Regalvanization of anchor chain

[wsmurdoch]

Originally Posted by Mike Banks

You left out one really important thing. If your winch has the negative rail permanently connected to your battery system instead of using a double-pole relay connected to the foot switch on the deck, then your chain becomes a sacrificial anode and the galvanising lasts only a year or two instead of ten years. That is for GOOD galvanising. Cheap chain will probably last even less time.

How does electricity pass from the negative wire to the negative terminal on the motor, to the chain? How do the electrons return back to the battery positive terminal? Can you describe the circuit?

[wsmurdoch]

It just occurred to me that you might be worried about galvanic corrosion between the zinc on the anchor chain and the underwater bronze on the boat rather than electrolytic corrosion. I just measured the resistance between the negative to my winch motor and the winch drum. After scraping the surfaces of the black wire connection and the winch drum and after bumping the motor a few times, the lowest resistance of dozens I measured was 821,000 ohms. More usual was O.L. Between a scraped link on the chain and the black wire was always O.L.

[Markhunter1097]

Not really answered your question as I’m in Australia, but I was going through the same thoughts of getting anchor and chain re galvanised. Decided on just anchor as the chain expense was too much, anchor was $350 whereas the chain was over $1000. So was worthwhile doing the anchor but leaving the chain

[Markhunter1097]

Oh and let me add as a surprise, on the invoice they say not to put in salt water for 28 days!

[Underdog]

Originally Posted by Simi 60

Re galvanising high test chain will bring it back to standard chain strength but regalvanising standard chain does not affect its strength.

The acids used to clean the chain apparently also has an affect on high test chain causing hydrogen embrittlement.

I regalvanised a high tensile chain (before I found out about this) and so had a section tested. It rated at 7800kg, this was 10mm chain, where standard was between 1/2 and 1/3 that load rating.
I have heard of people boiling chain in linseed oil to fend off rust. Not done it myself but it would be a fairly cheap fix if you are going to end-for-end the chain and stop a rusting mess sitting in the bottom of your chain locker.

[Good To Go]

My vote is for re-galvanizing, just find a business that does a good job. Here in Queensland Au there is a company in Bundaberg that does a great job. I have used them 4 times over the years to do my anchor chains. Returns like new. They also do all the drumline chains for the Qld Government Shark Control Program.

[Mike Banks]

The negative terminal on the windlass is not usually insulated from the windlass chassis--so the gypsy and chain are also connected. Because the negative of the battery is also connected, usually through a radio earth, or in some cases the negative is connected also to the engine block you have a zinc chain connected to a copper radio earth and the propeller. That will give you electrolytic corrosion when at anchor, but if you have a wet anchor locker with a seawater drain, and you use shore power, your vessel becomes a better earth for any phase imbalance or fault on the power system, than the metal rods driven into ground of much less electrical conductivity than sea water.

Which is why one should always use an isolation system to disconnect your vessel's AC power from the grid power, and never run a shore power earth to your vessel.

If your vessel lies at anchor, that alone will provide enough corrosion to strip light galvanising. I used to work on lead cables in the days when they were common, and one milliamp of current over one year would dissolve one pound of lead. It would probably remove even more zinc or aluminium. For metal boats it is even more important to have mains power run through an isolating device, because stray current electrolysis is more severe than galvanic action, because the currents are usually greater, and will even corrode steel once it has removed any other more susceptible metals..

[mdenize]

Originally Posted by SaltyMetals

As i mentioned in my previous post (#22) you hv to find a galvanizer with a spin-galv unit. There maybe many galv plants who are hungry for business and will accept to galv yr chain even if they hv no spin-galv unit. It is easy enough to check beforehand and IMHO i wld not hv my chain re-galv'd at a galvanizer who did not hv a spin-galv unit. It is exactly for the same reason that nuts and bolts are ONLY galvanized at a plant w a spin-galv unit.

If you (and yr chain) does get stuck then i like the idea of using a propane torch since this way you would not lose any of the protective Zn. If you hammer the links or rely on yr windlass to do the job you would most likely lose flakes of Zn.
Andrew
"Genial Bee"

Awesome suggestion

I do alot of welding and when I want to protect the weld like a weld on galv pipe I just wipe the hot weld with pure zinc sticks then wire brush the weld... just like new. If the weld is too cold I just warm it up a bit with the oxy lpg torch which also smooths the final finish to as good as the hot dip galv plant.

