# What to do about anchor chain rust?



## Blewtooth (Nov 21, 2018)

I have BB chain that has been rusting a great deal lately. I don't think that the chain is anywhere near needing a replacement but now every time I put the anchor out the foredeck is full of little rust particles that get everywhere and leave stains if they are not washed off in time. 

I have seen one guy who was wire brushing his chain and painting it but I have fears that if I try this the paint might start flaking off all over the deck as well as new rust.

Is there anyway I can galvanized it again myself or would I have to go to some place where it might be really expensive to have it done?

Or will it be cheaper just to buy new chain?


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## Minnewaska (Feb 21, 2010)

It does sound like the galvanization has failed, which is all too common these days. Even finding a place to re-galvanize is hard, let alone probably not cost effective, especially if you have to ship it both ways. New chain time, it sounds. It is a wear item, unfortunately. 

If you have access to fresh water, keeping it well rinsed and dried after each use will extend it's life significantly. I hose the locker down every time I return to the slip.


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## chef2sail (Nov 27, 2007)

Sounds like the galvanization has lived its life. How old was it?
Do you have space for a wash down pump?
Are you in a slip and have fresh water available?
Longevity will be increased by a fresh water rinse


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## MikeOReilly (Apr 12, 2010)

Listening... I have the same problem right now. I've looked into getting the chain regalvanized, but even where it is possible, which isn't very easy, the cost is exorbitant. It's a shame because the chain has years of life left.

I've looked, rather superficially, at various DIY coatings. Am curious if anything like this would be worth it.


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## SanderO (Jul 12, 2007)

Wash the chain after use. If the chain is rusty at the end connected to the anchor... turn it end for end until the better end is too rusty... then replace.

Galvanizing old chain is costly, time consuming and the results are poor.


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## MikeOReilly (Apr 12, 2010)

SanderO said:


> Wash the chain after use. If the chain is rusty at the end connected to the anchor... turn it end for end until the better end is too rusty... then replace.
> 
> Galvanizing old chain is costly, time consuming and the results are poor.


It's just not an option for me much of the time. I spend sometimes months off the dock, anchoring all the way. I don't have the fresh water to spare on board. If it rains I collect, and can use that, but this is hit-and-miss.


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## Whalerus (Apr 24, 2019)

Try connecting both ends of the chain to the back of a car or bike forming a loop. Then drive on a gravel road till the rust is all gone.


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## capta (Jun 27, 2011)

We've had to replace our chain about every 2.5 years as we sit on it almost every night of the year.

Is your chain jumping in the gypsy? Regalvanizing could be an option if you can find someone who can do it and will put an extra heavy layer of zinc on to make up for the loss from rust.

But you must find a place that does _hot dip _galvanizing, not electroplate, which is actually what new chain comes with, no matter what the advertising says. Hot dip comes out very rough and dull, not smooth and shiny like the chain sold today.
Cleaning the chain and galvanizing it are very environmentally unfriendly, so it was pretty much not done any longer in the US, but with this administration, who knows?


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## colemj (Jul 10, 2003)

Whalerus said:


> Try connecting both ends of the chain to the back of a car or bike forming a loop. Then drive on a gravel road till the rust is all gone.


While this might get rid of the rust, it will do nothing to stop the rust from reforming almost immediately. Definitely in the time of a single use again, or just sitting in the locker for a few days.

Regalvanizing chain is almost never the best approach, particularly for boats that use a windlass. While the galvanizing may be thick enough to accommodate the lost steel, the chain remains weakened, and the cost is a large part of just buying new.

We have found that by the time chain has rusted to the point of flaking, it is a short matter of time before one goes to deploy it and finds it kinked and rusted together so bad it won't come out of the locker.

In the scheme of things, good chain is relatively inexpensive. We get 5-7yrs out of Maggi chain in full time cruising, and the last 300' of 5/16" G43 we bought cost $700. So about $100-$150/yr. Just don't buy chain at West Marine if cost is a concern.

