More on Wrought Iron:
This metal is created using special equipment and processes that result both
a distinctive physical structure and also a specific chemistry. All three of
these factors combine to a metal that is quite different than modern steel alloys.
'Wrought' in this case refers to the hammering process required to compress
and purify the spongy iron bloom that is extracted from a bloomery furnace.
There will always be some microscopic layers of silica slag remaining within
any wrought iron bar. It is this slag that gives this metal its distinctive
fracturing pattern, breaking as short tendrils. "Iron' is the primary element
in the metal, and unlike modern alloys, most wrought iron will have few other
components. Typically wrought iron has extremely low carbon content, on a grinder
the sparks will test as dull red balls.
Wrought iron is an ideal material for the process of hand forging. It will remain
workable over a wider range of temperatures than modern steels. It will tend
to de-laminate as it is worked, requiring it to be re-welded to consolidate
the surface (a step not required with steel). Any forge welding is considerably
easier with wrought iron, where the slag incorporated within the material tends
to float to the surface at welding temperatures, so that often no additional
flux needs to be applied.
The modern steel alloys start replacing wrought iron when the Bessemer furnace
was introduced about 1855. This new technology not only allowed for greater
control in the iron smelting process, it also increased the volume of production
by an order of magnitude. Both of these factors made the new steel more dependable
in quality and also considerably cheaper than the old wrought iron. By the early
1900's very little of the older metal was still being produced.
The last commercial production of true wrought iron was stopped in 1974. There
has been no new wrought iron produced in commercial amounts * anywhere in the
West since that date.
Any real wrought iron available for sale today will be reclaimed
from structures being dismantled. Most commonly the material will be from structural
elements from things like bridges. In some cases, larger diameter bars may be
reworked down before being sold. A modern industrial 'substitute' is sold, under
the trade names 'Electric Iron', 'Rivet Iron' or 'French Iron'. These materials
are in fact low carbon content bessemer steels, with a carbon
content in the range of .05%. They have the crystal structure of modern steel,
without the linear texture (from slag inclusions) of wrought iron. Even
when available in suitable sizes, those modern materials run roughly three to
four times the cost of standard mild steel bars.
Typically, only small amounts in random dimensions of true wrought iron, often
originally created in the 1850's, can be found. Often this collected by blacksmiths
as personal stockpiles of these historic materials. Historic wrought iron is
treasured for its easy working when hand forged and its better aging characteristics
than modern steels. It also becomes an interesting addition to the mix when
creating layered steels for knife making.
The term 'Wrought Iron' has undergone a radical shift in its meaning at the
hands of popular culture.:
• The term moved from the technical language of the blacksmith into a
descriptive term used by antique collectors in the early 1900's. When referring
to objects hand forged by blacksmiths in the Settlement / Colonial period, they
were correctly described as being made of wrought iron.
• Eventually however, the definition became less exact, coming to be used
for 'any object that had been hand forged' - regardless of the metal content.
• Over time (into the 1950's, as blacksmiths disappeared) the term 'wrought
iron' has come to refer to 'any piece of metal with a shape that is painted
black'. In this the 'wrought' was separated from the 'iron'. 'Wrought' was used
in its much less specific definition of 'shapped'.
• Now objects that are composed of modern mild steel, formed cold, shaped
by machine (even cast or plasma cut!), and then painted black - are referred
to as 'wrought iron'.
Amazingly, the term 'Wrought Iron' is now become mere advertising copy.
Retailers will describe objects which just vaguely have the 'look' of shaped
metalwork as 'wrought iron work'. Take a look at any recent Home Depot flier,
and you will see ALUMINUM railing pieces, which have been mould CAST - described
as "wrought iron railings"!
This is almost as far from the correct meaning of wrought iron as its
possible to get.
( * There are two exceptions:
ï There are a small number of museums preserving the history of technology and
industry. Some of these will conduct smaller scale demonstration firings of
their historic blommery furnaces. The metal produced is typically kept inside
the museum community for restoration work.
ï The second exception are the small group of people using experimental archaeology
methods to rediscover what are often ancient and lost smelting techniques. Yields
from these test smelters are quite small, typically 5 - 10 kg per firing.)
Wrought Iron at the Wareham Forge
As an Artistan Blacksmith, Darrell Markewitz uses the heat of the forge, the skill of his hands and the power of the hammer to forge individual bars into unique shapes. | |
The Wareham Forge blends historic, traditional, and modern working methods and tools. Darrell's extensive background in Viking Age objects and skills makes his approach and style unique. | |
As a one man workshop, the raw force required to shape heavy bars is provided by a 50 pound air powered hammer. | |
The primary material utilized is modern mild steels or specific alloys. Forging industrial structural materials (pipe / angle / channel) is a specialty. | |
A stockpile of antique wrought iron has been gathered over the years. This material is primarily reserved for detailed museum reproductions or incorporated into layered steel billets for bladesmithing. | |
Darrell is a leader in the 'Early Iron' movement, the most experienced in Canada. He regularly operates bloomery iron smelting furnaces to create actual wrought iron using historic methods. |