Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 08-11-2011, 19:15   #1
Registered User

Join Date: Nov 2011
Location: Toronto
Boat: Catalina MK11 34'
Posts: 7
Help ! Coating on Prop Shaft

When I hauled my boat this fall (Lake Ontario - fresh water) I had a sandy coating on my shaft and prop. (See pictures). Can anyone please tell me what causes this ? It rubs off easily and leaves no apparent damage. No one else at our club has it. Someone suggested electrolysis but does electrolysis attract sand ? There is no pitting. I have slid the shaft back an inch and there is nothing in the cutlass bearing. This is the second year in a row.
Help. Please
Attached Thumbnails
Click image for larger version

Name:	PB050010.jpg
Views:	115
Size:	441.4 KB
ID:	33471   Click image for larger version

Name:	PB050011.jpg
Views:	110
Size:	448.6 KB
ID:	33472  

__________________

__________________
99Chances is offline   Reply With Quote
Old 08-11-2011, 19:24   #2
Registered User

Join Date: Nov 2011
Location: Toronto
Boat: Catalina MK11 34'
Posts: 7
Sandy Coating on Prop Shaft

When I hauled my boat this fall (Lake Ontario - fresh water) I had a sandy coating on my shaft and prop. (See pictures). Can anyone please tell me what causes this ? It rubs off easily and leaves no apparent damage. No one else at our club has it. Someone suggested electrolysis but does electrolysis attract sand ? There is no pitting. I have slid the shaft back an inch and there is nothing in the cutlass bearing. This is the second year in a row.
Help. Please
Attached Thumbnails
Click image for larger version

Name:	PB050010.jpg
Views:	92
Size:	441.4 KB
ID:	33473   Click image for larger version

Name:	PB050011.jpg
Views:	101
Size:	448.6 KB
ID:	33474  

__________________

__________________
99Chances is offline   Reply With Quote
Old 08-11-2011, 19:47   #3
cat herder, extreme blacksheep
 
zeehag's Avatar

Cruisers Forum Supporter

Join Date: Jul 2008
Location: furycame alley , tropics, mexico for now
Boat: 1976 FORMOSA yankee clipper 41
Posts: 17,777
Images: 56
Send a message via Yahoo to zeehag Send a message via Skype™ to zeehag
Re: Sandy coating on prop shaft

looks like dried marine slime.
zeehag is offline   Reply With Quote
Old 08-11-2011, 19:58   #4
Registered User
 
Sailor g's Avatar

Join Date: Jan 2011
Location: Southern California
Posts: 1,137
From what I remember from growing up in the area it might be snow! Could it be calcium or other mineral build up? Lots of minerals in the water around there?
__________________
Sailor g is offline   Reply With Quote
Old 08-11-2011, 20:03   #5
Registered User

Join Date: Nov 2011
Location: Toronto
Boat: Catalina MK11 34'
Posts: 7
Re: Sandy coating on prop shaft

Quote:
Originally Posted by zeehag View Post
looks like dried marine slime.
Right. That is what it looks like except when dry it is a sandy substance. And none of the other 120 boats have it. I'm afraid it is working its way up into to my dripless bearing.
__________________
99Chances is offline   Reply With Quote
Old 08-11-2011, 20:10   #6
cat herder, extreme blacksheep
 
zeehag's Avatar

Cruisers Forum Supporter

Join Date: Jul 2008
Location: furycame alley , tropics, mexico for now
Boat: 1976 FORMOSA yankee clipper 41
Posts: 17,777
Images: 56
Send a message via Yahoo to zeehag Send a message via Skype™ to zeehag
Re: Sandy coating on prop shaft

do you keep your boat in exactly the same place the others do?
zeehag is offline   Reply With Quote
Old 08-11-2011, 20:30   #7
Marine Service Provider
 
fstbttms's Avatar

Cruisers Forum Supporter

Join Date: Oct 2006
Location: Under a boat, in a marina, in the San Francisco Bay
Posts: 3,594
Re: Sandy coating on prop shaft

It is scale deposited by your anodes as they deplete.
__________________
fstbttms is offline   Reply With Quote
Old 08-11-2011, 20:32   #8
Marine Service Provider
 
fstbttms's Avatar

Cruisers Forum Supporter

Join Date: Oct 2006
Location: Under a boat, in a marina, in the San Francisco Bay
Posts: 3,594
Re: Help ! Coating on prop shaft

http://www.cruisersforum.com/forums/...tml#post813937
__________________
fstbttms is offline   Reply With Quote
Old 09-11-2011, 06:53   #9
Registered User

