Cruisers Forum
 


Join CruisersForum Today

Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on Cruisers Forums. Advertise Here
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 01-07-2020, 18:32   #1
Registered User

Join Date: Dec 2019
Location: Boston
Boat: Farr 50 Pilothouse
Posts: 235
ground tackle corrosion question

Is it best, from a corrosion perspective, to have all the parts of your ground tackle be the same (general) steel? ie. all stainless or all galvanized steel (chain, shackles, swivels, anchor)? or is it not a problem to have various components be stainless and in contact with galvanized components?
__________________

Muaddib1116 is offline   Reply With Quote
Old 01-07-2020, 20:08   #2
Registered User

Join Date: Nov 2019
Posts: 1,698
Re: ground tackle corrosion question

Quote:
Originally Posted by Muaddib1116 View Post
Is it best, from a corrosion perspective, to have all the parts of your ground tackle be the same (general) steel? ie. all stainless or all galvanized steel (chain, shackles, swivels, anchor)? or is it not a problem to have various components be stainless and in contact with galvanized components?
Mixing stainless and mild steel is bad news

Avoid dissimilar metals in sea water

If you fancy a stainless anchor you need stainless chain

Since this is money madness you are best advised to use all galvanized steel ground tackle
__________________

slug is offline   Reply With Quote
Old 01-07-2020, 20:24   #3
Registered User

Join Date: Dec 2019
Location: Boston
Boat: Farr 50 Pilothouse
Posts: 235
Re: ground tackle corrosion question

I'm buying a boat that already has stainless chain put on by the previous owner. It has a galvanized spade anchor on a stainless swivel on the stainless chain. I'm wondering if it is a big enough concern to think about getting a stainless anchor.
Muaddib1116 is offline   Reply With Quote
Old 01-07-2020, 20:28   #4
Registered User

Join Date: Nov 2019
Posts: 1,698
Re: ground tackle corrosion question

Itís up to you

An engineer would condemn the system

Itís possible that yacht ground tackle , since it is not wet for its entire life , is not as badly affected

A mooring system with dissimilar metals would be rejected
slug is offline   Reply With Quote
Old 01-07-2020, 21:23   #5
registered user
 
HankOnthewater's Avatar

Join Date: Dec 2012
Location: West Australia
Boat: plastic production yacht, suitable for deep blue water ;)
Posts: 675
Re: ground tackle corrosion question

I am not an engineer, and have no own experience with SS groundtackle.

I guess for most boats the gear lives on the bow/anchor locker, not in seawater.

When in seawater, yes a SS anchor is more noble than the zinc on the chain, so slowly the zinc will be sacrificed, and a rusty appearance will develop. This might take one or two years? One could then cut a meter from the chain, each year or second year.

To have a galvanised chain with a SS anchor, again the zinc on the anchor will slowly disappear, when immersed in seawater.

I must say, I have seen both scenarios, that is combining both SS and galvanised steel in the same groundtackle, where the zinc on chain or zinc on anchor still looks good after a few years. Maybe having the anchor dug into mud or sand is reducing the galvanic corrosion.

On edit: When I purchased my boat it had 2 galv. anchors on the bow and both was on galv chain, but both had a SS swivel between anchor and chain. Previous owners anchored very often,but... I could not see any loss of zinc on anchor or chain. BTW, I removed both swivels, for different reasons.

Re strength: if the zinc disappears from a few links..... will not have an affect strength at all. For the chain or anchor to lose its strength, then all the zinc need to have gone and the steel starting to be sacrificed. Unlikely scenario as the boatowner would have taken action by then.... I hope.

Of course, then there is the issue if SS should be used in groundtackle at all. But that is another can of worms.

When I purchased my boat it had 2 galv anchors on the bow, both on galv chain. Both had a SS swivel between anchor and chain. One anchor was used extensively over a period of 10 years or so (although was about twice that age I guess), that piece of chain and anchor were rusty. The other anchor and chain were 2 years old and had been the primary anchor since then, and in near perfect condition. BTW I removed both swivels, for different reasons.
__________________
Wishing you all sunny skies above, clear water below, gentle winds behind and a safe port ahead,
and when coming this way check https://www.cruiserswiki.org/wiki/Albany,_Australia
HankOnthewater is offline   Reply With Quote
Old 01-07-2020, 22:10   #6
Moderator
 
roverhi's Avatar

Join Date: Aug 2005
Location: Kona, Hawaii, Carlsbad, CA
Boat: 1969 Pearson 35 #108 & 1976 Sabre 28
Posts: 7,183
Send a message via Yahoo to roverhi
Re: ground tackle corrosion question

Stainless Steel is very close to mild steel in it's electrical potential. Yes there will be a slight imbalance but not enough to be serious situation. As HankOnthewater said, it's very common to have a SS swivel on galvanized chain and anchor. SS chain is not as strong as schedule 40 chain and wouldn't feel safe using it instead of galvanized steel because of its crevice corrosion issues.
__________________
Peter O.
'Ae'a, Pearson 35
'Ms American Pie', Sabre 28 Mark II
roverhi is offline   Reply With Quote
Old 02-07-2020, 00:25   #7
Senior Cruiser

