Electical circuit corrosion

[gdodd]

We have a problem with an automotive wiring harness which has a number of wires containing perforations in the insulation exposing the stranded copper wires.

Two of the wires are active supplying current to two different appliances and one is an earth wire.

In exceptional cases there is a likelyhood of the convuluted tube,surrounding the wiring harness, holding water and forming a dam. When current flows the water acts an electrolyte for the exposed wires to start a corrosion cell.

The corrosion product that forms at the anode has been analysed and found to be predominantly copper hydroxide. It eventually eats through the copper strands causing the appliance to cease functioning.

A fix has been proposed of still functioning wiring harnesses, entailing removal of the convuluted tube and application of a spray on insulation compound. This compound covers the damaged areas isolating them from the atmosphere. A net tube is then applied that allows any stray moisture to run off rather than form dams in low points.

My question
Are the copper hydroxide deposits located at the exposed copper wiring likely to promote or accelerate corrosion if covered with insulating medium and isolated from the atmosphere and any moisture present. Copper hydroxide is insoluble in water.
Bare in mind that the current flowing through the wiring is in the order of milliamps and only one strand of the copper wiring is capable of carrying the imposed current without overheating.

 

[Metalguy]

In a word, no. Keep it dry and you'll be OK.

 

[TVP]

I agree with Metalguy. Is this procedure meant to fix existing cars as they need service, or is this meant to be a permanent fix for new vehicles? Or both?

 

[gdodd]

Thanks Metalguy and TVP
Answer to TVP- the former, but I am not at liberty to divulge any detail.

 

[TVP]

I'll try not to be too offended.

The reason I was asking was if it's the latter, then there are probably better ways to re-engineer a solution. Anyway, it sounds like you have a good handle on the situation. Good luck.