Mark


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## contrarian (Sep 14, 2011)

If you get the rust off you can use ZRC cold galvanizing high zinc compound. May be able to get another season or 2 out of the chain depending on how good of a job you do and how often you anchor. I have to admit I do like the idea that Whalerus proposed for getting the rust off. If you have ever had a rusty chain come loose and drag down an asphalt road you'll know how effective it is for removing rust. Of course it removes more than just rust which could be a problem. Don't have any gravel roads in my neck of the woods ( we have pig trails and two rut roads) and not many of them left anymore but if we did have them I would certainly give the idea a shot.


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## RegisteredUser (Aug 16, 2010)

In a barrel with sand and some water
Roll barrel around


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## travlin-easy (Dec 24, 2010)

I washed down my chain after every use, it was 1/4-inch BB and never had a speck of rust in more than 10 years of use. The previous owner had 3/8 BB chain, washed it down after every use and it was still clean 25 years later. I think the crud and mud left on the chain may have more to do with the loss of galvanize. I have used galvanic sprays, and they tend not to hold up for very long, but it would sure be a lot less expensive than buying new chain.

Good luck,

Gary


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## MikeOReilly (Apr 12, 2010)

travlin-easy said:


> I washed down my chain after every use, it was 1/4-inch BB and never had a speck of rust in more than 10 years of use. The previous owner had 3/8 BB chain, washed it down after every use and it was still clean 25 years later. I think the crud and mud left on the chain may have more to do with the loss of galvanize. I have used galvanic sprays, and they tend not to hold up for very long, but it would sure be a lot less expensive than buying new chain.
> 
> Good luck,
> 
> Gary


Galvanic sprays! That's what I was wondering about Gary. Can you tell me more? I know nothing about all this stuff. What type, or product name? And how hard is it to apply?

I know new chain is in my near future, but I check my chain pretty thoroughly and I believe it has plenty of thickness left. It's just getting a lot of surface dusty rust. I'd like to get another season or two out of it if I can.


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## RegisteredUser (Aug 16, 2010)

Rustoleum cold galv spray


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## chall03 (Oct 14, 2002)

We are at a similar point. 

The right answer sadly I think is always going to be new chain. 

But would be interested in how you go trying some of the above measures.


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## colemj (Jul 10, 2003)

We've used galvanizing sprays, and they _might_ get you another season, but not much more. They are just paint on an imperfect and unprepped surface subject to abrasive use, so it comes off pretty quickly, particularly if anchoring in sand or similar substrates.

To have any hope of it sticking on chain, the existing rust has to be removed, and the chain cleaned. Removing rust by dragging it on a gravel road is likely to remove enough mass to make the chain no longer fit the gypsy.

If one only has 30' or so of chain, then maybe this is a reasonable approach, although 30' of new chain is not an onerous expense. If one has 300' of chain, by the time you haul it off the boat, take it to a gravel road and drag it around, then buy 20 cans of galvanizing spray and spend an entire day coating the chain, you have spent a lot of time and a good chunk of money that would have been more fruitful applied toward new chain.

Galvanizing spray works better for something like the anchor, where the tip often starts to rust. Wire brush that clean, treat with rust lock, and spray on galvanizing. This does work because the anchor tip sees little abrasion beyond each initial set, takes very little time, and costs only a can of spray.

Mark


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## Minnewaska (Feb 21, 2010)

I've used cold galvanizing, in fact, I plan to paint the new keel studs and nuts in the bilge with it to protect them. It works reasonably well on stationary metal you want to protect. I'm highly skeptical that it would take much abrasion to remove it. I'm sure it would last a little while and probably matters greatly whether the chain was laying in sand or soft mud. Perhaps whether the water was brackish or high salinity.


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## outbound (Dec 3, 2012)

Have found for anchor tip.
Wire brush until bare metal.
Good zinc rich primer.
Over coat with metal paint. The over coat is quite a bit harder than zinc paint so lasts longer.

