Running a cable in tight areas of the boat can be complicated. Here are a few methods.
The usual technique: the messenger
The quickest and easiest solution, when you have a cable that already runs in a tube, is to use the existing cable to run the new one:
- Prepare the right length of new cable: the length needed and a little margin on each side. Ideally, your new cable should be the same diameter as the previous one.
- Securely attach the end of the new cable to the old one with electrician's tape. Soldering or other spots may interfere with the passage. Make sure that the binding is not too thick, so as not to hinder the sliding inside the tube.
- Gently pull the free end of the old cable out of the tube, and insert the new one in its place. Ideally, this should be done by two people, one on each side.
Running a cable without a messenger: the example of the balcony
So what do you do when the messenger breaks? When we had to change the power cable of our navigation light, we were ready to lose patience!
We've been looking for a long time at how to get it from the wet well to the balcony, before coming out at the fire. Here are a few solutions gleaned from our research that may help you.
Using a thread puller
Using an electrician's wire puller, with a spring loaded needle, is known to work in this type of situation. Start at the location of the light, take the desired angle and exit into the anchor locker. Hang your wire on the needle, then pull the wire puller out to run it through the balcony.
Playing with magnetic attraction
Connect a small steel element to a thin wire, then move the assembly inside the tube from the outside with a strong enough magnet. When the wire is through, use it as a messenger and finish installing the new cable.
Make a hole at the junction of the two tubes
Another, more extreme solution is to dismantle the balcony and drill a hole in the junction of the two tubes. Through the hole, you can then direct the cable in the right direction.
While this technique has the advantage of being able to be installed relatively quickly, drilling a stainless steel tube is complicated and may weaken your balcony.
Vacuuming a wire
The solution that turned out to be the best for us was to use a vacuum cleaner.
- Prepare a spool of fairly light yarn. Connect the end of the thread to a cotton ball.
- Insert the cotton ball on one side and vacuum with the other side. In a few seconds, the thread is gone!
- Then use the messenger technique to run a larger diameter wire with greater strength, then finally run the electrical cable.
