Desford Flyers
Black Wire Corrosion
The occurrence of black wire corrosion can spell disaster for a model and should be checked on an annual basis.
The quickest way to check is to perform a test discharge on your models battery whilst monitoring the voltage and wiggling the leads at the same time. I suggest a discharge rate of at least 1 amp. Ohms law R=V/I suggests a resistance of about 4.7 ohms for a four cell NiMH battery.
In the photos I have gently removed the connection pin from its holder by easing open the plastic retaining clip with a knife blade.
In my entire working life in the Electricity Supply Industry I have not encountered this problem, and Malcolm hasn't encountered it either during his years of working for BT.
I'm not a chemist but I suspect that the phenomenon is caused by chemical reaction between the copper wire and the black plastic insulation.
The quickest way to check is to perform a test discharge on your models battery whilst monitoring the voltage and wiggling the leads at the same time. I suggest a discharge rate of at least 1 amp. Ohms law R=V/I suggests a resistance of about 4.7 ohms for a four cell NiMH battery.
In the photos I have gently removed the connection pin from its holder by easing open the plastic retaining clip with a knife blade.
In my entire working life in the Electricity Supply Industry I have not encountered this problem, and Malcolm hasn't encountered it either during his years of working for BT.
I'm not a chemist but I suspect that the phenomenon is caused by chemical reaction between the copper wire and the black plastic insulation.
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