Down here just use spray cans. From hardware store. Most places have primer for cars and metal paint of some sort for engines, stoves and the like. Way cheaper than IWW or budget.

Think many types of stainless aren’t as strong as simple mild steel. Stainless chain is quite expensive. See it used for dinghies as now cable isn’t sufficient to deter thieves any longer. We went with galvie. I can replace it four times for the cost of stainless. 

Periodically will pour straight vinegar into chain locker and flush with fresh. Keeps it clean and smelling nice. Anchoring mostly in sand and dip anchor up/down so it’s clean while leaving. Chain is 7 years old and still good. Biggest deal is to not get Chinese chain if you can avoid it. Recently have been putting out the same amount of chain over and over (100’). So getting grass growth from 90’ to 100’. Use stiff nylon brush to remove. Trick is to do it right away. If it dries it’s hard to get off.


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## Don L (Aug 8, 2008)

Given the importance, use, life span, cost of anchor chain when it gets to the too rusty period the only real answer is to ................... replace it.

To me it just just crazy to do things like painting etc. that it the end put your boat at risk ti save the cost of a chain every 5 years or so.


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## hpeer (May 14, 2005)

Pondering the same question. 4 year old chain. It spends perhaps 150 night on anchor per season so 600 nights. Starting to see some rust. If I flip it the whole l get maybe another 3 years. So maybe 1,000 nights on anchor. That’s a 2-3 bucks a night to anchor. 

3/8” g4.


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## ottos (Aug 12, 2008)

Anyone have experience with these folks? Hot Dip Galvanizing- Valmont Coatings


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## olson34 (Oct 13, 2000)

It's been a few years, and it's true that pollution rules have reduced the number of companies, but galvanizing is still possible.
When I had two shorter lengths of chain and two rusty anchors, I took them to a local (well, out in a suburban industrial area) galvanizer. They have a sand blasting company next door.
Total bill for cleaning and dipping was quite a bit less than replacing all of our ground tackle with similar quality.

It is a heavy enough box of material that you probably need to find a way to transport it and pick it up. 
They had our anchors and chains ready in a few days, shinning like new, on a pallet.

BTW, I had previously tried using the spray can of "cold galvanize" and it rubbed of pretty fast in use. Perhaps my application technique was not up to standard... ??

Pix here:
https://ericsonyachts.org/ie/threads/re-galvanizing-anchors.3951/
And no, the shine is long gone, but no rust has returned!


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## hpeer (May 14, 2005)

A few years ago I tried pretty hard to get some chain galvanized in the Philadelphia area. I ended up in North Jersey, dropped the chain off, and the hey kept it for a month only to eventually tell me they could not do it. 

Ended up buying new chain.


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## hpeer (May 14, 2005)

ottos said:


> Anyone have experience with these folks? Hot Dip Galvanizing- Valmont Coatings


I've not used them but I know of Valmont as they make metal, galvanized, light poles. Like you would see on a street.

Been around a long time, well respected company.


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## bigdogandy (Jun 21, 2008)

I've had decent results using Ospho to treat mild rust on anchor chain before spraying hardware store cold galvanizing on it. It helps give the paint a better surface to bond to. Once the chain gets rusty it's still a maintenance issue, though - the spray on galvanizing isn't nearly as tough as the hot-dip, and if you use the chain a lot you're probably not going to be able to re-coat it enough to stay ahead of the rust. For folks who use their chain seasonally, though, doing the ospho / spray galv process at the end of the season can be a good way to extend the life of the chain. YMMV


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## wsmurdoch (Jan 23, 2007)

