Knowing a "hot" marina

[Barking Sands]

You're just guessing.

Galvanic corrosion and stray current corrosion have clear, identifiable pathways of electron and ion flow. The direction of that flow is what determines which is the anode and which is the cathode. It can be confusing, which is why people are often surprised that with stray current corrosion the metal fitting that has the +voltage applied to it actually becomes the anode, even though with galvanic corrosion it's the more negative metal that becomes the anode. It's all about electron flow, and with AC they're just moving back and forth and not in a steady stream like DC, which is why AC requires very high (not 4 amps) current density to cause corrosion.

Maybe. But lets just say I am not 100% convinced there is zero increased zinc loss with stray AC current over time in all cases. But amps you cite for the density you reference was also applied over meters squared in every paper I referenced. So something like 400 amps over 10 sq/ft was often cited as the energy density per sq meter required. What about 4 amps over a few sq/inches. That has similar or more current density does it not? I took those papers that cited amp density in amps applied over meters squared as a ratio to determine density...not just total amps. I could obviously be wrong, but to me it is still plausible. But I do appreciate your feedback.

 

[Steve DAntonio]

I say this routinely, corrosion is by far the most misunderstood, and misdiagnosed phenomenon in the marine industry; the amount of misinformation is simply staggering, and it's all a result of lack of professional training and education. It is the primary inspiration for the many articles I've written and lectures I've presented on the subject. Listen for the "it's a bad ground" response...

I've covered (busted) the hot marina myth many times, including here Feature: Busting the “Hot Marina” Myth – Editorial: A Blue-Collar Resurgence | Steve D'Antonio Marine Consulting

and here