Soft or weak soldering is: soldering with soft or weak, i.e. fusible, solder consisting either of pure tin or of alloys of this metal with lead and bismuth. You can read about the types of soft solders and their use in our article.
Solders:
Here are a few of the most used soft solders:
A) 2 parts1 of tin and 1 part of lead – the solder is called tretnik;
B) 3 parts of tin and 2 parts of lead; both of these solders are very often used by tinsmiths;
C) 2 parts of tin and 3 parts of lead – for soldering lead;
D) 1 part of tin and 2 parts of lead – for soldering pewter articles;
E) 1 part of tin and 3 parts of lead – for filling joints of water and gas pipes, etc.;
F) 5 parts of tin, 3 parts of lead and 8 parts of bismuth – known under the name of Darier metal;
G) 1 part of tin, 2 parts of lead and 2 parts of bismuth.
Sometimes sheet tin is used as solder (the weakest).
In general, the more tin in the solder, the weaker it is (easier to melt); conversely, excess lead makes the solder stronger (harder to melt).
flux:
Fusions, or fluxes in soft soldering usually serve: rosin, ammonia, wood oil (known as gallipolskogo), sometimes lard or stearin, for zinc – hydrochloric acid (as. muriaticum), for hard metals (copper, brass, iron) – zinc chloride.
Soft solder soldering operations:
Solder soft solder can be in general not all metals, they can firmly connect only fusible metals, as the difference in fusibility between them and refractory metals (copper, iron, silver, gold and others) is too great.
