Rusty chain woes !

[Hedgehog2]

My mooring chain is rusty and discolouring the foredeck.
Swing mooring, half a mile up river, chain hangs in water during Winter when boat on land.

When I spoke to the guys who maintain the moorings, he said that's what happens to chains.

Is this inevitable ?
Or can you buy chain that doesn't rust ?
Did they lay it with inferior quality?

 

[Yngmar]

Yup, galvanized chains rust sooner or later. You can buy stainless steel chain, but it's very expensive for good quality and has slightly different properties to be aware of.

Why is the chain on the deck though? Isn't that part usually rope? That's what I'd like to know

To clean up rust stains from gelcoat, use oxalic acid (cheaply available in crystal form).

 

[Hedgehog2]

Yup, galvanized chains rust sooner or later. You can buy stainless steel chain, but it's very expensive for good quality and has slightly different properties to be aware of.

Why is the chain on the deck though? Isn't that part usually rope? That's what I'd like to know

To clean up rust stains from gelcoat, use oxalic acid (cheaply available in crystal form).

Thanks..
On our river, I think tends to be rope from sea bed to buoy, then chain to cleat.

 

[Yngmar]

That's pretty much the opposite of most moorings I've seen. Is your river in a parallel universe?

 

[Neeves]

Chain on the seabed, river bed, loses gal quickly (its in use 24 hours a day). Often a mooring contractor will not use gal chain because the gal is worn away quickly. The gal coating is commonly 70 microns - if you think what 70 microns is - its not surprising it does not last, or it is surprising how long it lasts in an abrasive environment. If its a muddy river - the muds might be acidic - then the gal is being dissolved.

I'm not entirely sure why you have chain at all, see Yngmar's diagram. You could use rope from buoy to cleat - if abrasion is an issue - thread the rope through a decent piece of hose pipe - if/when it looks as if it will wear through - replace the hose pipe

Our moorings in Sydney are all rope - but with a sweep chain (ungalvanised) on the seabed. The mooring rope from sea bed to buoy, floats, as does the mooring pennant. Our buoys don't add buoyancy (or its minimal) - they simply mark the spot.


I think you need to ask your mooring contractor why you have a chain pennant - as well as changing the pennant - change your mooring contractor if you do not a satisfactory answer. Take your tender and go on a bit of a wander and have a look at other moorings by your contractor and other contractors.

Jonathan

 

[PhillM]

My mooring is similar to the pic too and I am surprised that you have a chain on the foredeck. IF you should have then I would put it in a clear plastic pipe so that it reduces chafe and also reduces the rust stains. Old firehose would work too, but not be as easy to see the chain and inspect for damage,

 

[Neeves]

This our mooring. 1t concrete block, large sweeper chain to which is attached a lighter sweeper chain. The big chain moves in strong wind when the light chain might lift and offers the protection to snatch loads. The man is holding the mooring line that extends to the buoy on the surface - you can see the sort of buoy on the yacht behind, the little yellow buoy. We have our own pennant to our yacht, with hose pipe for abrasion protection.



At the sea bed the floating rope is spliced to the chain and the splice protected with hose pipe - as most of the time all the chain is on the seabed + the splice. If the mooring is inadequately serviced eventually something fails - but in this case its the chain that has failed (not the protected splice).

Not much need for galvanised chain - the gal will last a very short time.


Jonathan

 

[sarabande]

Some moorings at Plymouth are laid with polysteel riser which seems to be good at lasting. Certainly rope bridles to prevent damage to hull from overrunning the buoy; also easier on the hands and fingers.

 

[Stemar]

Mine was chain and I had the same problem, plus the boat used to swing around a lot in gusty weather. I replaced the single chain with a Polysteel bridle. Polysteel is UV resistant, and it floats, which is always an advantage when you're trying to pick up your mooring in difficult conditions.

A a Brummel splice to make the eye in the middle, with a hard eye to attach to the mooring, and conventional eye splices on the end. Job done, and my monohull sat better too. Now I've got a cat, the bridle's even more important.

 

[oldharry]

I did my own mooring for nearly 30 years, and always used black chain for the ground and risers. As above, using galvanised chain is just a waste of money, and doesnt increase the life of the chain by a single day. The pennant was always galvanised chain, replaced most seasons or as soon it showed signs of rusting. NEVER use stainless shackles or seizing wire with galv chain, it will eat the galvanising off in weeks! I'm against using rope strops because of unpredictable chafe. Chain can be fed through a plastic tube to protect the gelcoat if that's an issue, and it reduces the chance of rust stains where the chain crosses the deck to the mooring point.

I never left the pennant chain hanging in the water over the winter: guranteed to rust and get covered with marine life by spring.

 

[Praxinoscope]

Over the years I have had both swinging and fore & aft moorings, but have never had the chain come aboard, it has always been rope, currently octuplait strops.
Obviously a diagram of swinging mooring, but equally valid for fore & aft Yngmar’s #4 is the way I would go.

 

[vyv_cox]

We replaced our galvanised 1/2 inch pickup chain every two years. It was only a few metres long (buoy to boat) so not expensive.

 

[andsarkit]

I have a galvanised chain from the top of the buoy to the deck cleat with a back up rope in case a shackle fails. It lasts about 5 years as it is removed every winter when the boat is ashore. If I am off the mooring for a couple of weeks the chain and rope is covered in marine growth so it would be disgusting if left in the water over the winter.
I don't trust just rope as I have seen it chafe quickly during a gale but I might reconsider using it if it was polysteel which seems immune to chafe and UV.
I think that Dart Harbour used to insist on a chain but I see their mooring specification is currently being revised so might well now allow the use of rope.

 

[Yealm]

Wonder if way to go is chain just up over the bowel roller (so no chafing issues) then rope to cleat, on either side.

Or just replace chain every 2 years, as per vyv_cox.

 

[jdc]

I think that the choice of strop is between those attached on the top of buoy versus those attached below the buoy (but above the swivel if present).

For the former I use 28mm 8-plait polysteel which floats and never gets tangled with the riser (and is easy to pick up and kind to the boat). If it gets any chafe I replace it - no very great cost.

For the latter (strop attached below the buoy) I use sinking rope. I have tried both chain and polyester 3-strand (but good and thick!), and prefer the rope.

For both, the strop is removed as soon as the boat is hauled out, inspected and remade over the winter if chafed, and refitted in spring. I never use chain when the strop is attached to the top of the buoy, but your opinion may be different. I also never attach two strops; this strikes me as silly I'm afraid. If the conditions are so bad that the main strop chafes through, how long will a secondary one last? So it brings illusory advantage imho, and as a disadvantage it will definitely get in a tangle around the primary strop, and possibly act as an additional source of chafe.

 

[andsarkit]

I also never attach two strops; this strikes me as silly I'm afraid. If the conditions are so bad that the main strop chafes through, how long will a secondary one last? So it brings illusory advantage imho, and as a disadvantage it will definitely get in a tangle around the primary strop, and possibly act as an additional source of chafe.
[/QUOTE]
I have agree. The only time the backup rope chafed through was when it twisted around the chain during a serious gale. I will have to check current rules with Dart Harbour as they may have changed. Polysteel looks like a better option