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The good/bad/ugly and the ‘ bead game ’

Some bad examples and a good one

So far, I ’ ve only shown you well-done work – it looks the way it ’s supposed to look. But how will you know what to avoid if I don ’t show you some examples of bad work? Sloppy, shoddy work that no one will admit to doing, but that somehow occurs all too frequently.

You ’ ve seen the good – and there ’s plenty more of it in Section 3, the modules on specifi c connectors. Here is a brief ‘ rogue ’s gallery ’ of common mistakes. Or maybe I should say ‘ come on missed takes ’ ?

After the ‘ bad guys ’ I want to talk about a technique called ‘ beading ’ . It ’sdescribed in some of the connector modules, like 3.3 (mini-male guitar plug connectors) and 3.7 (TT male connectors), but if you don ’t read those modules you might miss it. And beading is an important technique; sometimes it ’snot possible to add solder while heating a conductor – the strands of the conductor have to carry an extra ‘ payload ’ of solder. That ’s what beading is for.

But back now to our ‘ usual suspects ’ , the most common errors of bad soldering – the typical villains. And after I show you all the wrong ways, I ’ ll show you a good solder connection to inspire you.

Hehe, sure is too much solder there in Figure 2.1.1 , right? That elephantine blob of solder, looking like a large metal goiter, may be exaggerated, but I ’ m trying to make a point. Use only enough solder to fi ll the solder cup, allowing for the amount of solder that the wire will displace when it ’s inserted into the solder cup – not too much solder, not too little.

2.1

Figure 2.1.1 Too much solder.

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Speaking of too little solder, a classic example is seen in Figure 2.1.2 . This solder job has another problem too. The conductor has too much exposed metal. The insulation should go right up to the edge of the solder cup.

Figure 2.1.3 Exposed metal.

Figure 2.1.2 Too little solder.

An even more extreme case of ‘ too much exposed metal ’ is illustrated in Figure 2.1.3 . This weakens the solder joint and can short to adjacent conductors.

In Figure 2.1.4 the insulation has been inserted too deeply in the solder cup. This can cause contamination of the solder joint with the plastic of the insulation, degrading its conductivity. Not too deep, not too far outside the cup either. Remember Goldilocks and the three bowls of porridge? There ’s a position that ’s ‘ just right ’ .

2.1 The good/bad/ugly and the ‘bead game’ 75

See the gray, mottled color/texture of the solder in Figure 2.1.5 ? That ’sa sure sign of a ‘ cold ’ solder joint. It is physically weaker and higher in resistance than a properly done connection. If one of your joints looks like this, it won ’t help to add more solder! Instead, you have to take all the old solder out and re-tin the solder cup with fresh solder. Once solder has been overheated, or re-re-re-reheated, its conductivity and strength are degraded. It must be replaced.

Figure 2.1.5 Cold solder joint – 1.

Figure 2.1.4 Insulation too deep.

A cold solder joint isn ’t the only problem in Figure 2.1.5 . There ’s too much exposed metal and the solder distribution in the solder cup is uneven – too much on the right-hand side and not enough on the left-hand side.

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To top it all off, the conductor ’s been overheated – we can see the insulation beginning to melt back.

Figure 2.1.6 is another shot of our cold solder joint, along with the other ways this connection is troubled. See the gray color compared to the bright silver on the other solder cups?

Figure 2.1.6 Cold solder joint – 2.

It ’s not hard to burn the insulation on conductors ( Figure 2.1.7 ) – just leave your soldering iron in the wrong place for a few seconds. It ’s a lot harder to fi x it once burned, and requires thin diameter heat-shrink, along with a heat-shrink gun.

Figure 2.1.7 Insulation burned.