I have had my Acco chain re-galvanized by Bristol Galvanizing (now AZZ) in Bristol. VA and by South Atlantic Galvanizing in Graham, NC, twice each. It was cheaper than buying new. My biggest problem was getting enough weight together to reach their minimum charge weight. I collected chain and anchors from friends to get up to around 300 lb. The last time I asked, neither were doing chain. Both had too much business to mess with high labor, low volume work. It is after all a little hard to galvanize chain without soldering it into a big lump. They'd rather do structural steel. Faced with that problem I bought a 550 ft drum of Titan 5/16" BBB from Amazon at a price much less that WM ($1313 vs $3100). It was a Prime item so shipment was free. Delivery put it in my garage. I cut 137 ft from the 550 ft drum and it is now on the boat. It should last three years before it starts to stain the deck. Then I will cut off another 137 ft. In the end I'll have about 600 lb to be re-galvanized. Maybe I'll still be alive. Maybe the galvanizing companies will then want the business.

Keep an eye on Titan chain on Amazon. I think they dispose of damaged stock via this route. The stuff comes and goes. It is Chinese chain, but they also made my Ronca anchor and my zinc anodes, so I'm not too worried. Hey, the Chinese also made my cell phone.

Bill


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## RegisteredUser (Aug 16, 2010)

Iirc, many years ago i was told a 300# minimun from a company in jax.
Sounds similar, but i never did it at that time


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## Waltthesalt (Sep 22, 2009)

I've had small batch galvanizing done here in Seattle but the places don't like to do it as they do large pieces. Used chain at a consignment shop however is usually pretty cheap.


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## skipgundlach (Oct 4, 2002)

Whalerus said:


> Try connecting both ends of the chain to the back of a car or bike forming a loop. Then drive on a gravel road till the rust is all gone.


That's great prep for re-galvanizing (but putting one end on the car, driving some ways, and then putting the OTHER end on will make sure it all gets exposed to the abrasion), but merely exposes the raw metal to better rust in salt water otherwise.

It also presumes a car and some sort of hitch :grin


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## SanderO (Jul 12, 2007)

Owning a boat means keeping it, the components and systems in good repair. This includes replacement and upgrades as well.

Galvanized chain and anchors will corrode. They do continue to perform as needed with unsightly corrosion. But too much corrosion will weaken any metal component and it then fail under normal conditions. I suppose some rusted chain does part. I haven't read accounts of it getting that far.

Bite the bullet and replace the chain and anchor before it degrades too much.

These sorts of expenses are part of boat ownership.


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## colemj (Jul 10, 2003)

skipgundlach said:


> It also presumes a car and some sort of hitch :grin


It also presumes an available dirt road, and understanding law officers/homeowners around it...

Mark


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## SanderO (Jul 12, 2007)

colemj said:


> It also presumes an available dirt road, and understanding law officers/homeowners around it...
> 
> Mark


It's a dumb idea and could endanger other people using the road.


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## MikeOReilly (Apr 12, 2010)

SanderO said:


> It's a dumb idea and could endanger other people using the road.


Hmmm, I wonder if you have to fly a big red flag off the end of the chain, like with loads that hang off the back?

Needless to say, I've never done this. But I have anchored in shallow, gravelly places and basically let out all my chain. A bit of dragging around cleans the rust off pretty good. The chain comes up nice and clean.

Unfortunately, it returns pretty quickly


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## colemj (Jul 10, 2003)

We've anchored in some places with stinky mud where after a few days, the rusty chain laying in the mud came back up rust free and black like it had been treated with rust treatment. Stayed rust free for a considerable time afterward. 

Probably was a type of rust treatment - an anaerobic environment that replaces the oxide with something else common to that environment (sulfate? tannate?).

Mark


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## MikeOReilly (Apr 12, 2010)

colemj said:


> We've anchored in some places with stinky mud where after a few days, the rusty chain laying in the mud came back up rust free and black like it had been treated with rust treatment. Stayed rust free for a considerable time afterward.
> 
> Probably was a type of rust treatment - an anaerobic environment that replaces the oxide with something else common to that environment (sulfate? tannate?).
> 
> Mark


Hmmm, now that you mention that, I had the same thing happen to me two seasons ago. We were anchored in a harbour for a long time with a bottom that was this fine, black, sticky mud. Probably a combination of mud, loon-crap, and generations of fishing activity.

