Thinking Like a Scientist.

Corrosion is always occurring in one way or another. It's a natural, ongoing process that all metals are subjected to.  In our last post, we discussed the forms of corrosion that boaters, divers, techs, and engineers in the marine industry are likely to encounter.  We're going to be diving into each of those in more detail in the coming weeks, but there's an important concept here that we want to zoom in on first.  Each iteration of the corrosion process is largely invisible - you can't see ion flow, of course.  In order to get ahead of corrosion, you'll need to think like a scientist.

Now, this advice is particularly necessary for technicians and for anyone undertaking a survey with a Corrosion Reference Electrode.  But it's a great mindset for everyone, and a necessary one to take with you for everything we'll be discussing on this blog.  So before anything else, let's break this idea down first.

When corrosion crosses over from the invisible into the visible, that's when you need to commit to being open-minded.  Don't assume anything at the outset.  The first thing you're tasked with doing is to observe.  Take note of any and all patterns.  Consider as much context as you can for what you're looking at.  Before long, you'll develop a hypothesis, which you can put to the test.  Testing will reveal more information, allowing you to adjust your initial theory as necessary.  Repeat, furthering your understanding.  Ultimately, you'll be able to draw a conclusion which will allow you to address the problem.  That's the Scientific Method.

Let's run through those steps in order with a quick hypothetical scenario.  The point here is to think clearly and critically.

Say you've been fortunate and have never really had to worry about corrosion on your boat before.  Keeping up with your anodes has been enough.  And let's assume here that every year, the yard replaces them for you, using the correct alloy for your environment.  Usually, there's a decent amount of material left when they go to change your zincs, but this year's different.  When they swap them out this year, you're told that your anodes were nearly completely gone.  Before panic sets in, you stop and you think.  There's no evidence of damage beyond what's happened to the anodes.  You reason that you were on the water a lot more this season than in years past.  Not only that, but this year the water was a good deal warmer than usual.  Could those two things account for the anodes depleting so much more than you expected?  They sure could - immersion time and water temperature are, as we'll learn, two constant variables on an anode's longevity.  Your boat launches with new anodes, and a check of your hull potential with a silver/silver-chloride reference cell shows that your boat is indeed properly protected.  You cross your fingers that you'll get as many days out on the water this year, so you bring along a hanging anode for good measure and you’re on your way.

Conclusions were not leapt to, the problem was understood, and an appropriate course of action was taken.

How about one more? Same situation, but this time it's discovered that all the anodes on the port side are gone. It’s a different story on the starboard side, where the anodes look pretty much like what you’d expect after a season of use. Could immersion time and water temperature explain this one? No, in this case they could not. This asymmetric pattern suggests current in the water, resulting in electrolytic corrosion.  Assuming otherwise could have disastrous results. This is a problem that needs to be taken seriously. The source of the current needs to be investigated.

Two very quick and simple examples.  Still, this is hopefully enough to illustrate the idea that preventing and combatting corrosion means understanding what you're dealing with.  We’re always here to help in that regard, so feel free to reach out if you have any questions. Next time, we’ll get into more detail about simple corrosion, so be sure to check back for that.