can be used to create moulds so that damaged or missing pieces can be replaced.

If you decide you want to create new items, it is worth researching the relevant period styles. Steel is regularly used in ‘reproduction’ work but if not done well there may be obvious signs of it having been welded while the sections can be badly proportioned and spindly.

By comparison, wrought-iron work tends to have substance and style. The bars are generally square or rectangular and may be twisted with flattened, scrolled or tapered ends, which, because they are individually worked, are all slightly different.

While cast iron lacks the delicacy of wrought-iron work, it can be more precise and complex. It is sometimes distinguished by a rough surface and the ‘flash lines’ or seams left by the mould.

Sprucing up metalwork
Good preparation is crucial before repainting metalwork so remove loose paint and rust using wire brushes or wire wool. Chemical paint removers can be an effective way of stripping layers of paint that are obscuring surface detail.

When I clean off metalwork I use a rag dipped in white spirit rather than water to avoid rust and then immediately prime or treat it with a chemical rust inhibitor. Conventional paint systems usually need a primer, undercoat and topcoat, although some metal treatment paints are designed to cover in a single coat and can be painted directly over corrosion.

It is worth remembering that in previous centuries railings and other metalwork were often painted dark red, brown, green and blue, rather than black. The use of black only became common after the death of Prince Albert in 1861.

ABOVE (L-R): Victorian cast-iron columns support a balcony on a London house – they are small versions of the soaring examples you can see at 19th-century railway stations; These curvaceous Victorian railings look remarkably modern in style; Balconies became popular in the Regency period; this one, in London, is supported by slender cast-iron columns that gave the structure stability and strength.
BELOW (L-R): The Victorians liked to decorate with ornament, such as leaves, arrows, flowers and urns – often the detail is lost today due to layers of paint.

Word for Word: A wrought iron glossary
CAST IRON An alloy of iron and carbon with items formed in moulds. Relatively corrosion-resistant, it has little tensile strength and is brittle so an impact may cause it to crack or shatter. Although components are not easily worked they can be welded or machined and can be often identified by their identical repetitive patterns.
STEEL A refined form of iron. It can be worked when hot or cold and is often used as an alternative to traditional wrought iron but has poor resistance to corrosion.
WROUGHT IRON The product of smelting iron ore with charcoal. It has a high tensile strength because of its fibrous structure, is relatively corrosion-resistant and can easily be worked while hot.

Creating new pieces from reclaimed wrought-iron

Visit Roger Hunt's website at huntwriter.com

WORDS ROGER HUNT PHOTOGRAPHS ROGER HUNT; CHRIS TOPP
Featured in the June 2010 issue of Period Living