Barnacles on Anode

[coreng]

Don't know what I am supposed to answer to such an affirmative claim...

Get a galvanic scale perhaps? Referring to Ag/AgCl of course...

Because potentials are not given vs SHE (standard hydrogen electrode - you could'nt get one in your boat!) but vs AgCl electrode.

READ and LEARN (corrosion) before complaining and just do as you feel...

PS MgDuff (you know, the one you trust) technical data on zinc anodes : Potential Ag/AgCl = -1.05 V. Could they be wrong?
http://www.mgduff.co.uk/technical-downloads/English/ see Zinc Hull Anodes...

 

[makingplansfor]

The boat is back in the water next week, is my paint going to "bubble" if I refit the hull anode? I struggle to understand (with my basic understanding of things galvanic) how the paint and hull will be affected. Again - can one have too much zinc in the water?

 

[VicS]

Don't know what I am supposed to answer to such an affirmative claim...

Get a galvanic scale perhaps? Referring to Ag/AgCl of course...

Because potentials are not given vs SHE (standard hydrogen electrode - you could'nt get one in your boat!) but vs AgCl electrode.

READ and LEARN (corrosion) before complaining and just do as you feel...

useful galvanic series at http://64.224.111.143/handbook/galv_series.htm

(potentials related to a saturated calomel electrode are the same as those related to a silver/silver chloride in seawater for all practical purposes)

before dismissing my post and dispensing the advice to "read and learn" I suggest you read my profile.
( I am a Member of the Royal Society of Chemistry

 

[coreng]

I have no information on your boat but the only guess I do is it's a GRP, so, no worrying for antifouling.

For the rest I don't need to guess, I just need a measurement.

 

[coreng]

Vics,

I never attack first. You are making a mess about electro-negativity and you produce electro-negative values that are the same as the one published in white paper (OK for Calomel but you won't have one in your boat, either).

Furthermore, Magnesium, Aluminium and Zinc are top ranked in electro-negative potential.

So, what's the mess about?

 

[VicS]

The boat is back in the water next week, is my paint going to "bubble" if I refit the hull anode? I struggle to understand (with my basic understanding of things galvanic) how the paint and hull will be affected. Again - can one have too much zinc in the water?

I dont think you have actually told us what material your hull is made of.

If you are talking about antifouling paint on a GRP hull I'd think the answer is "no".

If you were considering fitting more anodes than MGDuff recommend on a painted steel hull then, "perhaps".

 

[coreng]

As lot of us seems to have a good understanding of marine corrosion, may be some could explain how too much zincs can cause over protection because MgDuff does not give any explanation about this (nor the others, to their discharge...). And as weight of zinc impacts lineary duration of protection...

 

[makingplansfor]

As lot of us seems to have a good understanding of marine corrosion, may be some could explain how too much zincs can cause over protection because MgDuff does not give any explanation about this (nor the others, to their discharge...). And as weight of zinc impacts lineary duration of protection...

You have now really confused me - it was you that suggested that I was "over protected" in the first place.......

Thanks MacS, I do indeed have a GRP hull so hoping that the clean up of the terminals does the trick - I'll find out in March 2012, unless of course all my paint falls off in the meantime!!

 

[Tintin]

www.galvatest.com - keeping corrosion under control...

From coreng signature - is this an attempt at SEO?

 

[coreng]

RedDragon, what does that mean?

Makingplansfor, don't be worried about that. The more advices you get, the better (or the worst, though...) you are...

Vics, can you please explain accurately where the problem is?

Thanks...

 

[VicS]

Vics,

I never attack first. You are making a mess about electro-negativity and you produce electro-negative values that are the same as the one published in white paper (OK for Calomel but you won't have one in your boat, either).

Furthermore, Magnesium, Aluminium and Zinc are top ranked in electro-negative potential.

So, what's the mess about?

No. Magnesium aluminium and zinc are all relatively electropositive They produce positive ions in solution.

(Electronegative elements such as the halogens produce negative ions in solution.)

You are confusing negative electrode potential with electronegativity

The more electropositive elements have the most negative electrode potentials.

Confusing I know.
It is therefore better to avoid the use of the terms electropositive and electronegative when discussing galvanic corrosion or other topics related to electrochemistry.
Reserve them for discussions about chemical bonds within molecules.

It is better to refer to magnesium, zinc etc simply as more anodic ( although even that can lead to confusion), having the most negative electrode potentials ( as you do in in the above quote) or even as least noble.

It is not me who is "making a mess about electronegativity" I can assure you.

 

[coreng]

Sorry then for the short-cut. It should read electro-negative potential metals instead of electro-negative metals...

Agree?

PS I don't know if you say this overthere but mind not throwing the baby with the bath water... A lot of boaters are usually not aware of corrosion (nor chemistry!) problems and providing a little understanding could help saving a few hulls, shafts and props...

 

[Tintin]

RedDragon, what does that mean?

SEO = Search Engine Optimisation, but I think you knew that.

