module 4 LISTENING ARE YOU GOOD AT SOLDERING? COMMUNICATION Listen to the recording and complete the text with the words in the box. amount move components tip working end appearance solder molecular soldering iron joint soldering temperature hard flow heat film melting high Good soldering is a skill that is learnt by practice. The most important point in (a) ...................... is that both parts of the joint to be made must be at the same (b) ...................... . The solder will flow evenly and make a good electrical and mechanical (c) ...................... only if both parts of the joint are at an equal (d) ...................... temperature. Even though it appears that there is metal to metal contact in a joint to be made, very often there exists a (e) ...................... of oxide on the surface that insulates the two parts. For this reason it is no good applying the (f) ...................... tip to one half of the joint only and expecting this to heat the other half of the joint as well. When the iron is hot, apply some solder to the flattened (g) ...................... at the end of the bit, and wipe it on a piece of damp cloth or sponge so that the (h) ...................... forms a thin film on the bit. This is known as tinning the bit . Melt a little more solder on to the (i) ...................... of the soldering iron, and place the tip so it contacts both parts of the joint. It is the molten solder on the tip of the iron that allows the (j) ...................... to flow quickly from the iron into both parts of the joint. If the iron has the right amount of solder on it and is positioned correctly, then the two parts to be joined will reach the solder s (k) ...................... temperature in a couple of seconds. Now apply the end of the solder to the point where both parts of the joint and the soldering iron are all touching one another. The solder will melt immediately and (l) ...................... around all the parts that are at, or over, the melting part s temperature. After a few seconds, remove the iron from the joint. Make sure that no parts of the joint (m) ...................... after the soldering iron is removed until the solder is completely (n) ...................... . This can take quite a few seconds with large joints. If the joint is disturbed during this cooling period, it may be seriously weakened. The hard cold solder on a properly made joint should have a smooth shiny (o) ...................... . In a properly made joint the solder will bond the (p) ...................... very strongly indeed, since the process of soldering actually forms a (q) ...................... bond with the surfaces of the joint. Note that it is important to use the right (r) ...................... of solder, both on the iron and on the joint. Too little solder on the iron will result in poor heat transfer to the joint, too much solder will form strings as the iron is removed, causing splashes and bridges to other contacts. But above all, remember that anyone can learn to solder, it just takes practice! 168