Cruisers Forum

Join CruisersForum Today

Thread Tools Rate Thread Display Modes
Old 04-03-2012, 19:37   #1
Registered User
rotorman's Avatar

Join Date: Sep 2011
Location: Lombok, Indonesia
Boat: Amel Euros 41
Posts: 51
Rust from Screws of Rubber Fender

I have an extruded rubber fender around my boat. Is is slided on onto a flange and hold in place by wood screws from the top and bottom.

Originally I was using 316 ss screws. After a few years (and a lot of offshore sailing) the screws started to bleed rust. Especially near the lowest area of the fender where water can accumulate. I assume this is happening because there is no oxigen where the screws enter the rubber.

I replaced the screws on one side with silicon bronze screws. Now there is some bronz powder around the bolt heads but no major (yet). And it does not look very nice.

I am concerned that with the bronze screws it won't be much better than with the stainless ones.

Any suggestions?


rotorman is offline   Reply With Quote
Old 04-03-2012, 23:16   #2
Senior Cruiser
delmarrey's Avatar

Cruisers Forum Supporter

Join Date: Mar 2003
Location: Somewhere along the US West Coast
Boat: Modified Choate 40
Posts: 10,474
Images: 122
Re: Rust from Screws of Rubber Fender

Normally rub rails cover hull joints and have aluminum rivets in them. Don't know if this is what you have but on a 40'+ boat I'm surprised that it has a rubrail set up. I would think it would have a lap joint with a toerail/caprail.

Need more detail or pictures.

Faithful are the Wounds of a Friend, but the Kisses of the Enemy are Deceitful!
A nation of sheep breeds a government of wolves!

Take nothing but pictures, leave nothing but footprints!
delmarrey is offline   Reply With Quote
Old 05-03-2012, 00:10   #3
Registered User
rotorman's Avatar

Join Date: Sep 2011
Location: Lombok, Indonesia
Boat: Amel Euros 41
Posts: 51
Re: Rust from Screws of Rubber Fender

Hi. This is an Amel. Amels don't have traditional hull to deck joins. There is a fiberglass flange on the side just below the deck level which holds an U shaped heavy duty rubber. The flange can also act as a sacrifical energy absorver in case of an impact from the side.
So the only purpose of the screws is to hold the rubber (and they are not related to a hull to deck join).
I guess my real question is what material should I choose for the screws. Stainless (316) seems to bleed rust but only after a while. Bronze turns green immediately and there is green powder around the screws on the rubber.
rotorman is offline   Reply With Quote
Old 05-03-2012, 00:28   #4
Registered User
Shanaly's Avatar

Join Date: Oct 2010
Location: Perth west australia, Indian Ocean
Boat: Samson C-Falcon 41'9" composite ketch (designed by Cece Norris)
Posts: 226
Re: Rust from Screws of Rubber Fender

1 are you sure fixings are not brass? i have some which is powdering - acting as a sacrificial anode (to bronze fittings in this case - but once moist they can electrically link to any other metal including nobler ones like bronze which are linked by the 'moist circuit' ). iac you should try wiring your fixings to your yacht's common ground point (earth) - see Nigel Calder's Electrical and Mechanical 'bible' - which just means earthing with a conductive wire each screw to your engine block or other CGP.
2 yep ss needs lots of flow of oxygen to stay ss !!! but a fix is to use phosphoric acid - just paint on and leave. this turns any rust into a beneficial/benign metal compound after an hour or so - so no more bleeding. if you can get in there to scrub, you can make it shiny again too! hope this helps.
Shanaly is offline   Reply With Quote


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
Why Use Flat Webbing as Jacklines Instead of Rope ? Snore Deck hardware: Rigging, Sails & Hoisting 127 21-04-2012 06:53
Crew Wanted: Islands of Atlantic France & Rias of Spain RogerLloyd Crew Archives 1 19-03-2012 06:08
Not New but Never Said Hello ! Hi from the Mitten ! appick Meets & Greets 4 08-03-2012 08:03
Rust from Screws of Rubber Fender rotorman Construction, Maintenance & Refit 3 05-03-2012 00:28
Cruising to Sea of Cortez ... masallah 007 Destinations 1 04-03-2012 17:15

Our Communities

Our communities encompass many different hobbies and interests, but each one is built on friendly, intelligent membership.

» More about our Communities

Automotive Communities

Our Automotive communities encompass many different makes and models. From U.S. domestics to European Saloons.

» More about our Automotive Communities

Marine Communities

Our Marine websites focus on Cruising and Sailing Vessels, including forums and the largest cruising Wiki project on the web today.

» More about our Marine Communities

Copyright 2002-2015 Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 13:06.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2016, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2016, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.