Anchor chain corrosion

[mj603]

I have 5/16 hi tensile galvanized anchor chain. It has developed hardish white corrosion in various areas on the chain that sits in bottom of anchor locker. This portion of the chain has never been in saltwater. Boat is about 9 months old. I had rinsed out locker area with fresh soapy water to rid locker of any salt remaining from anchor use. This seems not to have cured problem. I have been keeping the hatch closed but am now keeping it cracked open to allow air in.

2 questions -

1. how much corrosion is ok before chain is no longer safe
2. any tricks to keep corrosion off (we have not always rinsed chain after use)

[trantor12020]

1. when the chain starts thinning, you should start to get worried.
2. oiling it may help but environmentally unfriendly.
normally galvanised chain should last for years before it becomes a problem. the real problem part is the "Missing Link" chain connector. they rust alot faster than your galvanise chain and that's prob where the chain system will break if it should.

[camaraderie]

MJ...no worries and welcome. The white stuff is normal and nothing to orry about. RED RUST means the galvanization has failed and you need to start paying attention to how much of the link has been eaten. Sounds like you are a long way from that.

[Lion35]

Welcome, as mentioned above it sounds like you're fine and i believe your practice of fresh water rinsing the chain will help a lot in the long run.

For extra prevention I put Dri-Dek tiles under my rode. My thinking was it would stop pockets of water pooling around the bottom of the rode and it would help abrasion of the hull a bit (wood hull, but can't hurt with a glass hull.) I only did this a few years ago so it's to soon to tell if the panels will make a difference.

[bwindrope]

Above ideas are good. Another useful thing to do is to reverse the sides of your chain each season. As part of your spring work, reverse the end of your chain connected to your anchor so that it is not always the same links sitting on the bottom.

I'm a cruiser in deep waters and so carry several hundred feet of chain. Rarely use the last 50 feet or so, and despite fresh water rinsing back at the dock, find it gets unhappy being at the bottom of the chain locker and likes to see sunlight like the rest of us.

I like the idea of putting draining tiles down there. Just makes sense.

Good luck, and your chain sounds fine for now.

[trantor12020]

bwinrope, I'm just thinking about redoing the rope chain splice as it looks wore and reversing the chain sounds like a good idea.

[bwindrope]

Well, good, try switching ends. The primary benefit is probably just examining your entire setup each year. I've come to believe that anchor chains and rodes follow the same rule as everything else on my boat: Either follow a scheduled routine of maintenance and service or it will fail at the worst possible time.

I use a three strand rode and so do a direct to chain splice. Because this does not get much use due to it being several hundred feet behind my anchor, it doesn't get chafed much. However, I enjoy doing that splice, and am always trying to improve the elegance and strength of it. It only takes a minute now.

Due to spending so much time working on Aeolus, I can't help but get philosophical about it all. This has led me to seeing how dark neglected places on the sailboat always originate the worst troubles (galvanic corrosion, rusted chain, unserviced winches, etc.) and this is certainly true in my head as well!!!

Shine the light, shine the light.

[Cruisingdad]

Originally Posted by camaraderie

MJ...no worries and welcome. The white stuff is normal and nothing to orry about. RED RUST means the galvanization has failed and you need to start paying attention to how much of the link has been eaten. Sounds like you are a long way from that.

I did not know about the red rust. Interesting. Thanks.

- CD

[sailingdog]

CD--

Red rust is usually IRON OXIDE based, and means that the iron in the steel of the anchor chain is leaving... That's generally bad for an anchor chain. The white stuff is zinc oxide, yes, like the stuff the life guards used to put on their noses at the swimming pool... which isn't the strong stuff holding the boat to the bottom, but just the surface coating on top of the strong stuff--steel--that is holding the boat to the anchor.

[captainchetco]

I have read in numerous texts that high carbon steel "rusts" more readily than lower carbon steel. An ACCO representative told me that was not true. Does anyone have a diffinitive answer on this?