unforgiving stainless.... - SailNet Community
 1Likes
Reply
 
LinkBack Thread Tools
post #1 of 12 Old 12-31-2011 Thread Starter
Senior Member
 
Join Date: Sep 2006
Location: Scotland
Posts: 2,364
Thanks: 0
Thanked 11 Times in 11 Posts
Rep Power: 9
 
unforgiving stainless....

Enough to chill you to the marrow.

Leave is short on oxygen and give it some chlorides from seawater, and this is what you get.

Have a look at the video at around 3.20...

replacing Tayana 37 chain plates - YouTube

In the spring, I will look at mine. I've got 6 of them on the sides of my ship, a Union Polaris 36. Last time I looked (about 12 years ago) they were OK. I will have to look again.

Note where it is oxygenated, it shows no distress, and very little corrosion. Where hidden, and wet, and de-oxygenated, and chlorinated(?), it rots like biscuit.

Rockter.
.
Rockter is offline  
Quote Quick Reply Share with Facebook
Sponsored Links
Advertisement
 
post #2 of 12 Old 12-31-2011
Senior Member
 
Capnblu's Avatar
 
Join Date: Mar 2006
Location: Squamish
Posts: 659
Thanks: 0
Thanked 4 Times in 4 Posts
Rep Power: 10
 
Imagine the corrosion that guy will get with stainless, and cold rolled steel, just in the humid environment!

Why, why, why?
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

I Don't Know! I Don't Know!
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Capnblu is offline  
Quote Quick Reply Share with Facebook
post #3 of 12 Old 12-31-2011
Jnoiur Mebemr
 
StormBay's Avatar
 
Join Date: Sep 2010
Location: Bahamas
Posts: 180
Thanks: 1
Thanked 10 Times in 9 Posts
Rep Power: 5
 
When we recently bought our boat (1985 HC41) we found 5 cracked chainplates, one cracked whisker stay and most of the bolts And nuts for them crumbled! After I removed some of the bolts, I was able to break them simply by tapping them on the vice (see video) though they looked nice and shiny when they were installed. scary is an understatement.. Stainless is evil!

Chainplate bolts Hans Christian 41 - YouTube



These are from one chainplate alone..

Yu & Frank

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
StormBay is offline  
Quote Quick Reply Share with Facebook
post #4 of 12 Old 12-31-2011
Jnoiur Mebemr
 
StormBay's Avatar
 
Join Date: Sep 2010
Location: Bahamas
Posts: 180
Thanks: 1
Thanked 10 Times in 9 Posts
Rep Power: 5
 
Quote:
Originally Posted by capnblu View Post
imagine the corrosion that guy will get with stainless, and cold rolled steel, just in the humid environment!
+1

Yu & Frank

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
StormBay is offline  
Quote Quick Reply Share with Facebook
post #5 of 12 Old 01-01-2012 Thread Starter
Senior Member
 
Join Date: Sep 2006
Location: Scotland
Posts: 2,364
Thanks: 0
Thanked 11 Times in 11 Posts
Rep Power: 9
 
Stormbay :

I have a Union Polaris 36.
Last time I took the chainplates bolts out (1998?), they looked fine, and the chainplates.
Stainless is terribly unforgiving if it gets de-oxygenated when seawater is around.
Those bolts and nuts you pictured are showing classic chloride attack. In the presence of oxygen, even oxygenated seawater, it simply does not happen.
But how the heck do we get oxygen into chainplate fasteners that are seawater wet?
One of my stern-plate bolts was eaten almost right through back in 1992. I will need to check those too, soon. Between tides will do it, I guess. This far north, 57 degN, we have big enough tides.

I will have a look at all of my chainplates in the spring.
Does bronze work better?
Do we need carbon fibre chainplates?

Right now, I am in freshwater, and have been for some time. Beautifully-clean Loch Ness freshwater too, if a bit "peaty". I notice that the bronzes adore it. Maybe I need to stay there?
.

Last edited by Rockter; 01-01-2012 at 07:45 AM.
Rockter is offline  
Quote Quick Reply Share with Facebook
post #6 of 12 Old 01-01-2012
Jnoiur Mebemr
 
StormBay's Avatar
 
Join Date: Sep 2010
Location: Bahamas
Posts: 180
Thanks: 1
Thanked 10 Times in 9 Posts
Rep Power: 5
 
Rockter;
According to our previous owner our chainplates and bolts were also pulled and checked 2001 after cracks were discovered on the cransiron. According to him all looked fine and were cleaned and reinstalled. One of the biggest problems with our Taiwanese built boats tends to be the quality of stainless used on them which was more than likely not 316 (there was little quality control at the asian foundries at that time) On our boat, we can see evidence of this everywhere and have discovered hairline cracks throughout most of our original stainless parts (dye testing can help se what your eyes can not).