The chain came up clean of rust, but stained very dark. It stayed clean for a while after that. I hadn't really thought about it, but you're probably right about some other chemical reaction taking the location of the iron oxide. Interesting...


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## bigdogandy (Jun 21, 2008)

High phosphate content in the mud could be acting to convert the iron oxide rust on the surface of the chain to iron phosphate? That could explain the black discoloration....


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## Minnewaska (Feb 21, 2010)

I wonder if bare metal or rusted metal corrodes faster. Could a coat of rust, marginally protect the surfaces below from further oxidation? Better to have a solid protective coating, but I wonder which of the above is better.


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## colemj (Jul 10, 2003)

I don't see how it makes a difference even if rusted metal slowed corrosion. Under that scenario, bare metal would rapidly rust, then slow down, while rusted metal would already be slow. Within a few days, they would be in the same state.

My experience is rust doesn't seem to slow down as it advances. As it gets bad, it flakes off exposing underlying metal.

Mark


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## MikeOReilly (Apr 12, 2010)

colemj said:


> I don't see how it makes a difference even if rusted metal slowed corrosion. Under that scenario, bare metal would rapidly rust, then slow down, while rusted metal would already be slow. Within a few days, they would be in the same state.
> 
> My experience is rust doesn't seem to slow down as it advances. As it gets bad, it flakes off exposing underlying metal.
> 
> Mark


(forgive me if this is patently obvious...)

Since it's an oxidation reaction, a coating of the oxide (rust) can inhibit further oxidation of the base metal by acting as a physical barrier. This is why copper roofs, and indeed bronze fitting, are left in their green state.

The problem with iron oxide is that it's not physically stable, i.e. it flakes. And since chain is constantly moving, it further tends to dislodge the oxide, exposing more of the underlying metal to further corrosion.


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## Capt Len (Oct 9, 2011)

A quick search of internet simply answers the cause of rusty chain A quick observation of the offered information should clear up any misunderstanding of what appears to be a simple problem. ............... There is mounting indirect evidence pointing to a sulfur-fueled iron cycle not only within marine sediments (Koretsky et al., 2003; Holmkvist et al., 2011) but also terrestrial systems that span acidic to alkaline conditions (Akob et al., 2008; Komlos et al., 2008; Pester et al., 2012; Osorio et al., 2013; Flynn et al., 2014; Kwon et al., 2014). Previous models of geochemical zonation have likely overlooked the importance of this cryptic cycling by relying primarily on measurements of substrate and endproduct concentrations. In particular, a rapidly spinning cycle involving the consumption of sulfide via reaction with iron oxides and microbial respiration of the subsequent sulfur products (sulfate, sulfur, thiosulfate) leads to low sulfate and aqueous sulfide levels but high Fe(II) conditions that would suggest ferric iron respiration and not sulfur metabolism. By measuring production and consumption rates of metabolic substrates and products, detecting the oftentimes elusive intermediates and monitoring active metabolic pathways, the relevance of these cryptic cycles, involving various elements, within environmental systems will continue to emerge.

Observations of sulfate reduction and cryptic sulfur cycling in natural systems have frequently been attributed to the presence of more crystalline iron oxides that were presumed to be biologically unavailable. Our conservative estimates here indicate that along the upgradient portions of the column where both sulfate and ferrihydrite were available, reaction of ferrihydrite and biogenic sulfide accounted for nearly 40% of the observed iron reduction, with an additional 30% if sulfur recycling is invoked. Thus, this research shows that within natural sediments incubated under conditions mimicking natural systems, sulfur-fueled iron reduction is a dominant process regardless of the iron oxide present, including the most bioavailable iron oxide two-line ferrihydrite, and despite low-sulfate levels. In fact, even after 19 days of incubation, more than half of the added ferrihydrite was still present, indicating that observations of sulfate reduction within natural sediments do not necessarily preclude the presence of poorly crystalline and microbially available iron oxide phases.

