Classic blackwire example

[Cuban8]

Continuing with my pre-season checks, I've just come across this .

Typical blackwire on a 4 cell Nicad pack dated 2008. It's a non-flight pack that I use for set up & test as I stopped using 4 cell packs ages ago. The battery had been allowed to remain flat for some time but whether that contributes to the cause is a moot point. I've never come across B/W on any Nimh cells, but I still check for it all the same. The blue corrosion on the crimp was very noticeable, but not always so on some I've seen in the past, so take a very good look with a magnifying glass for anything abnormal. As you can see the problem has travelled from the battery -ve along the wire to the connector - the strands are dull and very brittle. The +ve is unaffected.

Many of the 'old hands' on here will be well aware of the dangers, but for those that haven't seen  an example of a 'model wrecker' or maybe are still hanging on to old packs, this is a timely reminder.

 

 

Edited By Cuban8 on 27/02/2017 10:30:42

[bert baker]

Yep been there, I lost my Tigermoth to black wire syndrome on a switch harness

[Cuban8]

Not only Rx packs, but Tx as well, don't forget. It's a weird phenomenon that has been known to travel from battery, through connectors, switches etc right along to the pcb in a tranny.

Edited By Cuban8 on 27/02/2017 10:38:26

[Dwain Dibley.]

Good post..!!

Nice one cuban8.

D.D.

[Engine Doctor]

A timely reminder . Must do the usual reminder to club .

[J D 8]

The same blue corrosion can often be found on your car battery terminal and will destroy it in time. Baking soda in a cup of water and an old toothbrush will remove it. Wear protective gloves,dry then coat terminal with vaseline.

[Former Member]

[This posting has been removed]

[MaxG]

I have had it in the past and always check for it.

One thing I do in spring is to go into all my models and unplug and replug all the servos and switches from the Rx. I feel that this at least disturbs any slight corrosion that may have happened on these pins and sockets over the last year. Not necessarily black wire because I do not leave any batteries in unused models but from just general damp conditions that may occur in the loft or garage.

I once had to throw away a cordless drill that had corrosion on the battery tabs after being left in a damp shed so do only check your model stuff!!

HTH

Maxg

[Former Member]

[This posting has been removed]

[Cuban8]

Not sure about the storing in damp conditions theory, as the battery in my photo had been stored indoors for several years in a centrally heated room that I use for building.

[J D 8]

There is always some moisture in the air even if it's only from your breath and as you have found it is just a matter of time before corrosion sets in.

[Nightflyer]

There have been many discussions over this problem over the years. Some of the 'preventions' are not true while others do work. I have had packs that give this problem and others that don't either rc ones for tx or rx, or NiCad or Nimh ones.

Some of the resilience to the problem (not the cure) is the quality of wire used. Tinned copper wire is better than copper wire but does not prevent it (ask a fast electric model boater most still have the same trouble).

However, if you are talking about protecting your radio equipment as a rule of thumb I will always disconnect the battery packs in the models and also in transmitters if I am not going to use them for a few months. If you do not, the corrosion will not stop at the battery pack connector it will continue through wiring harnesses, switches, and transmitter or receiver circuit boards. I have seen many examples of this over the years from other modellers either at the field who have problems or after they have had a model crash as a consequence of the resultant failure of the equipment.

At the end of the day follow manufacturers instructions about safe storage, care and handling of the equipment and the batteries.

[Cuban8]

True story................

Many years ago I was giving a chap a flying lesson on his trainer (pre buddy box and failsafe days) and he panicked after the model began looping on its own. I took the Tx and sure enough, the model was performing perfectly round loops, each getting lower to the ground and with no effect from any control input.

After several loops, the model made a fast greaser of a landing, wings level, in the outfield longer grass - undamaged.

Tranny was dead and on inspection, was riddled with blackwire from battery to the main board.