There was a compelling article in both Practical Sailor and another mag (can't remember witch one) regarding titanium for use in these situations. Titanium is lighter, stronger, doesn't suffer crevice corrosion, and is extremely noble (though that could be a bad thing as well) compared with stainless. The biggest down side that I can see is the fact that it remains pricey. The site that both articles pointed to for titanium parts and custom chainplates is Allied Titanium - Home Page (no affiliation ) It looks although they have both a Bobstay Plate (item 0035380) and a Bowsprit plate (item 0035379) on hand for a Union Polaris 36; I am sure they can make other parts as well.

Yu & Frank

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

Last edited by StormBay; 01-01-2012 at 01:44 PM.
StormBay is offline  
Quote Quick Reply Share with Facebook
post #7 of 12 Old 01-01-2012
Senior Member
 
mitiempo's Avatar
 
Join Date: Sep 2008
Location: Victoria B.C. Canada
Posts: 7,487
Thanks: 0
Thanked 94 Times in 85 Posts
Rep Power: 8
   
It doesn't matter much if the water is salt or fresh - it is the lack of oxygen that causes the problem. Keel bolts have a salt water issue (in salt water regions) but chainplates mostly have fresh water issues as it is the rain and leaks that are the problem. The trick is to keep them dry where they pass through the deck.

Brian
Living aboard in Victoria Harbour
mitiempo is offline  
Quote Quick Reply Share with Facebook
post #8 of 12 Old 01-01-2012 Thread Starter
Senior Member
 
Join Date: Sep 2006
Location: Scotland
Posts: 2,364
Thanks: 0
Thanked 11 Times in 11 Posts
Rep Power: 9
 
mitiempo :

Chlorides absolutely feast on chrome when there is no oxygen.
Below the water line in salt water, it is murder.
We cannot corrode without a reactant.
Fresh water really is far more forgiving.
Rockter is offline  
Quote Quick Reply Share with Facebook
post #9 of 12 Old 01-01-2012 Thread Starter
Senior Member
 
Join Date: Sep 2006
Location: Scotland
Posts: 2,364
Thanks: 0
Thanked 11 Times in 11 Posts
Rep Power: 9
 
Stormbay :

I'd better get a crack testing kit.
This may get expensive in Titanium, methinks.
Rockter is offline  
Quote Quick Reply Share with Facebook
post #10 of 12 Old 01-01-2012
Senior Moment Member
 
SloopJonB's Avatar
 
Join Date: Jun 2011
Location: West Vancouver B.C.
Posts: 11,363
Thanks: 59
Thanked 67 Times in 64 Posts
Rep Power: 5
 
Quote:
Originally Posted by Rockter View Post
Does bronze work better? .
In a word, YES. Bronze is the ultimate marine metal - the teak of metals

I have seen pictures of bronze bits pulled up from ancient Roman galleys that were almost as good as new - 2K years old and older, submerged in the Med the whole time.

Stainless is shiny pretty and it's more easily available as well as cheaper but bronze is better - prettier too if you can keep it polished but that's worse than maintaining varnish.

I, myself, personally intend to continue being outspoken and opinionated, intolerant of all fanatics, fools and ignoramuses, deeply suspicious of all those who have "found the answer" and on my bad days, downright rude.
SloopJonB is offline  
Quote Quick Reply Share with Facebook
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the SailNet Community forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
Please note: After entering 3 characters a list of Usernames already in use will appear and the list will disappear once a valid Username is entered.


User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Similar Threads
Thread Thread Starter Forum Replies Last Post
spotless stainless inshallamiami General Discussion (sailing related) 0 06-21-2010 01:31 PM
Stainless or Galvanized? capecodphyllis Gear & Maintenance 18 12-12-2006 02:57 AM
Stainless 101 sailnaway Gear & Maintenance 2 01-28-2005 05:02 AM
Stainless bista Gear & Maintenance 20 11-19-2004 04:22 PM

Posting Rules  
You may post new threads
You may 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 On
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome