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What is the likely corrosion here?

Bleep Bleep

Bleep Bleep

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70 Charger. Recent purchase. Plug wire ends and distribution cap shows quite a bit of some colored residue.
Planning on replacing plugs, wires, distributor.
But curious if there are any broader implications elsewhere based on cause?


IMG_3616.jpeg
 
Just guessing but I imagine moisture got in and corroded the zinc plating. I've seen that before on cars I've worked on. To prevent that, I'd say better quality terminals/distributor cap, and coat with dielectric grease.

Here's Google AI info: (bottom paragraph for zinc coated steel)

Powdery corrosion on electrical contacts is a serious issue that can significantly affect the performance and lifespan of electrical components.
Here's a breakdown of its causes, types, materials affected, effects, and solutions:
Causes of powdery corrosion
  • Exposure to elements: Moisture, salt, dirt, dust, and corrosive chemicals are the primary culprits.
  • Dissimilar metals: When different metals with varying electrochemical potentials are in contact in an electrolyte environment, galvanic corrosion can occur, resulting in a powdery substance.
  • Fretting corrosion: This occurs in tin-plated connectors due to micromotion (vibration, temperature changes) and low contact pressure, leading to the buildup of tin oxides, a powdery substance.
Types of powdery corrosion
  • White powder: Often seen on battery terminals and indicates the presence of lead sulfate (corrosion of the negative terminal) or potassium carbonate (leakage from alkaline batteries).
  • Green/blue powder: Indicates copper sulfate, which is copper corrosion.
  • Sulfur corrosion: Forms silver sulfide on silver contacts in the presence of sulfur in the air, creating a high-resistance layer.
Materials susceptible to powdery corrosion
  • Copper: Commonly used in wires and cables, it can corrode over time, especially in damp environments.
  • Tin-plated connectors: Vulnerable to fretting corrosion, leading to oxide buildup.
  • Zinc-coated steel: Zinc corrodes into a white powdery substance (white rust) when exposed to moisture.
  • Silver-plated contacts: Susceptible to sulfur corrosion.
  • Battery terminals: Especially the negative terminals.
 
I would expect a humid climate to have some amount of gunk like that especially is some sort of grease were used.
 
OKDart said:
Just guessing but I imagine moisture got in and corroded the zinc plating
Click to expand...

Kern Dog said:
I would expect a humid climate to have some amount of gunk like that especially is some sort of grease were used.
Click to expand...
Previous owner did tell me that he had tried some type of storage (‘tent’) which had created moisture. So this is probably very likely cause.

Lefty71 said:
I assume the cap does NOT have brass terminals??
Click to expand...
No they aren’t so I need to find a higher quality cap and wires.
 
I use a little dielectric grease on everything electrical anymore.
 
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