30 April 2015

Z is for Zinc

During April, we're participating in the Blogging from A to Z Challenge. Every day (except Sundays), we’ll be doing an alphabet themed post starting with “A is for Adventurous” and ending with “Z is for Zinc" - which is today's post! We made it to the end!!

A Snickers bar to anyone who can explain this to me.

“I would have never been a good scientist. My attention span was too short for that.” Octavia Butler (1947-2006)

Octavia Butler is one of my favorite writers. She explored issues of race, class and gender while writing about things like vampires, aliens and time travel. She also was awarded the MacArthur Foundation “genius” grant, so it just goes to show you that things like vampires, aliens and time travel aren’t such silly things to write (and read) about after all. Knowing that she didn’t have the attention span to be a scientist makes me feel so much better about myself and the fact that I dropped out of physics in high school. I didn’t have the attention span for all of that scientific mumbo-jumbo either. 

So what does all of this have to do with today’s letter – Z? Well, Z stands for zinc anodes, or sacrificial zincs. And to understand why you should care about zinc, vampires, aliens or time travel, sometimes you have to learn a little bit about science. Not to worry – I don’t have a long attention span myself, so let’s keep this short and sweet.

1 – If you own a boat, you need zinc.

You stick zinc anodes in places where you have two different types of metal that are going to be submerged in salt water. Usually, you find zincs between the propeller (which might be bronze or aluminum) and the stainless steel shaft.

2 – Huh?

This is where the science stuff comes in. Or magic. Depends upon your perspective. When you take two different metals and connect them and then stick them in salt water, you create a battery. That basically means a current is flowing between the two metals. Electrons dance back and forth, but while they do that they give up their life in the form of metal ions and disappear into the sea. The fancy term for this is “galvanic corrosion”. It is kind of like a cat shedding its fur all over your carpet. Except in this case, the fur is really your propeller and propeller shaft. If you’ve spent any time on boats, you’ll know that they work much better when your propeller is intact and attached to your boat. 

3 – This is boring. Can we talk about vampires and time travel instead? 

No, we can’t. This is what I kept saying to my physics teacher. His response, “No. Focus on these formulas related to time dilation and relative velocity instead.” I thought it was boring. Little did I know that physics actually has something to do with time travel. 

Anyway, back to zincs and why you should care. If you place a magical zinc anode between the two different metals, then you can prevent damage to the more important (and costly) metal objects. Zinc is a happy little creature who only cares about others and readily gives up its electrons more quickly than the other metals. It is kind of like the Mother Teresa of the metal world. In other words, it sacrifices itself so that others may live.

4 – But what about the planet, man?

You wouldn’t think someone like Mother Teresa or zinc would ever get a bad name, but unfortunately, zinc is now increasingly restricted and controlled in some places. Zinc is a heavy metal and contains cadmium. That’s not to say that it is pudgy and overweight. It means that when zinc sheds its fur, the stuff it leaves in the water is bad for the environment. Scientists are concerned about the pollution it is causing and its presence in the human food chain. 

5 – Those crunchy granola scientist types ruin it for everyone. Now what?

Some folks think you should use aluminum rather than zinc. The catch – it is more expensive. But there is some good news. You need less aluminum (in terms of weight) and they last longer. We’ve only used zinc anodes on our boat. (Shh...don't rat us out to the crunchy granola types.) If you’ve used aluminum, let us know how it worked out.

Want to know more? Check out this article in BoatUs and this article in Sail World.

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  1. Great post ! This is the first I've heard about the cadmium concern. In chemical oceanography, we like cadmium ! It's a micro-nutrient for phytoplankton and a good paleo-tracer of nutrient uptake. I suppose the concern is "overdoses" in coastal and estuary environments. If everyone goes to aluminum, so much the better, but anyone headed out for a long cruise better buy several year's supply since finding Al anodes in remote places will be tough. I'm not a fan of aliens or vampires, but I'll give Octavia Butler a try based on your glowing recommendation. Congrats for the A-Z challenge ! And at a time when you have a lot of other stuff going on, too ! Bravo.

    1. We just put a new zinc on our boat, so this was quite timely to write about. Although, to be fair, I did write most of my posts in advance, which was a HUGE help this month as we've been so crazy with the new boat.

  2. Love it! Actually, this is science writing at its best ... you have a serious point to make, important info, but you're not at all serious once your humor cuts in. Congrats on getting to 'zee end'!

    1. So glad you did the challenge with me! We made it!

  3. How I wish you were my Maths teacher? You made the concept so simple and you know, Maths is my nightmare. Congrats for completing the challenge.

    1. If I had been your math teacher, I'm pretty sure you wouldn't have learned too much. I probably would have tried to work M&M candies into the lessons - you know 2 red M&Ms + 2 blue M&Ms = 0 M&Ms because the teacher ate them all. It's hard to believe it is May and no more letter-themed blogs!

  4. Hubby and I have a sailboat with a small cuddy cabin. We used to sail ALL the time. Now we can't seem to find the time. It's an old O'Day Mariner, but I had no idea about the zinc. I only knew you needed a special kind of paint when you painted the bottom to keep it from getting chalky and fading away.

    Congrats on completing the challenge.

  5. That's too bad other things have gotten in the way of sailing. Your boat sounds lovely :-) I can't believe it is a new month and the challenge is over!

  6. Great choice for Z although I am with you on the boring science stuff. Vampires yes, metals no. Hubby deals with this kind of thing.

    1. It's handy to have a hubby who likes boring science stuff. Does he also like vampires?

  7. Awesome blog, I really appreciate it. Thanks for sharing useful information with us. I am looking forward to more from you. If want to know about zinc anodes so you can visit them.


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