[woodcote]

Soldering the wires to the solid metal banana plugs does require a hot iron, tinning the wire and tinning of the cavity in the end of the plug (using flux paste and plenty of solder) – and then the final joint should solder well. Once the join has cooled, give the wire a very good tug to make sure it will hold up to being manhandled on a regular basis. The ‘helping hands’ set-ups are useful for a job like this – clips to hold wires and components, plus a magnifying glass to see what you're doing. An alternative is to hold the banana plug in a crocodile clip stuck in some blu-tack. With proper tinning, the soldering shouldn't take very long and the plug shouldn't be getting too hot - but never be tempted to hold the plug in your fingers.

Now the banana plugs are attached (hopefully to the correct wires...), I have added a small cable tie to the cables going in and out of the box to prevent them being pulled from their connections in the box. I’ve pulled the cable ties nice and tight, so if I pull the cable, the tie catches on the inside of the hole in the box wall and prevents the cable being pulled any further…

   

Then I carefully compress the wires inside and close the box.