Stainless Steel... - SailNet Community

   Search Sailnet:

 forums  store  


Quick Menu
Forums           
Articles          
Galleries        
Boat Reviews  
Classifieds     
Search SailNet 
Boat Search (new)

Shop the
SailNet Store
Anchor Locker
Boatbuilding & Repair
Charts
Clothing
Electrical
Electronics
Engine
Hatches and Portlights
Interior And Galley
Maintenance
Marine Electronics
Navigation
Other Items
Plumbing and Pumps
Rigging
Safety
Sailing Hardware
Trailer & Watersports
Clearance Items

Advertise Here






Go Back   SailNet Community > On Board > Gear & Maintenance
 Not a Member? 
  #1  
Old 04-09-2008
merttan's Avatar
Senior Member
 
Join Date: Oct 2007
Location: CT
Posts: 317
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 8
merttan is on a distinguished road
Question Stainless Steel...

Hi everyone,
Another disturbing question from me
As an architect the grade of the steel is important on our design criteria for loads and size...
I was, however, wondering how to determine the so called stainless steel we use on our boats. I mean there are different grades for stainless steel like 316, which is good, and 304, which is not really "stainless" steel.
The importers of these materials also seem to be not sure what grade they are actually selling, thanks to our production line in China!

Example #1: All "stainless steel" bolts and screws I just changed last summer are all rusted out already!!! I bought them from a marine store that claimed they were "good" stainless steel. Some of those bolts and screws were installed in the cabin some out of the cabin... Yet they are rusted doesn't matter where they were used...

Example#2: The irony is that over 30 year-old original stainless steel parts of my boat are still shining and showing no signs of rusting... Yet, fairly new installed railings (apparently, the previous owner installed them about 3-4 years ago) are point rusting.

I do know you'll get what you pay for, however, where to get the right stuff is the question. What were your experiences with brands you used on your boat? Where did you get them and how satisfied are you?
I can use some information before changing the bolts and screws again this season...
__________________
" I refuse to engage in an intellectual battle with an unarmed man!"

Materialism: Buying the things we don't need, with money we don't have, to impress people who don't matter.
Reply With Quote Quick reply to this message Share with Facebook
  #2  
Old 04-09-2008
RAGTIMEDON's Avatar
Senior Member
 
Join Date: Apr 2007
Location: St Peters, MO
Posts: 389
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 8
RAGTIMEDON is on a distinguished road
For marine use, it is not the strength that matters as much as rust resistance. Plain carbon steel, even "soft" free machining steel, will make a screw that will hold parts together. But unless they are immersed in oil, rust will destroy 304 stainless in salt air. They call it stainless, but check it with a strong magnet before you buy! If a magnet has no attraction to it, it will probably last; if the magnet will pick up a screw, it probably will rust. That's a heck of a lot cheaper and more convenient than spectrographic analysis!
__________________
Don
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

1980 Endeavour 37 sloop, currently in the Mississippi near St Louis
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Reply With Quote Quick reply to this message Share with Facebook
  #3  
Old 04-09-2008
merttan's Avatar
Senior Member
 
Join Date: Oct 2007
Location: CT
Posts: 317
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 8
merttan is on a distinguished road
Quote:
Originally Posted by RAGTIMEDON View Post
That's a heck of a lot cheaper and more convenient than spectrographic analysis!
Oh yeah! It's a lot cheaper I'll try the magnet trick...
__________________
" I refuse to engage in an intellectual battle with an unarmed man!"

Materialism: Buying the things we don't need, with money we don't have, to impress people who don't matter.
Reply With Quote Quick reply to this message Share with Facebook
  #4  
Old 04-09-2008
DrB DrB is offline
Senior Member
 
Join Date: Mar 2007
Location: New England
Posts: 966
Thanks: 0
Thanked 7 Times in 7 Posts
Rep Power: 8
DrB will become famous soon enough
One Source

for quality SS is McMaster-Carr. I have had good luck with them. The magnet trick is a good technique.

McMaster-Carr Link

DrB
Reply With Quote Quick reply to this message Share with Facebook
  #5  
Old 04-09-2008
Francophobe
 
Join Date: Oct 2007
Location: Atlanta, GA
Posts: 168
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 8
TheFrog is on a distinguished road
Passivation

One often overlooked detail in stainless parts is the surface treatment. Yes, 316 is more resistant to rust than 304. But 316 can rust (at least surface stain) as well if the surface is not "passivated". Believe me, doctors are not happy if you give their instruments rust after just a couple cleaning/sterilization cycles. Passivation helps dramatically in reducing this. Of course, the chandler will probably not know what is being sold. Even in medical instruments you cannot tell and many vendors don't know, but this can be one of the big differences between high quality instruments and the cheap imitations from Asia.