Cruisers Forum Supporter

Join Date: May 2013
Location: Oregon to Alaska
Boat: Wheeler Shipyard 83' ex USCG
Posts: 2,827
Re: ground tackle corrosion question

Commercial fishing, I had a SS anchor with galvanized chain. Anchored 40-50 times a year. I had no issues. Some people that anchor for long periods put a zinc on the flukes or shank.
Lepke is offline   Reply With Quote
Old 02-07-2020, 05:58   #8
Registered User

Join Date: Dec 2019
Location: Boston
Boat: Farr 50 Pilothouse
Posts: 235
Re: ground tackle corrosion question

Thanks for the advice guys.
Muaddib1116 is offline   Reply With Quote
Old 02-07-2020, 06:32   #9
Registered User

Join Date: Dec 2019
Location: Boston
Boat: Farr 50 Pilothouse
Posts: 235
Re: ground tackle corrosion question

I suppose now I'm more worried about the strength of the stainless chain. I looked up some numbers and it only has 2/3rd the strength of galvanized g40 chain of the same size.
Muaddib1116 is offline   Reply With Quote
Old 02-07-2020, 09:20   #10
Registered User

Join Date: Dec 2019
Location: Currently cruising PNW
Boat: Nauticat 43 ketch
Posts: 252
Images: 5
Re: ground tackle corrosion question

Quote:
Originally Posted by Muaddib1116 View Post
I suppose now I'm more worried about the strength of the stainless chain. I looked up some numbers and it only has 2/3rd the strength of galvanized g40 chain of the same size.
Couple of suggestions-

1. The ground tackle you need depends upon how you intend to use it. SS chain is fine for all but storm anchoring conditions that would cause most weekend boaters to stay in their marina rather than go out. A full time cruiser or boater who lives on the hook would not want SS chain.

2. Concerned about corrosion? Try it and see. In most cases there is no need to fix a problem before you have it.
SV__Grace is offline   Reply With Quote
Old 02-07-2020, 09:50   #11
Registered User

Join Date: Nov 2019
Posts: 1,698
Re: ground tackle corrosion question

The crevice corrosion I see with SS chain happens in the chain locker when the chain tail is stacked

That chain pulled on the dock broke in the middle of its length

Close inspection revealed crevice corrosion
Attached Thumbnails
Click image for larger version

Name:	E0CC9BB1-AA46-4D13-9991-451C929644EA.jpg
Views:	77
Size:	454.4 KB
ID:	218564  
slug is offline   Reply With Quote
Old 08-07-2020, 08:36   #12
Registered User

Join Date: Oct 2015
Location: Newfoundland
Boat: Beneteau
Posts: 364
Re: ground tackle corrosion question

Quote:
Originally Posted by Muaddib1116 View Post
I'm buying a boat that already has stainless chain put on by the previous owner. It has a galvanized spade anchor on a stainless swivel on the stainless chain. I'm wondering if it is a big enough concern to think about getting a stainless anchor.
A permanent mooring would be of concern but an anchoring arrangement not so much. Easily monitored and dealt with if it becomes a concern. If you have money to burn it's your call.
nortonscove is offline   Reply With Quote
Old 08-07-2020, 09:24   #13
Registered User

Join Date: May 2011
Boat: Hitchhiker, Catamaran, 40'
Posts: 852
Re: ground tackle corrosion question

Better to keep your anchor and replace the chain. Stainless can fail with very little warning. Ditch the swivel.
Thumbs Up is offline   Reply With Quote
Old 08-07-2020, 09:34   #14
Registered User

Join Date: Aug 2009
Location: between the devil and the deep blue sea
Boat: a sailing boat
Posts: 19,480
Re: ground tackle corrosion question

I have sailed and anchored a boat with galvanized chain and SS anchor. Never had any issues, nor corrosion.


Not sure how this works if this spends years in the water (e.g. a permanent mooring). I would be tempted to have all galvanized kit then.


b.
barnakiel is offline   Reply With Quote
Old 08-07-2020, 10:41   #15
Marine Service Provider

Join Date: Mar 2016
Location: Madeira
Boat: Moody 41
Posts: 17
Re: ground tackle corrosion question

I have driven quite a number of larger vessels with stainless anchors and galv stud link chains. The stainless anchors were for appearance more than anything. These vessels were surveyed every 5 years for class. Never a problem with the chain or the surveys. I think it's fine.
__________________

dnight is offline   Reply With Quote
Reply

Tags
corrosion

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Negative Ground vs Positive Ground History Question. Wotname Electrical: Batteries, Generators & Solar 20 14-05-2017 11:43
To ground or not to ground an aluminum arch...that is my question. chrtucke Electrical: Batteries, Generators & Solar 9 06-10-2014 23:17
For Sale: Ground Tackle Randyonr3 Classifieds Archive 0 03-10-2010 08:45
Islander 29 - Ground Tackle Recommendations dissent Anchoring & Mooring 7 13-06-2010 12:06
Assess My Ground Tackle b-rad Anchoring & Mooring 13 15-04-2010 19:47

Advertise Here


All times are GMT -7. The time now is 14:44.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2020, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.