I cannot think of any good reason to use a hammer to pull apart chain links that are welded together with zinc when a little heat and a wire brush would do that job sooo much better.

It is much easier to do when both the parent metal and zinc are new so do it straight away.

[southseasailor2]

I have had my chain re-galvanised in New Zealand at a facility that galvanises new steel work. Good results, heavy coating that lasts well. Much less cost than new chain

[Jim Cate]

Originally Posted by Markhunter1097

Not really answered your question as I’m in Australia, but I was going through the same thoughts of getting anchor and chain re galvanised. Decided on just anchor as the chain expense was too much, anchor was $350 whereas the chain was over $1000. So was worthwhile doing the anchor but leaving the chain

Mark, which vendor was that with?

Jim

[Simi 60]

Originally Posted by Good To Go

My vote is for re-galvanizing, just find a business that does a good job. Here in Queensland Au there is a company in Bundaberg that does a great job. I have used them 4 times over the years to do my anchor chains. Returns like new. They also do all the drumline chains for the Qld Government Shark Control Program.

Kenco @ around $1:68/kg.

Need to get our PWB chain done as we'll as our Manson supreme.
Hopefully the PWB will come back with better coating than original - .it was failing after a couple of months from new.

[GadgetGeek]

DockDoc - I see you are in NoVa and this place in Richmond, VA did anchor chain galvanizing for my friend's boat. The name has changed in the past few years from Virginia Galvanizing Corporation but this is the new website:

South Atlantic LLC | Service Galvanizing, Galvanized Steel Rebar, Masonry Products, Grounding Products Made in the USA

[captchetco]

I am still using appx 90' of ACCO G-4 that was on the boat when I bought it in 1983. It started out as 350' uncut. Over the years, I have replaced in 100' sections, and now only have 290' backed up by 100' of 7/8 Nylon 3S. The replaced chain has been replaced more than once. This year, I gave away 100' of Chinese galvanized chain that was only 2 years old, but had so much rust it was dangerous. Message? Buy the best chain. It lasts many years, and is worth the cost.
I have not regalvanized, but on several occasions a few years apart, I have put a gallon at a time of OSPHO in a bucket, and immersed the chain in it for an hour or so in sections. It stops rust for a season, at a cost of about $50. If you can fresh water rinse after each use, it helps also. Cheap Chain is not worth the money.
I also use 7/16 Crosby shackles to connect sections of my 3/8" chain.You can get them rated at 3X the standard ones for only a few bucks more. They make a fuss going around the gypsy, so I do that slowly and carefully. Rarely have much more than 150' out in 16 years of cruising. Switch ends and inspect chain/shackles annually and remark, you can rinse and then soak in OSPHO at the same time.

[SailingHannah]

Originally Posted by jsbartley

I had similar problem, and came across an interesting product called S2S (Ship2Shore). Look it up. They sell to navies and commercial shipping cos, but you can also buy retail from them. Its a wet coat that penetrates to steel and actually causes rust to flake off and not return. They have different grades where rating is for x # hours immersed...100 hrs, 500 hrs, etc. without washing off. I treated my chain a month ago, and initial impression is very positive.

What now after more than a month of use are your pros/cons of using the Ship-2-Shore spray to shut down the rust on the chain? It sounds like the spray is more like a film and doesn't dry. Does the film make a mess on the windless, anchor roller and/or chain locker? I also see RUST-OLEUM sells a galvanizing spray.

Anyone have any experience with either of these products or another on their anchor chain?

[MicHughV]

consider just buying new chain....
no, not from West Marine, but find a ship chandler store that caters to large ships.....several of these up and down the coast..
As an illustration....
West Marine...5/16" proof chain...$4.69/foot
Ship Chandler store...5/16" proof chain....$1.60/foot...
West Marine... 5/16" G4 chain...$5.59/foot
Ship Chandler store...5/16" G4 chain $3.29/foot

'jes sayin'.....