Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 26-06-2012, 04:13   #1
Registered User

Join Date: Feb 2012
Location: Karpaz Gate Marine - Cyprus
Boat: Moody 44
Posts: 25
Send a message via Skype™ to winckyst
moody 44 1995 Keel Bolts

Dear all!
The keel bolts, nuts and plates in my new (old!)moody 44 are all badly corroded. bilge was floated cause of flair of hot water system but now very very dry!
First thought was to drop down keel and make it all new but after deep search (mainly via Moody owner association web site) we understood there is a big chance that bolts are ok and they are bad looking only from the upper side (the part you see in the bildge).
1/ do you have any relevant info about it?
2/ in case I need to replace the bolts+nuts+plates: do you recommend me to use S/S bolts or to stick to moody plane and use mild steel?
3/ according to your advice, where can I get all the 14 nuts and what will be the price for them?
similar issue(not my moody)in this kink:[URL="http://www.moa.myzen.co.uk/cgi-bin/discus/board-auth.cgi?lm=1231606798&file=/1159/10047.html."]
attached few photos.
we would like to start rift in 2 weeks time in Almerimar (Spain) ship yard.
thanks alot for any help!!!
Attached Thumbnails
Click image for larger version

Name:	KEEL2.jpg
Views:	191
Size:	123.6 KB
ID:	42755   Click image for larger version

Name:	KEEL4.jpg
Views:	170
Size:	162.4 KB
ID:	42756  

Click image for larger version

Name:	KEEL5.jpg
Views:	154
Size:	197.0 KB
ID:	42757   Click image for larger version

Name:	KEEL6.jpg
Views:	205
Size:	128.0 KB
ID:	42758  

Click image for larger version

Name:	KEEL1.jpg
Views:	197
Size:	126.1 KB
ID:	42759   Click image for larger version

Name:	KEEL3.jpg
Views:	154
Size:	155.6 KB
ID:	42760  

__________________

__________________
winckyst is offline   Reply With Quote
Old 26-06-2012, 06:56   #2
Registered User
 
neilpride's Avatar

Join Date: Jul 2009
Location: in the world
Boat: csy 44 tall rig.
Posts: 3,099
Re: moody 44 1995 Keel Bolts

Looks really corroded, keel is lead? iron?
Im not sure about the bolts and nuts , but the backing plate can be SS made it in a local shop, and the bolts and nuts need to be with the builder specifications in terms of loads , elongation , shear , etc.. is not a simple hardware store bolt, if you can contact Moody about bolts specification can be a bonus.

The bolts at the picture looks very bad but you can try to do this test, take a wire brush or a circular wire brush and clean the top of the bolts , see if there is still healty thread around and clean all the loose scale , cut just a 1 mm on top of the bolts , if you get a bright and clean cut and the corrosion is just superficial and the thread is ok there is a chance to save the bolts, this is just in case you are determined to not drop the keel and do the whole thing new.

Btw, SS is the way to go, but need to be with the same strenght as the Mild steel bolts.
Good luck!!
__________________

__________________
neilpride is offline   Reply With Quote
Old 26-06-2012, 07:21   #3
Registered User
 
neilpride's Avatar

Join Date: Jul 2009
Location: in the world
Boat: csy 44 tall rig.
Posts: 3,099
Re: moody 44 1995 Keel Bolts

This 2 pics come from a guy with the same problem, boat is a moody 44 to.

1. PIC SHOW corrosion and rust
2. Pic after cleaning and brushing all the corrsion.
Attached Thumbnails
Click image for larger version

Name:	IMG_0034222222.jpg
Views:	564
Size:	68.7 KB
ID:	42768   Click image for larger version

Name:	keel4.jpg
Views:	341
Size:	43.5 KB
ID:	42769  

__________________
neilpride is offline   Reply With Quote
Old 26-06-2012, 07:30   #4
Registered User

Join Date: Mar 2010
Location: Alaska
Boat: Truant Triad 37 Cutter
Posts: 346
Re: moody 44 1995 Keel Bolts

Hard to imagine Moody doesn't use ss bolts with their attention to quality. Makes me wonder because it seems like a no brainer.
__________________
seahag is offline   Reply With Quote
Old 26-06-2012, 07:31   #5
Registered User

