Day 32: Smelting
a lot more mobile than I did at the end of the last challenge. Even with
rest, it's going to take 5 or 6 weeks for my ribs to mend, and I
plan to take things easy in this final programme.
My final challenge
is to purify all the gold that we've amassed - ‘amassed'
seems a rather grand word for the 6g that we've managed to extract
over the last 5 weeks. Kate tells me that I'm in charge of building
a furnace to smelt the gold. Once we've done that, Jonathan, Ellen
and Kathy have the job of designing and making something from the pure
gold that we manage to recover.
We all set about designing a furnace that we hope will give us the 1200
or so degees Celsius that are needed to melt the gold. In the kit for
this challenge, we've been given a pile of firebricks, which will
help enormously. We decide that we need to insulate the firebricks with
clay mixed with charcoal, so that as much of the heat that's generated
by the burning coals will stay inside the furnace and not be lost to the
outside world. There are enough firebricks to build a double-walled furnace,
but we won't be able to build the outer wall until the inner wall
of firebrick (lined with clay/charcoal) has dried out. We set about constructing
the inner furnace, with Kathy and Ellen doing a great job of churning
out loads of clay/charcoal ‘pizzas'.
really is a team effort, with Mikey L making a wonderful pair of leather
and plywood bellows, and Jonathan and Mike working on a way of ‘measuring'
the temperature inside the oven. By the end of the day, we have a lined,
inner furnace, which we charge with hot coals and leave gently simmering
overnight to dry out. This is a process that usually takes two to three
weeks to do properly, so we're all feeling a little apprehensive
as we leave the sawmill at the end of Day 1 with our little furnace glowing
away in the rear-view mirror. What will greet us tomorrow morning? Perhaps
drying the clay/charcoal liner so quickly will prove to be too much, and
all we'll succeed in doing is cracking the clay, which won't
help at all. There are already strong doubts as to whether the furnace
can generate the temperatures we need, even if all goes well tonight.
We shall just have to wait and see.