Join Date: Nov 2011
Location: Toronto
Boat: Catalina MK11 34'
Posts: 7
Re: Help ! Coating on Prop Shaft

The boat is kept in an assigned slip at a yacht club. No other boats have this deposit.
I know what it is; it's a gritty, sandy coating.
What I am looking for is to find out what is causing it; on only my shaft and prop.
__________________
99Chances is offline   Reply With Quote
Old 09-11-2011, 07:09   #10
Moderator Emeritus
 
GordMay's Avatar

Join Date: Mar 2003
Location: Thunder Bay, Ontario - 48-29N x 89-20W
Boat: (Cruiser Living On Dirt)
Posts: 31,592
Images: 240
Re: Help ! Coating on Prop Shaft

Greetings and welcome aboard the CF, 99Chances.

As fstbttms notes, it’s the result of the electrolytic corrosion of your zinc anode.
__________________
Gord May
"If you didn't have the time or money to do it right in the first place, when will you get the time/$ to fix it?"



GordMay is offline   Reply With Quote
Old 09-11-2011, 07:26   #11
Registered User

Join Date: Nov 2011
Location: Toronto
Boat: Catalina MK11 34'
Posts: 7
Re: Help ! Coating on Prop Shaft

I believe you are right. Thanks.
Now I need to find out why me and no one else?
I've had the boat batteries (cable, isolater,fuses etc.) rewired, a new charger and off switches. Could there be a problem there?
The guy who did the work is an electrical engineer and is meticulous. He tested for stray current. My anodes don't seem to be disappearing any faster than anyone elses.
And they don't get the sandy slime!
__________________
I already know what need to know about my fate. I will grow old and die.
Richard Boden - First you row a little boat.
99Chances is offline   Reply With Quote
Old 09-11-2011, 07:33   #12
Marine Service Provider
 
fstbttms's Avatar

Cruisers Forum Supporter

Join Date: Oct 2006
Location: Under a boat, in a marina, in the San Francisco Bay
Posts: 3,594
Re: Help ! Coating on Prop Shaft

This is not indicative of a problem and is a very common occurance. I wouldn't waste another second worrying about it.
__________________
fstbttms is offline   Reply With Quote
Old 09-11-2011, 07:43   #13
Registered User

Join Date: Nov 2011
Location: Toronto
Boat: Catalina MK11 34'
Posts: 7
Re: Help ! Coating on Prop Shaft

OK. Thanks Fstbttms.
The only reason I was even concerned was that the same sandy slime appeared to be getting to my Lasdrop dripless bearing and causing it to leak. Once wiped clen the drip would stop.
Just annoying. That's all. Thanks for your help. Appreciated.
__________________
99Chances is offline   Reply With Quote
Old 20-11-2011, 09:57   #14
Registered User
 
SabreKai's Avatar

Join Date: Sep 2008
Location: Toronto, Canada on Lake Ontario
Boat: Roberts Offshore 38
Posts: 1,287
Images: 5
Re: Help ! Coating on Prop Shaft

Not to worry mate, you aren't the only one. I'm at the bottom of Kipling Avenue at Lake Shore Yacht Club in Etobicoke, and I have the same stuff on my shaft as well. It comes off easily and there is no damage to the shaft.

As a matter of fact I pulled my shaft yesterday and between the gritty scale, slopped over bottom paint and some epoxy and other gunk, the only clean spots are where the prop was pulled, the area inside the cutless and the area under the stuffing box packing. Yuck.
__________________

__________________
SabreKai
SV Sabre Dance, Roberts Offshore 38
http://sabredancing.wordpress.com/
SabreKai is offline   Reply With Quote
Reply

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


Similar Threads
Thread Thread Starter Forum Replies Last Post
Prop Shaft Removal ppenoyar Propellers & Drive Systems 8 04-10-2011 02:33
Prop Shaft Spinning when Sailing bruadair Propellers & Drive Systems 73 01-09-2011 09:18
Prop Shaft Leaking STG Construction, Maintenance & Refit 20 08-08-2011 16:21



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 11:41.


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.