Join Date: Feb 2012
Location: Karpaz Gate Marine - Cyprus
Boat: Moody 44
Posts: 25
Send a message via Skype™ to winckyst
Re: moody 44 1995 Keel Bolts

do you have is mail or link where i can contact the guy?
thanks!!!
__________________
winckyst is offline   Reply With Quote
Old 26-06-2012, 07:32   #6
Registered User

Join Date: Feb 2012
Location: Karpaz Gate Marine - Cyprus
Boat: Moody 44
Posts: 25
Send a message via Skype™ to winckyst
Re: moody 44 1995 Keel Bolts

true
many moodies got the same problem.
keel is clast iron by the way
__________________
winckyst is offline   Reply With Quote
Old 26-06-2012, 07:39   #7
Registered User
 
neilpride's Avatar

Join Date: Jul 2009
Location: in the world
Boat: csy 44 tall rig.
Posts: 3,099
Re: moody 44 1995 Keel Bolts

Quote:
Originally Posted by winckyst View Post
do you have is mail or link where i can contact the guy?
thanks!!!
Hee no, i stole the pics from another forum , Ybw ...
But look, steel when rust and corroded looks pretty ugly, sometimes you still have healty material after a good cleaning process.
__________________
neilpride is offline   Reply With Quote
Old 26-06-2012, 10:27   #8
Moderator
 
noelex 77's Avatar

Cruisers Forum Supporter

Join Date: Jul 2007
Location: Living on dirt waiting for our new yacht to be built.
Boat: Half built Bestevaer.
Posts: 10,618
Re: moody 44 1995 Keel Bolts

It's very hard to determine the condition of the keel bolts looking at the bits you can see. Steel is not a great material for these bolts, but not quite as stupid as you would imagine as the ordinary 304 or 316 SS suffers crevice corrosion if there is any moisture in the joint.
I don't understand why manufacturers do not specify some of the exotic SS that are resistant to crevice corosion, bronze or titanium depending on the keel material. The cost of dropping the keel to inspect the bolts is much more than using the best material for the job in the first place.
__________________
noelex 77 is offline   Reply With Quote
Old 26-06-2012, 14:20   #9
Senior Cruiser
 
bstreep's Avatar

Cruisers Forum Supporter

Join Date: Oct 2007
Location: San Antonio, TX/Port Aransas, TX
Boat: 1990 Macintosh 47, "Merlin"
Posts: 2,274
Re: moody 44 1995 Keel Bolts

We are looking at a similar issue - just no where near that bad! The nuts can be cut off using a nut splitter. You can then put new ones on. You should replace them with the SAME type nuts. Steel is much stronger than stainless - so unless someone tells you it's OK, don't just replace carbon steel with stainless steel.
__________________
Bill Streep
San Antonio/Port Aransas, TX
bstreep is offline   Reply With Quote
Old 26-06-2012, 14:32   #10
Moderator
 
noelex 77's Avatar

Cruisers Forum Supporter

Join Date: Jul 2007
Location: Living on dirt waiting for our new yacht to be built.
Boat: Half built Bestevaer.
Posts: 10,618
Re: moody 44 1995 Keel Bolts

Quote:
Originally Posted by bstreep View Post
We are looking at a similar issue - just no where near that bad! The nuts can be cut off using a nut splitter. You can then put new ones on. You should replace them with the SAME type nuts. Steel is much stronger than stainless - so unless someone tells you it's OK, don't just replace carbon steel with stainless steel.
The tensile and yield strength of steel and stainless steel is generally resonably similar, but does vary considerably with the different grades.
Keel bolts are generally massively over specified, but it doesn't take much corosion to make them marginal. Avoiding corrosion is the key to keeping your keel attached.
__________________
noelex 77 is offline   Reply With Quote
Old 26-06-2012, 21:23   #11
Marine Service Provider

Join Date: May 2012
Location: New Orleans
Boat: We have a problem... A serious addiction issue.
Posts: 3,940
Re: moody 44 1995 Keel Bolts

I am actually in the process of working with some keel and boat manufacturers to switch from steel or 316 over to titanium. Both of these typical metals have real problems being used as keel bolts, and honestly I wouldn't recommend either. As pictured steel rusts from the top down, and is terrible in applications subject to salt water intrusion. 316 while much more corrosion resistant suffers from crevice corrosion and frankly a bilge is about the worst place in a boat for crevice corrosion to start and propagate.