Having read your posts which are:

- inaccurate, this view being based on the response from people like VicS who knows his onions,

- and from the responses you have written that are "stuffed" with potential anti-corrosion search terms,

- and looked at some of your previous posts which have the same,

- and taken into account your signature with the link to your website,

- and having looked at your website and seen the back link to YBW visible on the front page,

- and being familar with the techniques to get websites ranked higher,

my conclusion is that your posts and some of the threads you have started are a cynical attempt to leverage YBW to help your business get better search rankings.

Now I may be wrong, you may be all heart, but from what I have seen I "smell a rat".

BTW my posts has just helped you a little bit in your marketing, but I hope others will now realise that responding to your threads is helping your business, and I'm fairly certain that using the forum in this way is against the forum rules.

Webcraft may have a more expert view on this

 

[coreng]

OK, I din't.

1) YBW rules allows commercial signature
2) YBW rules asks for a reciprocal link (maybe for SEO, too ?)
3) Our papers are not inacurate. Corrosion is our job and we appear to know it. And you have no way to dismiss what we are saying except shouting loudler. This is really strange pratices (our contradictors arguments remains affirmative and don't solve the problem).
4) Electro negativity or positivity is a matter of conventional terms. We talk in terms of potential, chemists in terms of classification. And the main subject is boat corrosion, not chemists debate (I think...). Furthermore it was also a translation matter : french version speaks of potential
5) I answer posts where I might help. I shut up when I can't...
6) You are an intelligent man : you decide if info is valuable or not to you
7) I wonder in my posts why pleasure boats shafts, outdrives, props are always pitted. This does not happen in naval industry. Guess why so many problems occurs in pleasure world... (despite apparent huge amount of available specialists : surveyors, engineers, chemists, etc.)
8) I have have a question concerning corrosion, still unanswered yet (even if I have a slight idea) : why don't pleasure boaters use (simply available and efficient) technologies widely recognized and practiced in naval industry?

 

[Tintin]

3) Our papers are not inacurate. Corrosion is our job and we appear to know it. And you have no way to dismiss what we are saying except shouting loudler. This is really strange pratices (our contradictors arguments remains affirmative and don't solve the problem).

Errr, no-one is shouting as far as I can see. This thread has shown clearly, to all, that you don't know what you are talking about.

You have changed your mind about elctro-positive and negative when it has been pointed out to you by someone who does know. I'm not an expert in this subject but even I know that it a fundamental mistake.

The more you post the more a fool you make of yourself, and that can't be helping your business at all.

Here's a suggestion - leave the subject of your work out of the forum. Put it on the shelf when you come in here.

Honestly, your posts are not winning you business or helping your cause.

 

[coreng]

Why do you attack me? Needs exercise?

Do you know yourself what you are talking about when dismissing YBW link on our website when it is YBW itself who asks for it?

Of course, you're not shouting as everyone can read... Do you even know about what you are complaining at? You seem so authoritative, too... I then must guess you must be right. : next time, I will concentrate my talks on cookery... It's OK for me giving advices on all subjects where I don't know anything... Hope everybody does the same to keep forums useful...

Though problems remains largely unsolved...

 

[Tintin]

Don't tell him Pike

<shakes head sadly on>

http://www.youtube.com/watch?v=0V3SqxUomwk

<shakes head sadly off>

 

[coreng]

Crossing the T's and dotting the I's...

I don’t really understand why such agressive exchanges occurs on this forum.

I was only trying to help boaters with our knowledge of anti-corrosion and bring them best practices from naval industry. No less, no more…

Thus, answering a simple question as “barnacles on anodes” seems to set cross fires from everywhere, meanwhile main issue remains largely unsolved.

All information delivered reflects state of the art, adapted to non-professionnal readers. Ambiguous terminology electro-negative metals or, implicit electro-negative potential metals for example, should not, in a civilized society, support negative judgments such as the one expressed along this post without prior courteous and motivated exchanges theorically helping to clarify disputed facts.

As it does not seems to be the prevaling rules over here (i.e. RedDragoon...), I guess the future of all of us won’t be so friendly…

And this is a philosophical thought.

Have a good day gentlemen…

 

[makingplansfor]

Almost reluctant to restart this debate, however, my problem should be really simple for someone in the know to advise. Having cleaned and refitted the offending anode, some of the tests that I have done are confusing. Continuity through the hull studs and across the anode are good and from the studs to the engine. There is no continuity from the engine to the shaft as I expected - thinking this through however I am guessing that continuity would have to be through the internals of the gearbox........... oh dear.... as you can tell by now this is not my specialist subject.........

 

[VicS]

Almost reluctant to restart this debate, however, my problem should be really simple for someone in the know to advise. Having cleaned and refitted the offending anode, some of the tests that I have done are confusing. Continuity through the hull studs and across the anode are good and from the studs to the engine. There is no continuity from the engine to the shaft as I expected - thinking this through however I am guessing that continuity would have to be through the internals of the gearbox........... oh dear.... as you can tell by now this is not my specialist subject.........

genuinely no connection from engine to the gearbox output shaft?

You are not measuring to the other side of a flexible coupling .... they have to be bridged in order to complete the circuit.

Just oil films on all the gearbox components ?

You may have to use a brush system such as MG Duffs "Electroeliminator"