This respiratory sequence, where sulfate reduction precedes or occurs simultaneously with ferrihydrite reduction, leads to an inverse redox zonation that is in stark contrast to long-standing thermodynamic models (Chapelle and Lovley, 1992). Thus, regardless of the mechanistic underpinning, a thermodynamic-based hierarchy cannot alone predict operative respiratory pathways and geochemical zonation in nature. One complicating factor is the frequent utilization of bulk aqueous chemical conditions in thermodynamic models, which most likely do not accurately reflect the biogeochemistry of sedimentary microenvironments. Micro-scale heterogeneity will no doubt hinder our ability to accurately calculate true in situ reaction energetics. It cannot be ruled out therefore that micro-scale porewater heterogeneity leads to localized conditions that favor metabolic reactions not predicted by bulk geochemistry.

By relaxing the presumed energy-based hierarchy between iron- and sulfate-reducing communities, reinterpretation of environmental geochemical zonation will undoubtedly bring to light an overlooked control of kinetic, physiological and ecological factors in the cycling of iron and sulfur. Indeed, the dominance of a microbial Fe cycle has been long assumed for Earth’s earliest records (Canfield, 2005), both before and after the initial rise of atmospheric oxygen. This was always taken to reflect an excess of iron over other, more oxygen-dependent, electron acceptors like sulfate. The results presented here, however, indicate that even micromolar levels of Archean sulfate (Halevy, 2013) could catalyze large-scale iron cycling—no longer then can evidence for active iron cycling be viewed independent of the sulfur cycle. These findings also challenge certain biogeochemical models predicated on the classic redox tower, perhaps helping to explain the persistence of a prominent Fe redox cycle throughout the Proterozoic (Planavsky et al., 2011) in the face of higher pO2, rather than requiring an excess of ferric iron or paucity of organic carbon or sulfate (Johnston et al., 2010). As ferrihydrite is a dominant product of iron oxidation in the rhizosphere of terrestrial and wetland plants (Emerson et al., 1999; Hansel et al., 2001), this Fe oxide-based sulfur recycling could also explain unexpectedly high rates of sulfate reduction within low-sulfate wetland sediments (see Pester et al. (2012))—systems that single-handedly account for up to 40% of global emissions of methane (Wuebbles and Hayhoe, 2002). That noted, given this updated understanding of the nature of this system, direct tests should follow. What is clear is that sulfur recycling is an essential catalytic engine driving the Fe cycle. ,,, So there you have it.


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## bigdogandy (Jun 21, 2008)

Awesome - the unexpectedly high rates of sulfate reduction within low-sulfate wetland sediments has been bugging me for a while now, and now I have a much better understanding of why that has been occurring. 

Thanks!


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## MikeOReilly (Apr 12, 2010)

My brain hurts.


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## Minnewaska (Feb 21, 2010)

I’ve had a couple of cocktails and felt like I was reading Charlie Brown’s teacher. This coming from someone who watches numberphile and physics YouTube channels.


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## colemj (Jul 10, 2003)

Those studies appear to speak toward microbial ecology, and not straight chemistry. While it is possible that the chain/rust is establishing microbial cultures, and they are metabolizing off it, it is more likely that straightforward chemistry is occurring. 

Sulfate isn't the only possible reactant. Phosphate and tannate from tannic acid are possibilities, and I'm sure there are other organic acids with correct oxidation/reduction states.

Iron sulfate is yellow and soluble in water, and the more common form is ferrous sulfate, and not ferric sulfate, so that would require not only a displacement reaction, but a redox one as well. I'm too lazy to look up the activation energy of the iron sulfate reactions to see if they are exo or endothermic. If the later, it probably isn't going to happen lying in the mud. 

If I had to WAG, it would be iron tannate from tannic acid, since this could be expected in high concentrations in muck.

Mark


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