Rudder head corrosion - 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 01-17-2003
Senior Member
 
Join Date: Dec 2002
Posts: 140
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 12
aflanigan is on a distinguished road
Rudder head corrosion

The rudder head on my Helms 24 which is presumably aluminum alloy exhibits pitting corrosion at its lower edges, presumably below the water line. I recall reading that aluminum doesn''t do well submerged because it cannot form a protective oxide coating like exposed aluminum. I guess this is why the bottom part is corroded (and underneath the stainless steel straps of the pintle bolted to the sides of the rudder head, there is also a whitish powdery crud).

I am wondering if a zinc chromate primer would be a good barrier coating to prevent any further corrosion on the rudder head. I have disassembled it and wire brushed down to bare metal as well as I could. Any thoughts?
Reply With Quote Share with Facebook
  #2  
Old 01-17-2003
DelmarRey's Avatar
Senior Member
 
Join Date: Aug 2001
Posts: 258
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 14
DelmarRey is on a distinguished road
Rudder head corrosion

My suggestion would be to sandblast the affected areas, fare them in with epoxy with a filler, then paint with epoxy paint as far up as need be to keep it out of the water. And the same under the SS pintles. Tape off an area around the pintles and paint under them. SS tends to speed up the corrosion process when mated to aluminum (electrolysis). Or you could just paint the whole rudder in epoxy, If you want to go that far................Del
Reply With Quote Share with Facebook
  #3  
Old 01-18-2003
Member
 
Join Date: Dec 2002
Posts: 43
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
peterpan2k is on a distinguished road
Rudder head corrosion

You might considder bonding this to your zink when you get it repaired to stop further loss.
Jim
Reply With Quote Share with Facebook
  #4  
Old 01-27-2003
Senior Member
 
Join Date: Dec 2002
Posts: 552
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 12
GordMay is on a distinguished road
Rudder head corrosion

Zinc Chromate primer will not provide an effective barrier between the Aluminum and Stainless (as you note,neither of which do well under water); but Del''s advice presents a good start.
Even better would be a nylon sleeve, separating the dissimilar metals (perhaps not practical?).
Further to peterpan2k, If the pintle fastenings are accessable from the inside, bond them and the rudder shaft, if possible, (using a shaft brush) to the ground bus.
Reply With Quote Share with Facebook
Reply


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
Building a New Ruuder Armchairprotest Gear & Maintenance 16 12-06-2009 10:15 PM
Building a Rudder Newport 30 Armchairprotest Gear & Maintenance 5 04-07-2009 01:11 PM
Rudder anode question aflanigan Gear & Maintenance 2 01-03-2004 12:25 PM
Maintaining head to wind jbr Learning to Sail 11 08-18-2003 01:30 PM
cracked rudder aasault Gear & Maintenance 0 10-10-2001 03:30 PM


All times are GMT -4. The time now is 05:34 AM.

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.