We recently were asked to make some blister steel from wrought iron
to discover whether the process could have been undertaken at a
medieval ironworks that was being studied.

For the purposes of this task we used very early puddled wrought
iron, although charcoal wrought iron would have been used at the
time. The wrought iron was surrounded in charcoal and placed in a
clay box which was then heated in a furnace for 12 hours at 900-1000
degreee centigrade.

The results showed indeed that steel could have been made with the
technology available at the ironworks.

However, in subsequently looking at the photographs (which are posted
on http://uk.groups.yahoo.com/group/realwroughtiron/ ), it can
clearly be seen that steel penetration has been made into the iron,
leaving a wrought iron core. It occurred to us that given that the
technology was available, that it may have been used for weaponary,
tools etc. For example a large number of arrowheads could be stood
upright in sand in a clay box to the level where a steel tip was
required, the exposed tip then being surrounded in charcoal and
heated in the furnace. Similarly, a sword or axe could be heated for
a predetermined time to ensure sufficient penetration to have a steel
edge but retaining a softer wrought iron core.

Technically, from a blacksmith point of view there seems little
technical advantage to fireweld a steel edge on the wrought iron to
make such items and a considerable advantage in time by using this
method. If you estimate that to fireweld steel into an arrowhead
would take approximately ten minutes and Robert Hardy estimates that
one million arrows were used at the battle of Cressy, the time saving
would be over 3,000 man weeks (at a 50hr week). As this approach
struck us almost immediately when looking at the treated bars and we
were not even considering the subject it would seem to us that smiths
at the time would have reached a similar conclusion.

As we are neither weapons experts or armourers we do not have
sufficient knowledge or experience in this field to know whether this
is a method that was actually used but we thought it interesting
enough for those that are to consider this as a possibility.

Steve Suff
Chris Topp & Co