target="_blank" rel="nofollow" href="#ulink_3ae5ee2e-9c29-5ef9-acbb-5329c6ea3406">Flux.
Horizontal or Underhand Joints.
Wiped Joint between Lead and Cast-iron Pipes.
CHAPTER VIII Hard-soldering with Silver Solder
Requisites for Silver-soldering.
The Method of Silver-soldering.
Soldering Small Work with Paillons.
Quenching Silver-soldered Work.
CHAPTER IX Soldering Gold and Silver Jewellery
CHAPTER XI Welding Iron and Steel under the Hammer
Welding of Steel Specially Considered.
CHAPTER XIII Managing Blow-lamps
CHAPTER XV Electric and Thermit Welding Briefly Considered
CHAPTER XVI Oxy-Acetylene Welding
CHAPTER I
The Various Processes of Joining Metals
Apart from the use of rivets, screws, etc., metal is commonly joined by soldering, brazing, or welding, three groups of processes that have one thing in common—the use of heat to fuse either the metals themselves or an alloy which is interposed to consolidate the joint. The word “solder” is derived through the French from a Latin word meaning “solid.”
Soldering may be “soft” or “hard.” Soft-soldering uses lead-tin alloys which are easily melted in a bunsen gas flame or with a hot iron or bit; while hard-soldering employs a silver-copper alloy, to melt which a mouth blowpipe at least is necessary. Brazing is hard-soldering with spelter (brass), and a forge or a heavy blowlamp or a powerful blowpipe must be employed to provide the heat.
Welding is a fusion process which in the past was almost entirely confined to wrought-iron and steel, these metals possessing the property of weldability to an extent unknown in the case of any other metals. The blacksmith’s process of welding is to heat the iron or steel until the surface of the metal becomes pasty, and then to bring the two pieces into intimate contact by hammering on the anvil. Of late years the welding of iron, steel, copper and some other metals has been rendered possible by the use of certain electrical and chemical methods and—most important of all—by the use of the oxy-acetylene blowpipe, the process being known as “fusion welding” or “autogenous soldering,” the word autogenous implying that the process is complete in itself and independent of the use of any extraneous substance such as solder. The thermit process, of which so much has been heard, and which is briefly dealt with later, is the fusion welding of iron and steel by means of the intense heat produced by the combustion of a special chemical compound. Perhaps the oldest of the autogenous