Anchor chain combo

[teejayevans]

Originally Posted by wsmurdoch

By the way, is there some way to train the galvanic corrosion gremlins to attack the cheap inch thick zinc hull anodes rather than the expensive microns thick zinc galvanizing on the anchor chain?

They are not electrically attached, try attaching a fish anode to your chain.
Tom

[wsmurdoch]

We were on the boat last week for a couple weeks of sailing on the North Carolina Sounds before hurricane Irene appeared and we returned from Bath to New Bern to prepare for the storm.

The anchor chain touches the boat's metal in three places. It sags between the anchor roller and the windlass touching the bow fitting. It wraps around the windlass chain wheel. And, it touches the hawse hole in the windlass before dropping into the chain locker. I measured the resistance of all three spots. All were below 1 ohm although the spot at the bow fitting was hit or miss as the chain moved around. The resistance link to link in the chain is also under 1 ohm.

The windlass motor (and hence the windlass body) is connected to the boat DC ground system by a #8 wire that goes to the underwater metal plate mounted forward and to starboard of the keel. All of the underwater metal and the engine are connected to the plate.

I guess the surface area of each link in the chain is 2 square inches. With 12 or so links per foot, there would be 2400 square inches in 100 feet of chain. There is far more underwater area of zinc exposed on the chain of my anchored boat than on the few square inches of zinc anodes. Why wouldn't the chain galvanizing be as subject to galvanic attack as the anodes?

Bill Murdoch
1899 PSC 34
Irish Eyes

[teejayevans]

Originally Posted by wsmurdoch

I guess the surface area of each link in the chain is 2 square inches. With 12 or so links per foot, there would be 2400 square inches in 100 feet of chain. There is far more underwater area of zinc exposed on the chain of my anchored boat than on the few square inches of zinc anodes. Why wouldn't the chain galvanizing be as subject to galvanic attack as the anodes?

Isn't distance a factor? Those electrons have to travel from the chain to your prop? I assume this is why my bronze seacocks don't have zincs (they are electrically isolated).

Good luck with the storm, hope it jogs east of you.
Tom

[cheoah]

Hi there, I bought my dream boat last summer in SW Florida. It came with a 35 lb CQR w 10 feet of stainless chain and what looked like 150' of 5/8 double braid in marginal condition. Also has 35 lb Bruce with another 10' stainless chain and 150' three strand. Moved stainless chain to danforth stern anchor.

I left the Bruce the same but for the CQR I bought a 50' section of 5/16 ht and spliced on 150' 5/8 three strand. This will eventually be my secondary rode but all I could afford for now. It's also all I really need for our deepest anchorages in the SE like the other captain said, in around 25' water.

Also have FX 23 under port settee.

Is this sufficient for northern Bahamas? Maine? Chain is expensive, and I'd love to have at least 150' but $$ is tight and I don't want to buy enough chain for the pacific to rot in the chain locker while I anchor in 10-20' water until retirement.

Also have manual windlass which is not as easy as I thought. Singlehanding this summer I sailed into cape lookout late one night and anchored in a breeze. Somehow I totally blew it and anchored too close to a boat so had to get my gear up and reset. Not easy. I'm a 200 lb farmer, but by no means superman with my blown out disks. Amazing the difference in weighing anchor compared to my old 5 ton boat. I Guess the windage on top of extra weight adds to the load.

Curious about the muir windlass mentioned earlier in thread, I think. Can't reference thread on iPhone. Does it have more mechanical advantage than the stock lewmar?


Chase

[steneck]

Hi Folks,

I've been sailing around Maine for the past 20 years or so and lived on a trimeran in St Croix for a few years in the 1970s. I've never felt the need for the length of chain some of you have. I currently have a 33 lb Bruce with 50' 5/16" HT chain and 300' 5/8 nylon rode. My backup is a Danforth 3000 HT with 30' 1/4" HT chain with 180' 1/2" braided line.

On rare occasions I need to anchor in deeper or more exposed locations that I'd like but I've never had a problem holding. I've always assumed that if the chain is sufficient to transfer pull horizontally on the sea floor you are getting all you can expect from your chain. Have some of you had your long chains pull tight and drag?

Bob Steneck
Alaria
1992 PSC 34
Christmas Cove, Maine

[teejayevans]

Originally Posted by steneck

I've always assumed that if the chain is sufficient to transfer pull horizontally on the sea floor you are getting all you can expect from your chain. Have some of you had your long chains pull tight and drag?

You should use a snubber if anchoring all chain to provide some elasticity. You are correct about the horizontal pull but there are other reasons that using all chain is nice:
1. easier to stow
2. when in tidal waters and the boat is aligned with the current, a nylon rode can end up getting caught in the rudder/prop, where chain will hang more vertically
3. superior abrasion resistance.

Tom

[niftynickers]

We have been cruising the east coast from Maine to the Bahamas for the last eight years on our C37.Our everyday anchor is a 44 lb Bruce with 100' of 3/8 BBB and 200' of 5/8 nylon 3 strand.99% of our anchoring is in 20'of water or less meaning that the nylon rarely gets wet unless the wind picksup or a storm threatens.The only anchorages that I can think of that require more than the chain are Block Island and Newport RI.
I also acknowledge anchoring on the west coast requires much more rode having sailed in the Channel Islands of Calif.
When using only chain I always use a nylon snubber to absorb the shock load.
Another very important item of gear on the east coast is a washdown pump and hose as most anchorages are very muddy especially the Chesapeake and mid Atlantic states.
Dianne and Chuck Burke S/V NiftyNickers C37 #139