Talk:Galvanic corrosion

Move requested

The following discussion is closed. Please do not modify it. Subsequent comments should be made in a new section.

I have requested a move of Galvonic corrosion to Galvanic corrosion to fix the spelling error. An admin will take care of it. Dicklyon 01:36, 26 February 2007 (UTC)

Why trouble an admin with trivia when you can do it yourself? Done. --Wtshymanski 03:55, 26 February 2007 (UTC)

The move instructions are very clear about this; read them; undone. Dicklyon 04:01, 26 February 2007 (UTC)

Page moved, per request. Cheers. -GTBacchus^(talk) 09:49, 26 February 2007 (UTC)

The discussion above is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.

Merge Lasagna cell here?

The following discussion is closed. Please do not modify it. Subsequent comments should be made in a new section.

I proposed that we merge lasagna cell into this article, since it's a good example of galvanic corrosion and not something so notable as to need its own article. Please support or oppose here:

• Support naturally, since I proposed it. Dicklyon 21:13, 26 February 2007 (UTC)
• Support The page in question is extremely short. Its top paragraph nicely fits with the silver cleaning example in the opening section, maybe even in a new common examples section. Careless use of the term battery should be avoided though. Waerloeg 08:14, 27 February 2007 (UTC)

Done. Dicklyon 06:49, 3 March 2007 (UTC)

The discussion above is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.

Chemistry

Could someone who knows add some information as to the meaning of corrosion. Is it simply oxidation , salt formation , both or neither?

I came to this page for specific information on G.C. and part none the wiser.

thx. —Preceding unsigned comment added by 77.216.201.48 (talk • contribs)

I think it's generally oxidation, but not necessarily with oxygen. In a salt solution, choride ions are the oxidizing agent, so you get a metal cloride. So, yes, it's salt formation, too. Dicklyon 20:41, 28 April 2007 (UTC)

Hey no, chloride ions are not oxidizing agents. Chlorine is though. Salts can form when oxygen, a very common oxidizing agent, reacts with metals to form metal oxides. Metal oxides react with chlorides to make metal chlorides. This is in normal corrosion. Please do not spread untrue chemistry facts. --Chemicalinterest (talk) 00:07, 8 September 2010 (UTC)

Galvanic Corrosion in Water Cooling?

Does anybody feel confident to make a blurb about galvanic corrosion in water cooled PCs? If aluminium and copper pads are used in the same loop then galvanic corrosion will occure. To deal with this problem water coolers choose to mix the water with some anti corrosion agents. —Preceding unsigned comment added by 83.113.208.118 (talk) 16:05, 9 July 2008 (UTC)

Lasagna Cell and Aluminium poisoning

I wonder if we might add a sentence to the Lasagna Cell paragraph about the dangers (or lack thereof) of Al(III) poisoning. It seems relevant... Gaedheal (talk) 21:29, 17 November 2008 (UTC)

Aluminum(III) poisoning is not much more toxic than other metals, such as rubidium. It might make a horrible metal taste, though. --Chemicalinterest (talk) 00:08, 8 September 2010 (UTC)

Examples & Lasagne cell

I'd like to add 'Lasagna cell' to 'Examples' and move the section to the end of the article, so the definitions and technical stuff comes first. Anyone have any comments or objections? Apau98 (talk) 05:24, 20 January 2011 (UTC)

Sounds good to me. Wizard191 (talk) 18:21, 20 January 2011 (UTC)

Other galvanic corrosion conditions ?

The intro paragraph of this article reads as if galvanic corrosion occurs ONLY when IMMERSED in an electrolyte bath:

Galvanic corrosion is an electrochemical process in which one metal corrodes preferentially to another when both metals are in electrical contact and immersed in an electrolyte. [emphasis added]

but I have recently been investigating metal roofing systems and there are frequent mentions of "galvanic corrosion" due to incompatible/dissimilar metals in contact (such as copper roofing sheets attached with common roofing nails made of steel). A good webpage on this topic is here. MY QUESTION IS: Is the corrosion of metals due to dissimilar galvanic scale without electrolyte immersion also "galvanic corrosion"? or if not then what is the correct term for this condition ? Or is the intro paragraph using the wrong terminology? 75.80.20.99 (talk) 01:51, 13 September 2011 (UTC)

You're right to point this out. For example, galvanic corrosion is blamed for the failure of ceiling light fixtures in the Big Dig tunnel. Although underground, the fixtures are certainly never immersed in water, but they corroded badly anyway. I've fixed the lede. Reify-tech (talk) 05:13, 23 February 2014 (UTC)

I am at a loss

I am a retired Industrial Engineer, and also a Wikipedist. To honor my retirement, I seldom participate on technical articles, but from time to time I happen to fall in one, like now, for search of information. I try to find out if two metals will be compatible, to work in normal outdoor atmosphere. There is a good information given in the section "Galvanic compatibility", in which some values of acceptable "Anodic Index" are given for different situations. The problem is this Index is not defined. There is also a table of "Anodic Indexes". Is there any relation between them and the Standard electrode potentials? Seeing the numerical values, it does not seem so. Of course, I am acting now as a Wikipedist, and if I can I will also help to improve clarity.--Auró (talk) 21:16, 16 December 2011 (UTC)

