Brazing and soldering are similar processes, both joining
two (or possibly more) metal items together using a filler metal that has been
melted. The filler metal needs to have a lower melting point than the metals
being joined and to make sure that it holds properly it needs to be clean and
free of oxides. However it should be noted that not every metal will stick to
all metals. In brazing, the filler metal’s melting point should be above 450⁰C,
and in soldering, the melting point needs to be below 450⁰C.
Early examples of brazing and soldering are from around 2500
BCE. Pieces of pure gold were joined with gold and silver alloys of a lower
melting point to make jewellery and other trinkets. Primitive furnaces were used
to melt the metals. Due to the fact that they have been in use for thousands of
years, it is not clear when brazing, soldering and other types of metalworking came to
the UK.
Could we recreate early brazing and soldering in the woods?
It would not be sensible. The melting point of pure gold is 1063⁰C and this high
temperature would be difficult to achieve in a furnace in the forest floor, and
would be a fire hazard as the surrounding earth would also become extremely
hot. To
recreate early brazing we would have to provide ourselves the pure gold and the
gold and silver alloys used as filler metals as these will not be naturally
found in the woods.
(Zoe - 5th February 2012)
We have some gold in our chemistry store!
ReplyDeleteWhat is solder made of? If it really does melt below 450 degrees C then we could greate that temperature, surely? I realise we would need to rely on the raw material of solder being brought to us from elsewhere