For those who are curious passivation is an acid bath process that removes the iron oxides from the surface of the stainless. Every piece of stainless has some iron oxide on the surface after it is machined/formed. Removing these iron oxide seeds reduces the locations for rust to start.
__________________
_________________
"Ventarrón"
Flying Scot # 4964

Quote:
Golf is an exercise in Scottish pointlessness for people who are no longer able to throw telephone poles at each other.
-Florence King

To get the most from Sailnet, follow the link in
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
's signature.
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

Reply With Quote Quick reply to this message Share with Facebook
  #6  
Old 04-09-2008
SVAuspicious's Avatar
Mermaid Hunter
 
Join Date: Oct 2006
Location: on the boat - Chesapeake
Posts: 3,441
Thanks: 0
Thanked 116 Times in 103 Posts
Rep Power: 8
SVAuspicious will become famous soon enough
Read this:

Stainless Steel Information Knowledge alloys 316 304
Reply With Quote Quick reply to this message Share with Facebook
  #7  
Old 04-09-2008
sailingdog's Avatar
Telstar 28
 
Join Date: Mar 2006
Location: New England
Posts: 43,291
Thanks: 0
Thanked 11 Times in 11 Posts
Rep Power: 13
sailingdog is just really nice sailingdog is just really nice sailingdog is just really nice sailingdog is just really nice sailingdog is just really nice
BTW, 304 and 316 are both austentitic forms of marine grade stainless and non-magnetic...so the magnet test does little to tell you which it is. The cheaper, non-marine grade martenistic stainless steels are magnetic...and really should be avoided on a boat.

While 304 is a bit stronger (about 15% or so IIRC) than 316, the fact that it is far less corrosion resistant and prone to chloride ion stress cracking makes 316 a much better choice on a boat.
__________________
Sailingdog

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

Telstar 28
New England

You know what the first rule of sailing is? ...Love. You can learn all the math in the 'verse, but you take
a boat to the sea you don't love, she'll shake you off just as sure as the turning of the worlds. Love keeps
her going when she oughta fall down, tells you she's hurting 'fore she keens. Makes her a home.

—Cpt. Mal Reynolds, Serenity (edited)

If you're new to the Sailnet Forums... please read this
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
.

Still—DON'T READ THAT POST AGAIN.
Reply With Quote Quick reply to this message Share with Facebook
  #8  
Old 04-09-2008
merttan's Avatar
Senior Member
 
Join Date: Oct 2007
Location: CT
Posts: 317
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 8
merttan is on a distinguished road
Lightbulb Talking about medical supplies...

Will it be company privilege abuse if I get the metal things casted and cut in our titanium medical factory in Turkey? Nevermind for this boat, for the next one maybe
I'll see if I can get some manufacturers' production method information. Acid bath you say... I wonder if... No I shouldn't try it at home...
__________________
" I refuse to engage in an intellectual battle with an unarmed man!"

Materialism: Buying the things we don't need, with money we don't have, to impress people who don't matter.
Reply With Quote Quick reply to this message Share with Facebook
  #9  
Old 04-09-2008
pfatyol's Avatar
Swansea, MA
 
Join Date: Dec 2003
Location: Massachusetts
Posts: 98
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 11
pfatyol is on a distinguished road
If your really interested in passivation, it is covered in ASTM A967. Many different methods, but if you realy like your stainless to shine send it out for electro polishing. There a good number of firms that will either passivate or electro polish parts and hardware out there. Passivation does not remove the free iron from the surface of Stainless steel.
__________________
Patrick

S/V "Fat-Kat"
C&C 32, Hull #237
Mt. Hope Bay
Reply With Quote Quick reply to this message Share with Facebook
  #10  
Old 04-09-2008
merttan's Avatar
Senior Member
 
Join Date: Oct 2007
Location: CT
Posts: 317
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 8
merttan is on a distinguished road
Quote:
Originally Posted by SVAuspicious View Post
I think that I installed 304 on which I used cleaning solvents including but not limited to; bleach, oxyclean, citric acid based cleaners... And additionally, the rain we receive may have somewhat acidic characteristics...
I appreciate the link...
I guess, I'd better test the screws with solvents applied outdoor conditions for awhile before installing them.
__________________
" I refuse to engage in an intellectual battle with an unarmed man!"

Materialism: Buying the things we don't need, with money we don't have, to impress people who don't matter.
Reply With Quote Quick reply to this message Share with Facebook
Reply

Quick Reply
Message:
Options

By choosing to post the reply above you agree to the rules you agreed to when joining Sailnet.
Click Here to view those rules.

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:

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

 
Posting Rules
You may post new threads
You may post replies
You may post attachments
You may edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Combination stainless steel chain/ galvanized steel anchor Grigrigrigoris Gear & Maintenance 11 07-03-2005 03:46 PM
Stainless 101 sailnaway Gear & Maintenance 2 01-28-2005 05:02 AM
Keel Bolt Concerns Don Casey Gear and Maintenance Articles 0 10-12-2003 08:00 PM
Rust Never Sleeps John Kretschmer Buying a Boat Articles 0 02-27-2003 07:00 PM
Rust Never Sleeps John Kretschmer Gear and Maintenance Articles 0 02-27-2003 07:00 PM


All times are GMT -4. The time now is 02:44 PM.

Add to My Yahoo!         
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
SEO by vBSEO 3.6.1
(c) Marine.com LLC 2000-2012

The SailNet.com store is owned and operated by a company independent of the SailNet.com forum. You are now leaving the SailNet forum. Click OK to continue or Cancel to return to the SailNet forum.