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Sailboat Owner's Guide to Corrosion - Basic Theories (Collier 1-4)

Oct 19, 2017
6,850
O'Day 19 Littleton, NH
Welcome to our SBO Book club study of Everett Collier's book, 'The Boatowner's Guide to Corrosion".

We will be reading and posting, in sections, as we work our way through the subject of corrosion in the marine environment. Each section will cover one or more chapters and be posted in its own thread. As the new threads are started, I will tag any interested participants and create a linked table of contents to make it easier to follow along and participate.

A rough outline of the sections to come are as follows. They may be edited and updated as the current of our discussion requires.

Sections
  1. Sailboat Owner's Guide to Corrosion - Fundamentals (Collier 1-4)
  2. Sailboat Owner's Guide to Corrosion - Self-Corrosion (Collier 5)
  3. Sailboat Owner's Guide to Corrosion - Galvanic and Stray Current Corrosion (Collier 6 & 7)
  4. Sailboat Owner's Guide to Corrosion - Metals Aboard (Collier 8 - 12)
  5. Sailboat Owner's Guide to Corrosion - Protection (Collier 13 - 15)
  6. Sailboat Owner's Guide to Corrosion - Hull and Motor (Collier 16 - 17)
  7. Sailboat Owner's Guide to Corrosion - Electronics and Plumbing (Collier 18 - 19)
  8. Sailboat Owner's Guide to Corrosion - Topsides (Collier 20 - 21)
  9. Sailboat Owner's Guide to Corrosion - Resources

Let me know (@Will Gilmore) if you want your name added to this list. It will appear at the beginning of each new thread to let interested members know when the new thread has opened. You can then post something or click the [Watch] button to follow the thread.

Tagged participants:
@Will Gilmore
@DArcy
@mermike
@jssailem
@dlochner
@dLj
@JamesG161
@ontherocks83
@rgranger
@Mark Maulden
@Davidasailor26
@LeslieTroyer

I'll be happy to edit/update this list at any time. Just let me know @Will Gilmore

Here is a link to the Amazon listing for an inexpensive used copy of Collier's book, in case you don't have it yet. The Boat Owner's Guide to Corrosion


Some basic rules for maintaining useful and topic focused discussion:
SBO is a public forum, and as such, anyone interested, is welcome to participate, ask questions and express their opinions. There are limitations to the form these expressions can take and the culture of participation. All the basic forum rules of decorum and good manners apply. As a participant in this series of discussions, we would ask that participants remain on topic and refrain from derogatory language or remarks. The express purpose of this series of threads will be to understand corrosion in the marine environment using Collier's book as a guide. We therefore, expect participants to make an honest effort to read and stay up on the material under discussion. We are a group of congenial sailors with a sense of humor that often can run astray. A playful comment on occasion is expected, but anyone of us will feel free to firmly redirect anyone back to the subject at hand if it looks like it is in danger of derailing the discussion. A moderator will be asked to intervene, edit out any inappropriate comments, and possible ban an offending participant, should the group find their continued presence a serious distraction. Posting in this thread will be considered agreement to these terms. Thank you so much for your understanding and cooperation. I look forward to being part of the amazing community that is developing around this subject. I know we will all have a great time.

-Will (Dragonfly)
 
Oct 19, 2017
6,850
O'Day 19 Littleton, NH
Anyone who has any improvements to suggest to the above introduction, please let me know. I want this to go as smoothly as possible. :beer:

-Will (Dragonfly)
 

dLj

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Mar 23, 2017
1,758
Belliure 41 Snug Harbor, Lake Champlain
Tagged participants: @Will Gilmore @DArcy @mermike @jssailem @dlochner @dLj @JamesG161 @ontherocks83 @rgranger @Mark Maulden @Davidasailor26

So should we include the list of participants as above each time we post? The post heading is the top of this thread. My book should be arriving next week and I will then take a look at it and see what the first 4 chapters look like. Are we putting a time frame on posting to this chapter? How will we consider it closed and move onto the next chapter? Anyway, sounds like an interesting way to do this and I look forward to the discussions.

dj
 
Oct 22, 2014
15,695
CAL 35 Cruiser moored EVERETT WA
Great :plus:

Not sure it necessarily needs to be "Closed". It could be by consensus that you move on to Discussion 2. The discussion 1 can stay open for new participants to come join the experience. Starting at discussion 1. It would be possible for a member to go back and help new participants with questions.
 
