Improvements in the Art of Soldering Aluminum.
Year: 1891

page_text: Date of Application, 26th May, 1891-Accepted, 18th July, 1891
COMPLETE SPECIFICATION.
Improvements in the Art of Soldering Aluminum.
We, FRANK JOHN PAGE, Tool-maker,. residing at No. 6 Henry Street,
Waterbury, County of New Haven and State of Connecticut and HARRY ALBERT
ANDERSON, Machinist, residing at Platt Block, Waterbury, County of New
Haven and State of Connecticut, one of the United States of America, do hereby
declare the nature of our invention and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:-
This invention relates to certain novel and useful improvements in joining
pieces of aluminum, but more particularly does it appertain to a flux for use either
with ordinary solder or with specially prepared inetallic soldering compositions,
either in joining pieces of aluminum to like pieces, or in joining pieces of aluminum
to other inetals.
Owing to the difficulty which amounts almost to an impossibility, of forming a
satisfactory solder joint between two pieces of aluminum, it is now customary to
utilize between the parts to be fastened together, a binding strip of brass or other
metal, which is capable by present methods, of being more or less successfully
soldered to the aluminum; but if a strong and perfectly tight joint is desired, it is
necessary to resort to rivets or other mechanical fastenings.
Our invention, in view of the foregoing, consists in the use in soldering of the
chloride of silver as a flux either alone or combined with other substances.
Perfectly tight joints may be made between adjacent surfaces of aluminum, either
lapped or butted, by the use of ordinary solder in connection with this flux, and
also between dissimilar metals of which aluminum is one.
We produce the chloride of silver by any usual chemical process, but the
following is operative.
Into a vessel containing nitric acid which is preferably heated in a water bath,
we dissolve metallic silver to the point of saturation. Into this saturated solution
we introduce salt or other substance containing chlorine, in quantity sufficient to
precipitate the chloride of silver. We then decant the liquid, fuse the precipitate
so far as to bring it to a solid mass, and then comminute it; or we may obtain the
chloride by the treatment with chlorine of the commercial nitrate of silver.
In joining together two pieces of metal, one or both of which are aluminum, we
first place them in such relative position as is desired in the joint. Then along the
line of desired junction we thinly spread the flux above described. Then by means
of a blow-pipe or other suitable device, we introduce upon the surfaces of the parts
to be joined melted solder which, as soon as it strikes the line of flux, follows it
rapidly to the end, running most freely, and then setting into a hard, perfectly solid
joint which will neither crack, flake nor check.
We contemplate using the chloride of silver either in comminuted or other
form, the gist of our invention resting in the broad idea of using the chloride of
silver as a flux in soldering aluminum, and whether alone or combined with other
substances.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :-
The method of soldering aluminum which consists of fluxing the surfaces to be

page_text: joined with the chloride of silver, and then introducing solder upon said surfaces,
substantially as described.
Dated this 25th day of May 1891
H. B. BARLOW,
Agent for Applicants.