The beginner will find information about hard soldering, its uses and methods very useful. Hard, or strong soldering, is used where it is necessary to firmly connect refractory metals (iron, steel, copper, brass, silver, gold, etc.), is made with the help of hard or refractory solder.
Tools and fixtures for hard soldering:
The essence of hard soldering is the use of refractory solders and higher temperatures.
A soldering iron is no longer suitable for hard soldering, as it gives too little heat. For small things it can of course be used – but it must be the most powerful. Large objects are soldered on red-hot coal, the heat of which is supported by a blowing fur; when soldering not very large objects, the fur can be successfully replaced by an opahal of goose feathers.
Coal is cheaper, but its sulfur content makes it unsuitable for iron and steel, and in general it should be used carefully and only by an experienced solderer, and it is not very convenient in home conditions. For the same reason luminous gas is not suitable for iron and steel.
Charcoal (from dense wood) is therefore preferable to any other fuel, especially for amateurs. For soldering, ordinary blacksmith’s pots are used; portable pots are very convenient for this purpose, one example of which is.
Solders:
There are many hard solders, but between them you should choose the one suitable for the metals in question – in terms of color, melting point and affinity.
The melting point of the solder should be possibly closer to the melting point of the metals to be soldered, BUT! a few degrees lower! otherwise the solder may melt the metals to be soldered.
Here are a few solders for copper, iron brass, steel and bronze in descending order of their fusibility:
A) 2 parts of copper and 1 part of zinc;
B) 5 parts of good brass and 1 part of zinc;
C) 1 part copper and 1 part zinc (this solder is known as copper or strong); all three – for soldering copper or iron;
D) 16 parts of copper, 1 part of zinc and 1.5 parts of tin;
E) 13 parts of copper and 11 parts of pure silver;
F) 1 part copper, 1 part brass and 19 parts pure silver;
G) 5 parts brass, 5 parts zinc and 5 parts pure silver; the last four solders are for brass, but solder “E” is very good at soldering steel.
A good solder for copper (red) and iron is brass.
Brass is a good solder for copper (red) and iron, and iron can also be soldered with pure red copper.
Soldering fins:
Powder of borax placed in water to form a liquid dough (rubbed on a marble, glass or aspid board) is usually used as a glue for hard solders.
borax powder, placed in water to form a liquid dough (rubbed on a marble, glass or aspid board), a thin layer of which is covered seams or soldered surfaces with a badger brush (or a feather beard). Glass is occasionally used as a fin.
Methods of soldering with hard solder:
The pieces to be soldered must of course be, for the duration of soldering,
tied together in a fixed position and, if possible, arranged
on a firm, immovable support, which may be a piece of hard coal, a refractory brick, a piece of pumice, and a piece of cobblestone.
hard coal, a refractory brick, a piece of pumice, etc. Some things, such as rings, can be held over the fire by the end of the wire that binds them. Holding soldered objects with pliers is best avoided, as pliers take up a lot of heat.
It is very convenient to solder small things on artificial bedding prepared in the following way: hollow out a hollow in a fireproof brick in the shape of the one shown.
a hollow in a fireproof brick in the form shown, fill the hollow with
with a dense dough made of 2 parts (by volume) of fine charcoal powder and 1 part of finely ground refractory (or porcelain) clay, thoroughly mixed first with each other and then with a porridge made of 1 tablespoonful of rice flour.
Hard soldering of large items:
Hard soldering of large objects requires, above all, that they be
to be joined with the strongest possible seam. The most suitable seam is the “seam-in-seam” seam, which binds even stronger, but it loses too much material and can reduce the strength of the parts to be soldered.
reduce the strength of the parts to be bound. There is also a so-called serrated seam – it is convenient for joining pipes and generally cylindrical parts. In some cases, any other types of seams may be useful, and here, as well as in soldering in general, the more precise and tightly fitted the seams are, the stronger the joint.
One or two thin rivets can contribute greatly to the bonding and seaming of a joint, but care must be taken with them – not to make them larger and thicker than the thickness and other parameters of the piece being soldered allow.