I have made some progress, as reflected in the "Galvanic compatibility" section. It still remains to be find the relationship between "Anodic Index" and "Standard electrode potential". I also would like to have the "Anodic Index" table checked.--Auró (talk) 10:02, 17 December 2011 (UTC)

Typical equations

The Overview section is vague and addresses a number of separate concerns without separate headings: what it is; how it is combatted; what can go wrong when it is combatted. The first of these should include a diagram and the chemical equations for a typical case. — Preceding unsigned comment added by 125.253.44.20 (talk) 02:55, 26 July 2013 (UTC)

USS Thresher

The following section may be controversial, and needs WP:RS before it is reinstated:

Galvanic corrosion is of major interest to the marine and shipbuilding industries. Galvanic series tables for seawater are often consulted due to the extensive use of metal In shipbuilding. As an example of its importance, it is possible that corrosion of silver brazing In a salt water pipe caused a failure that led to the [[USS Thresher (SSN⁻593)|USS Thresher]] sinking with all men lost.

The USS Thresher sinking was caused by pipes NOT brazed during construction. The ultrasonic testing process back then could not show a joint that was prepped and not yet brazed. The FOIA has released the findings and they agree with my father-in-law who was on the team that investigated the loss of Thresher.

I did not write the above, but moved it here from the article. Please discuss it here, not in the article. Reify-tech (talk) 20:23, 11 February 2014 (UTC)

Not Exclusively Between Dissimilar Metals

The lede paragraph is misleading. It suggests that galvanic corrosion only occurs when two types of metal are in contact. It is my understanding that galvanic corrosion can occur when any two conductors are in contact, even if one is not a metal. A good example of this is the galvanic corrosion that occurs when carbon fiber (an excellent conductor) is bonded to aluminum in boats and bicycles. Not being an expert on the subject, I wanted to post my thoughts here before changing the article. Could a subject matter expert check my understanding to make sure I am correct? Thanks. Ebikeguy (talk) 20:57, 22 February 2014 (UTC)

Agreed. Since the issue is so common with carbon fiber, and use of carbon fiber is growing, the addition would be valuable. 73.60.233.220 (talk) 19:03, 22 January 2023 (UTC)

see 2021 article from Corrosion Communications: "Galvanic activity of carbon fiber reinforced polymers and electrochemical behavior of carbon fiber"[1] 73.60.233.220 (talk) 19:14, 22 January 2023 (UTC)

see existing mention of galvanic corrosion in Carbon fibers. (I've linked the Galvanic corrosion wikipedia page to that mention). 73.60.233.220 (talk) 19:39, 22 January 2023 (UTC)

The description on the Carbon fibers page should also be improved: the text does not clarify that galvanic corrosion is still a risk when carbon fiber comes in contact with metals. 73.60.233.220 (talk) 19:47, 22 January 2023 (UTC)

More than two metals?

...when two or more come into contact in an electrolyte, one metal acts as anode and the other as cathode.

This sentence is a bit confusing as it introduces the "or more" but only provides information on what happens to two. Are subsequent metals inert in this circumstance? — Preceding unsigned comment added by 207.195.36.138 (talk) 21:44, 4 December 2015 (UTC)

• • • Confusing or not, it is true. For example, you get three conducting materials with different potential electically connected and in contract with electrolyte whenever you add a sacrificial anode to a combination of two different metals.

If you had initially three materials and add a sacrificial anode, you get four materials - and so on. If intended sacrificial asnode gets dissolved (or looses connection etc.) the next material by electorcemical potential will start getting dissolved, functuioning as unintended sacrificial anode (which is galvanic corrosion).

Maybe so it could be told better - to be more easily understood by newbies - but in is exactly true, and also short (not like my writing).

Marjan Tomki — Preceding unsigned comment added by 193.35.111.55 (talk) 21:02, 3 August 2017 (UTC)

Diodes?

two semiconductor diodes in series. That doesn't make sense to me for AC as it would block either one or both cycles, shouldn't that be two diodes in opposite directions in parallel? — Preceding unsigned comment added by 106.69.35.237 (talk) 10:00, 14 March 2016 (UTC)

Anodic Index

The Anodic Index tables appear to be indicating negative voltages relative to gold. I believe that they should be positive voltages relative to gold. — Preceding unsigned comment added by Drsinmiasma (talk • contribs) 18:15, 23 October 2016 (UTC)

The source for this table does not include a table of Anodic Indices, although page 343 does include a table ranking metals from Cathodic to Anodic. — Preceding unsigned comment added by Garpiked (talk • contribs) 17:40, 13 September 2017 (UTC)

Electrochemistry!

Please add a few examples of the electrochemical reactions, like zinc in contact with iron is saltwater = XXX volts. Really conspicuously mising; can't find anywhere. 71.139.161.30 (talk) 20:15, 3 December 2016 (UTC)

NEC Requirements for Corrosion Protection

Why is there nothing with the National Electrical Code? — Preceding unsigned comment added by 98.95.16.51 (talk) 20:43, 29 July 2017 (UTC)

Because nobody has added it. You're welcome to add it, with references to WP:RS. Reify-tech (talk) 22:34, 29 July 2017 (UTC)

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