Day 33: Smelting
TV6, the last programme in the series, most of the tools are broken or
missing. Our resources are very low, so old projects are cannibalised
for wood, screws, nuts and bolts. Everything we make is designed around
the materials available.
The weather is great,
just like a British summer day, even so, when we try to light some coal
it is too wet to get it going. We are running out of time. Kate and some
of the crew help me to spread a tarpaulin on the floor and spread the
coal out in the sun to dry. Getting a furnace going isn't as easy
as just lighting a fire. The whole of the inside needs to heat up, and
that takes time.
I make a thermometer
out of a brick and some small pieces of metal. It is based on the principle
that different metals melt at different temperatures. Lead melts at about
330oC, aluminium at 660oC, brass at 1027oC,
gold at 1062oC and copper at 1083oC. If the copper
in my ‘thermometer' melts then the gold in the crucible should
also have melted. The other metals indicate how close we are to the temperature
that we want. However we have two problems. Firstly the metals that I
use are likely to be alloys (mixtures of metals) so the melting temperatures
will be different. Secondly we were unable to get the ‘thermometer'
into the middle of the furnace. Even so, it will give an indication of
the temperatures inside the furnace.
we get some coal to burn in an open fire and drop it into the furnace.
On top of the hot coals we mount a grill on which we place the crucible
of gold. We then take it in turns to pump the bellows to get the fire
burning nice and hot. I didn't expect them to last long, but with
the exception of a couple of broken broomstick handles they are OK for
the whole day. The only other problem was when a hot piece of coal was
sucked into Kate's bellows setting the leather on fire when the
reed valve became stuck. This problem is solved by pouring water on the
pipe leading from the bellows to the furnace, which cools anything sucked
into the bellows before it can reach the leather. After a while we check
my ‘thermometer' the results are inconclusive, so J came up
with the idea of poking a copper olive (used by plumbers) right down into
the furnace next to the gold. Two minutes after putting the olive into
the furnace it has melted, leaving only the steel wire to which it had
been tied. We now know that we are up to temperature so keep the furnace
going until the fuel runs out. As late afternoon develops into dusk the
flames shooting out of the furnace chimney look stunning against the snow
capped mountains. We know that we were in business.
There is no point
burning ourselves trying to retrieve the gold this evening so we leave
the furnace to cool naturally.
Back at the huts we
were to share our last meal with Ricky. He made a local speciality –
whitebait. Here on the west coast whitebait is nearly as valuable as gold.
People will fight to the death to defend their own fishing areas because
the catch can be so lucrative. We ask what Franz Josef has made of us.
Ricky replies, "Better people". I think that he is right.