By comparison Grade 5 titanium is about 2.5 times stronger than 316, and roughly 1.5 times the tensile strength of most mild steel and compares reasonably with all but the highest tensile strength steels. It also is completely non-corrosive in salt water environments (at tempratures below 215F). It does cost a little more at the front end, but since it is a permanent solution, it is gaining traction in the keel industry.

It you decide to replace them, Mars Keels has a nice guide to how to do it for lead keels. It is a pretty major project, and requires melting lead, but doable.
__________________
Greg

- If animals weren't meant to be eaten then they wouldn't be made of food.
Stumble is offline   Reply With Quote
Old 26-06-2012, 21:39   #12
Marine Service Provider

Join Date: May 2012
Location: New Orleans
Boat: We have a problem... A serious addiction issue.
Posts: 3,940
Re: moody 44 1995 Keel Bolts

Quote:
Originally Posted by noelex 77 View Post
The tensile and yield strength of steel and stainless steel is generally resonably similar, but does vary considerably with the different grades.
Noelex,

This isn't really true. Here are some numbers...

........................Tensile............yield

316.....................84ksi...............30ksi
Grade 5 Titanium.130ksi.............120ksi
Aqualoy..............100ksi..............37ksi
C65500................92ksi..............55ksi
2205 duplex.........90ksi...............60ksi

So while the tensile strength is similar for 316 as compared to the 2205, the yield strength (the point at which it distorts) is not. On a highly engineered part, the only reasonable thing is to only replace a part with something that is either identacle to what was there, something better in all significant ways, or to reengineer the part to ensure it will withstand the loads.
__________________
Greg

- If animals weren't meant to be eaten then they wouldn't be made of food.
Stumble is offline   Reply With Quote
Old 27-06-2012, 01:06   #13
Moderator
 
noelex 77's Avatar

Cruisers Forum Supporter

Join Date: Jul 2007
Location: Living on dirt waiting for our new yacht to be built.
Boat: Half built Bestevaer.
Posts: 10,618
Re: moody 44 1995 Keel Bolts

Quote:
Originally Posted by Stumble View Post
Noelex,

This isn't really true. Here are some numbers...

........................Tensile............yield

316.....................84ksi...............30ksi
Grade 5 Titanium.130ksi.............120ksi
Aqualoy..............100ksi..............37ksi
C65500................92ksi..............55ksi
2205 duplex.........90ksi...............60ksi

So while the tensile strength is similar for 316 as compared to the 2205, the yield strength (the point at which it distorts) is not. On a highly engineered part, the only reasonable thing is to only replace a part with something that is either identacle to what was there, something better in all significant ways, or to reengineer the part to ensure it will withstand the loads.
I think you are misreading my post.
I was comparing carbon steel with stainless steel in response to bstreep comments that SS is not as strong as carbon steel.
You have quoted the tensile and yield strength of various stainless steels, titanium and bronze

Anyway it's great to see your company is providing engineering advice to replace 316 and 304 stainless steel with something that will last the life of the boat. For just a few dollars more boat manufacturers could do this in the first place.
__________________
noelex 77 is offline   Reply With Quote
Old 27-06-2012, 09:04   #14
Senior Cruiser

Cruisers Forum Supporter

Join Date: Aug 2009
Location: between the devil and the deep blue sea
Boat: a sailing boat
Posts: 17,314
Re: moody 44 1995 Keel Bolts

I had a piece of corroded chain here. Very, very corroded. 10 mm material.

I had to cut it. Grabbed an angle grinder ... Inside, the material was pristine - full 9.99 mm of it.

I assume there is some time-exposure related factor in how much such steel corrodes. The cleaned part looks actually - clean.

I would undo some of the nuts while on dry and see how things look like around there.

b.
__________________
barnakiel is offline   Reply With Quote
Old 27-06-2012, 10:00   #15
Resin Head
 
minaret's Avatar

Cruisers Forum Supporter

Join Date: Aug 2007
Location: Seattle WA
Boat: Nauticat
Posts: 7,199
Images: 52
Re: moody 44 1995 Keel Bolts

You can use ultrasound, x-ray radiography, or magnetic particle flaw detection to check the condition of keel bolts without removing them. This will tell you if you have corrosion anywhere in the bolts that you can't see. For a bigger boat it is much cheaper than dropping the keel for visual inspection, and more reliable.
__________________

__________________
minaret is offline   Reply With Quote
Reply

Tags
keel

Thread Tools
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




Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 03:43.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.