Oct 19, 2017
6,850
O'Day 19 Littleton, NH
Not sure it necessarily needs to be "Closed". It could be by consensus that you move on to Discussion 2. The discussion 1 can stay open for new participants to come join the experience.
That's my thinking as well.


So should we include the list of participants as above each time we post?
I think at the start of each thread should be enough to get everyone's attention. Once they check in, they can post or click 'Watch' to follow.

-Will (Dragonfly)
 

dLj

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Mar 23, 2017
1,758
Belliure 41 Snug Harbor, Lake Champlain
I've read these first 4 chapters and the author has done a pretty good job of summarizing a number of complex concepts into very few pages. Not an easy thing to do. The first chapter, 'Basic Molecular Theory' introduces the concept of the atom, a bit on electron orbitals, two important chemical bonding mechanisms; covalent and ionic bonding. The chapter is not quite 3 pages long so not a lot of info, but a nice refresher within the context of what one may need to know at this level. If anyone reads this chapter, has any questions, please post them and we'll try to answer whatever questions may arise.

Chapter 2 is 'Basic Chemical Theory', and it begins to get a bit more detailed. It's 6 pages long, so again, it's pretty superficial in this arena, but not a big need for deeper understandings here. I do think it may be nice to tie this chapter into the periodic table and he also introduces the concept of the mole, but I think a bit more explanation on this may help. His table 2-1 is a bit misleading, it took me a bit to understand what he was doing. He make s leap likely for space efficiency that I think is a bit confusing. So, first the periodic table:
 

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dLj

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Mar 23, 2017
1,758
Belliure 41 Snug Harbor, Lake Champlain
So here is the short guide of what that table has for each element:

1581834347909.png


The atomic number, 58 in this case, indicates the number of protons in the nucleus of the atom. That is how each element is defined. In the concept of mole that the author talks about in the book, he skips over the AMU - atomic mass unit. The standard atomic weight that is under the elements name, 140.12 is in the units of AMU. The atomic weight is the sum of the proton and neutrons in the nucleus of the atom. Each proton and each neutron weighs 1 AMU (well, close enough for this discussion). Each element has several isotopes commonly found in nature.

Let me use carbon as the example both because I know it fairly well and because it is the element the atomic weight units are based on (as you can see in the bottom where it says "Based upon 12C" (sorry can figure out how to make a super script)... The atomic weight of carbon is 12.011 per this periodic table.

Carbon is Atomic number 6. So it has 6 protons in the nucleus.Carbon has three isotopes: carbon 12, carbon 13 and carbon 14 found in nature. Carbon 12 has 6 protons and 6 neutron, carbon 13 has 6 protons and 7 neutrons and carbon 14 has 6 protons and 8 neutrons. These three have different percentages found in nature with carbon 12 being by far the most common. So the Standard Atomic Weight of each of the elements is the weighted average of the different isotopes present in nature.

Now, to work with elements at our scale, we need a method to measure them in the lab. That is where the mole comes in. It turns out, if you weigh out an element in grams to the Standard Atomic Weight, but in grams, so above if you weight out 140.12 grams of Ce or if you were to weigh out 12.011 grams of carbon - in both cases you would have the same number of atoms in both measurements. That's Avogadro's number 6.0221 X 10 to the 23rd power - or 1 mole each of Ce and C. Whew, Hope that makes sense....

Chapter 3 is "Basic Electrical Theory" and I don't have comments in that chapter. So anyone with questions there, ask.

Chapter 4 "Basic Corrosion Processes" - I have a lot of comments on but I'm going to leave that for another day as it's now 2 o'clock in teh morning my time and I"m going to bed.

dj
 
Feb 14, 2014
5,560
Hunter 430 Waveland, MS
So here is the short guide [Ce]
A Corrosion key is also shown on the bottom as 5.5386.[Ce]
That is Ionization Energy (eV).
Simply put, the energy to need to lose an electron or oxidize.

Note: Fe = 7.0925 eV and Zn = 9.3942 eV

Fe will oxidize faster[easier] than Zn in Air.
Jim...
 
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dLj

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Mar 23, 2017
1,758
Belliure 41 Snug Harbor, Lake Champlain
So, before I get into talking about Chapter 4, I'm looking for a dictionary on corrosion. I picked up one from NACE International. NACE stands for National Association of Corrosion Engineers. It is now an international organization. You can go to their website and register, this dictionary is on-line and free, but it goes letter by letter. So I printed them all out and combined them into one .pdf to put here so it's easier for folks to reference it. Sorry,, all the headers and footers from the web version is attached, but you can at least search it.

dj
 

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dLj

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Mar 23, 2017
1,758
Belliure 41 Snug Harbor, Lake Champlain
In chapter 4, the author defines three types of corrosion: Simple Electrochemical Corrosion, Galvanic Corrosion, and Electrolytic Corrosion.

