An Improved Method of Soldering Aluminium Joints.
Year: 1898

page_text: Date of Application, 14th Feb., 1898-Accepted, 11th Feb., 1899
COMPLETE SPECIFICATION.
An Improved Method of Soldering Aluminium Joints.
I, HERBERT WILLIAM STILWELL, of 109A, Gosford Street, in the City of
Coventry, and County of Warwick, Electro Plater, do hereby declare the nature
of this invention and in what manner the same is to be performed, to be particu-
larly described and ascertained in and by the following statement:-
The invention has for its object a simple method of connecting or soldering
together various parts made of aluminium.
I first by means of fine emery cloth and clean rag or the like, clean off all
grease and dirt from those parts of the articles to be soldered and I then immerse
the said parts in a solution of black ash, American potash or pearl ash, or other
suitable alkali until the greasy nature of the metal is destroyed and the surface
left dull or removed, about 4 lbs. of alkali to 1 gallon of water being found to
answer well. This solution is preferably boiling. The articles, or those parts
which are to receive the solder, are then plunged for a few minutes into a solution
composed of equal parts of nitric acid, sulphuric acid, muriatic acid and water to
destroy or remove the black ash or the like and thereby allow the nickel or other
metal to adhere to the aluminium.
After the articles are thus prepared I place them in an electrolytic bath and
deposit a coating of nickel or other suitable metal on the parts so prepared.
The bath contains a larger quantity of the salts of nickel or other metal than
is usual when depositing nickel electrolytically, and I employ a stronger electric
current than usual, the strength being sufficient to "burn" or turn the metal
black and ensure the nickel or other suitable metal passing into the pores of the
aluminium or becoming securely attached thereto, the electrolytic bath being of
strength of about ten degrees by Canning's nickelometer and the electric current
being about seven volts. The parts are then tinned, preferably with a mixture
of molten lead and mercury, by applying a gentle heat; other tinning alloys may
however be used.
The parts to be connected or soldered together are placed in contact and soldered
in the usual manner.
The heat employed in last part of the process causes the mercury to evaporate
and leaves the solder intimately mixed with the lead in the pores of the aluminium.
Sheets of aluminium may thus be coated with tinuing or soldering metal on one
surface and then be used for making cheap jewellery, in which the parts are
soldered together.
Having now particularly described and ascertained the nature of my said in-
vention and in what manner the same is to be performed I declare that what I
claim is:-
-
1. The improved process of connecting or soldering articles made of aluminium
consisting in cleaning the parts, immersing them in a solution of black ash or other
suitable alkali, plunging them into a strong acid solution, plating with nickel or
other suitable metal in a strong bath and with a more powerful current of electricity

page_text: than usual, tinning or coating the surfaces with a suitable alloy and soldering
the parts together substantially as herein described.
2. The improved process of connecting articles made of aluminium consisting in
applying a coating of nickel or other suitable metal in a strong bath by means
of a more powerful electric current than usual, tinning or coating the parts with
an alloy of lead and mercury or other suitable alloy and connecting them by means
of solder, substantially as herein described.
1000
HARRIS & MILLS,
23, Southampton Buildings, London, W.C.,
Agents.
HARRIS & MILLS,
23, Southampton Buildings, London, W.C.,
Agents.