Fragile wired doorbell cable (a diy question)

[Peter Johnson]

I'm trying to replace a wired doorbell but after nearly 40 years of (concealed) expose to extremes of temperatures the wire is fragile. One terminal is just long enough to connect but I can see a crack in the cable, the other is now too short, there are cracks in the cable and the wire that I exposed earlier has already broken off. Has anyone any ideas on how to proceed, and restore the function of the wired bell, or must I abandon it in favour of a battery device? I've had to remove the bell and protect what remains of the wire from the elements with a piece of Duck tape. Thanks in advance.

[Theo]

Can you get access to some part of the cable to splice in a replacement piece? eg if it's the outside part that has corroded, can you replace the outdoor section? Where does it go after leaving the doorbell?

Doorbells don't need anything fancy in terms of cabling, so any cable of a similar or greater thickness of metal should do.

Theo

[John Rumm]

If replacement of the cable is not an option. then I would carefully strip the ends of the wires you have - perhaps cutting back to a more sound bit, then solder on extensions, and protect the joint with heat shrink to add insulation and mechanical protection.

[Peter Johnson]

The cable vanishes into brickwork and I do't know its route to the transformer and bell. See my reply to John for my current strategy

[Peter Johnson]

I had thought about soldering but am unsure about doing it outside. Will the ambient temperature render the soldering iron less effective? In the meantime, I've been on eBay and ordered a sample length (.25m) of bell wire, and some gel crimp connectors. So now I have choices.

[John Rumm]

Not in any meaningful way.

Yup gel crimps are fine - although a bit more bulky and difficult to hide than a soldered connection. You will need to take care when crimping if the wire is fragile.

[alan_m]

OK in a sheltered location but I've found that trying to solder, with a low wattage soldering iron, in a windy location is problematical.

The insulation on bell wire will probably shrink back a lot with the heat from a soldering iron so make sure that you put some sleeving or heat shrink tubing on you new bit of wire before soldering so that you can slide it up to insulate the bare soldered wires. The main problem with old wire is that it may/will be oxidised and cleaning it back to shiny copper so that solder will take could be almost impossible if you don't have much access to the ends of the wire.

[Scott]

I have the same problem. The bell still works but the chime is falling apart. I wanted to fit a new chime but the cable - which is apparently Vulcanised India Rubber (VIR) or possibly cloth covered - is effectively painted in and probably too short. I cannot see a transformer or any batteries for that matter. I would like to replace the whole cable but I cannot see a way of doing this. The bell push is 'heritage'.

I know VIR is less of an issue for low voltage but if there is a transformer involved, could this create a danger if there is a short circuit?

[Peter Johnson]

The bell wire and crimps came in today's post so I got the soldering iron out. Doorbell service is resumed! (Crimps in stock for possible future use.)