What causes arcing, and what can be done?

Two Things Cause Arcing:
If the connection is not sound, the electricity tries to force its way to the other side of the connector (through the oxidation). Heat builds up and it intermittently breaks through and connects to the other side (arcs).

If the connector vibrates and makes and breaks contact, there is arcing. With the subsequent oxidation, it gets harder and harder for the electricity to flow, and over time the arcing increases, and ultimately burns (chars) the metal surface.

Solution:
On low amperage applications, using DeoxIT® along with DeoxIT® SHIELD, should do the job. If the current is high, then DeoxIT®, followed by DeoxIT® L260Cp Grease (lithium based w/copper particles) should work well.

NOTE:
DeoxIT® GOLD (formerly ProGold),
DeoxIT® SHIELD (formerly PreservIT)
DeoxIT® FaderLube (formerly CaiLube MCL)
DeoxIT® Grease Type M260 & L260 Paste (formerly CaiLube Grease).