Electrical equipment in coastal Hawaii does not usually fail because it was cheap. It fails because chloride-laden air finds every unsealed opening and quietly turns metal connections into resistance.
Where corrosion actually starts
Not on the outside. The visible rust on a meter can is cosmetic. The damage that matters happens on the aluminium and copper terminations inside the panel, on the lugs of the main breaker, and on outdoor receptacle contacts.
Corroded connections increase resistance. Resistance generates heat under load. Heat accelerates corrosion. It is a loop that runs slowly for years and then fails quickly.
The five things to check on a coastal property
Outdoor receptacles: the in-use bubble cover should close over a plugged-in cord, not just over an empty outlet. Flat snap covers are not adequate for exposed locations.
The panel interior: green or white powder on lugs, discoloured breaker terminals, or a panel cover that is stiff to remove.
Exterior light fixtures: corroded sockets are the usual reason a fixture works intermittently.
The service entrance and weatherhead: cracked insulation and rust streaks below the drip loop.
Anything connected to a pool, spa or irrigation system, where salt exposure and moisture combine.
What slows it down
Sealing unused knockouts properly. Antioxidant compound on aluminium terminations. Weather-rated enclosures rather than indoor boxes with a cover screwed on. Stainless or coated hardware on exterior mounts. Periodic thermal checks of the panel under load, which show hot terminations before they show damage.
None of that is exotic and none of it costs much at installation time. Retrofitting it after a failure costs considerably more.
When replacement beats repair
A panel with corrosion on the bus itself, rather than only on the lugs, should be replaced. Bus damage cannot be cleaned back to a reliable connection, and breakers seated on a pitted bus will run hot no matter what breaker you fit.
The same logic applies to any outdoor box that has held standing water. Dry it out and it works. It will not stay working.