The first and last terms are non-standard terms used in corrosion, at least by NACE standards and all other references/standards that I'm aware of. Galvanic corrosion is an accepted term. I've just joined ABYC to see if they have defined terms that are unique to boating. But I have to wait until my membership clears or the database is reset with my credentials to get into their standards. So I can't comment on that at this point.

The term Simple Electrochemical Corrosion, as defined by the author, seems to be aimed more at basic corrosion theory.

The term Electrolytic Corrosion is an incorrect term, but the author does identify what he is talking about is specifically Stray Current corrosion. See the NACE dictionary: "electrolytic corrosion—not a proper term, but sometimes incorrectly used to refer to galvanic corrosion, stray-current corrosion, or any form of electro-chemical corrosion." Again, I'm going to see if ABYC has any unique definitions specifically aimed at the boating industry. I'll be back on that one once I get access to the ABYC standards.

I don't think this is particularly important from a conceptual point of view, but I do feel it is important to begin using correct terminology. One of the things that becomes very difficult is trying to answer questions that are using the wrong terms as first one must determine what the actual question is referring to. Concepts and terminology are critical to have a clear understanding for efficient conversation, IMHO.

dj
 
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Mar 23, 2017
1,758
Belliure 41 Snug Harbor, Lake Champlain
Will,

NACE does a whole lot more than just cathodic protection. It's the premier internationally recognized organization dealing with corrosion from trainings, certifications, standards and a lot more.

dj
 
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dLj

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Mar 23, 2017
1,758
Belliure 41 Snug Harbor, Lake Champlain
I've gotten access the ABYC standards and there are none dealing with corrosion definitions. They have one standard on cathodic protection. Nothing in those standards contradicts what I said above.

So what would folk like to talk about? The explanations in chapters 1 through 4 are pretty well done given the limited amount of space for a book like this (with the exception of terminology).

There are lots more details surrounding corrosion theory but I'm not sure we need to go into that here. But I'm not opposed to delving into deeper levels.

dj
 
Oct 19, 2017
6,850
O'Day 19 Littleton, NH
My book hasn't arrived yet, so I am not familiar with Collier's coverage of the basics.
Chapter 1 is titled: Basic Molecular Theory.
Chapter 2 is titled: Basic Chemical Theory.
Chapter 3 is titled: Basic Electrical Theory.
&
Chapter 4 is titled: Basic Corrosion Processes.

Starting with basic molecular theory, I would like to know why some molecules hold electrons more loosely than others and why a molecules will try to strip electrons from another.

-Will (Dragonfly)
 
Feb 14, 2014
5,560
Hunter 430 Waveland, MS
I would like to know why some molecules hold electrons more loosely than others and why a molecules will try to strip electrons from another.
Will , try Atoms, not molecules.

Molecules share electrons via a chemical bond.
Example: Sodium Chloride [NaCL] is a molecule of 2 Atoms, which share electron [1]

Are we sure this is the chemistry depth necessary?
Jim...

PS: Calcium needs two electrons for stable CaCl2.
 
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dLj

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Mar 23, 2017
1,758
Belliure 41 Snug Harbor, Lake Champlain
Collier does cover this to a small extent in those chapters. The nutshell answer it is has to do with the electron orbital structure. There are distinct shells, or orbitals where electrons will reside. Look at the periodic table I posted above. As you move from left to right, you are filling up distinct energy shells. So top row, you have first H, with the 1s designation - meaning, there is one electron in the S shell. the next atom to the right is He. It has a 2s. The S shell, closest to the nucleus is filled with two electrons. So hydrogen is much more prone to either give up or get (share) and electron as the S shell is not filled. Helium is pretty much inert as that shell is filled. Now, go down to the next row, starts with Li. Li stars filling the next S shell, Be has that shell filled. As you move across to B, C, N, O and F you see the next sheel, the p shell is being filled, arriving to Ne where both s shells and the p shell is filled. Again, Ne is pretty much inert. This goes on and on as you move across and down the periodic table with more and more electron shells being filled. Each of these shells gets further from the nucleus so they are generally easier to ionize. Elements towards the left side tend to give up electrons, elements on the right side tend to acquire electrons - those in the middle may do both. Real general rule of thumb there...

But you asked about molecules. that gets rather more complicated. I'm not sure at this stage if we really want to go there?

dj