IMPROVEMENTS FOR WELDING COPPER
Year: 1874

page_text: PROVISIONAL SPECIFICATION left by Martin Benson at the Office
of the Commissioners of Patents, with his Petition, on the 7th
February 1874.-A communication from abroad by William G.
Rehbein, Henry Roberts, and Perry Espey Brocchus, all of the City
and County of Baltimore, in the State of Maryland, United States
of North America.
I, MARTIN BENSON, of No. 9, Southampton Buildings, London, do
hereby declare the nature of the said Invention for "IMPROVEMENTS FOR
WELDING COPPER," a communication to me from abroad by William G.
Rehbein, Henry Roberts, and Perry Espcy Brocchus, all of the City and
County of Baltimore, in the State of Maryland, United States of North
America, to be as follows:-
Many experiments have been made with a view to weld copper similar
to the ordinary process of welding iron, but have failed to produce any
practical results for the reason heated copper when exposed to the
atmosphere absorbs oxygen very rapidly and causes it to waste, a process
commonly known as scaling, and the copper thus oxidized will not weld
or unite, and if the copper is heated sufficient to resist the effect of the
oxygen it melts or fuses and becomes of course unfit for welding.
copper could be welded in a vacuo to exclude it from the oxygen in a
If

page_text: heated state these difficulties would be overcome, but no practical means
have yet been discovered for thus welding it.
My improvement consists in a process for welding copper by which
there is as perfect and as strong a union made between the welded
surfaces or parts as in any other portion of the bar or sheet of copper of
equal area, and without material loss or injury to the copper in the pro-
cess of heating for welding purposes.
The following is a description of the improved process :-First, take the
biborate of soda (borax) and heat it untill all its water of crystallization is
cvaporated; then pulverize the dry residuum; next prepare the two pieces
of copper to be welded so that the surfaces form a lap joint or any
other desired form of union, then apply the prepared borax on and
between the surfaces and hammer them together when hot. The joint
thus prepared is brought to a white heat powdered over quickly with
chloride of magnesium, chloride of sodium (salt), or with any of the
chlorides or equivalent compounds which may be deemed most suitable
for the purpose of excluding the oxygen, and finally welded. The weld
or joint thus effected will be found to be strong, perfect, and durable.
Another method by which this weld can be effected is by directing a
stream of chlorine gas upon the heated copper during the process of
welding.
The action upon the copper of the chlorine either pure or evolved
from the various salts containing it is readily explained. Being heavier
than the atmospheric air it remains upon or around the heated copper,
thus effectually excluding all oxygen while as is well known it greatly
increases the heat of the copper immersed within it.
This process is applicable to all purposes in the art where it is required
to weld copper together, and will be found more economical for instance
in joining or welding the sheets of boiler and still shells together which
are usaly riveted, also for chains requiring great strength for mooring a
harbour buoys, and on board of vessels where they are alternately
exposed to the action of water and air, which would cause iron to oxidize
and soon become unsafe for use compared with the durability of copper
chains made according to this improved process of welding.