Anode to protect rigging? :: Catamaran Sailboats at TheBeachcats.com

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Anode to protect rigging?

rehmbo

Rank: Mate

Registered: Apr 27, 2011

Last visit: Dec 13, 2022

Posts: 163
Posted: Apr 29, 2013 - 05:27 AM

Anyone tried this? I'm normally a fresh water sailor, but the few times I've sailed in salt, I've noticed a little-bit of corrosion developing despite rinsing the boat off, etc.

Since Aluminum is further down the galvanic series relative to SS, I thought some small zinc anodes connected to the cross bars and mast might be effective. What do you think? Total waste of time?

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Jeff R
'88 H18 "Jolly Mon"
'10 C2 USA1193
NE IN / SE MI
cramsailing.com
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carolinacatamarans

Rank: Lubber

Registered: Apr 10, 2013

Last visit: Oct 25, 2015

Posts: 94
Posted: Apr 29, 2013 - 06:06 AM

rehmbo Total waste of time?

This IMO
MN3

Rank: Master Chief

Registered: Jun 20, 2006

Last visit: Apr 06, 2024

Posts: 7088
Posted: Apr 29, 2013 - 08:37 AM

i have thought about it too...

I certainly wouldn't worry if you sail mostly in fresh water... still unsure if it's worth drilling holes in a spar...

I do think it makes for a great band name

Tonight, performing at Roseland's Ballroom: Galvanic Corrosion and the Sacrificial Anode
PurdueZach

Rank: Mate

Registered: Apr 24, 2011

Last visit: Mar 20, 2018

Posts: 177
Posted: Apr 29, 2013 - 08:55 AM

Don't sacrificial anodes work under the basis that the material to be protected is submerged in a medium that allows current to pass- aka water? Anodes are generally placed underneath the hulls because they are constantly submerged in water and water is a good conductor. The mast and rigging on our beachcats are usually above the water (we hope) and air is a poor conductor.

Wikipedia - Galvanic Anode:

QuoteCathodic protection works by introducing another metal (the galvanic anode) with a much more anodic surface, so that all the current will flow from the introduced anode and the metal to be protected becomes cathodic in comparison to the anode. This effectively stops the oxidation reactions on the metal surface by transferring them to the galvanic anode, which will be sacrificed in favour of the structure under protection.

For this to work there must be an electron pathway between the anode and the metal to be protected (e.g., a wire or direct contact) and an ion pathway between both the oxidizing agent (e.g., water or moist soil) and the anode, and the oxidizing agent and the metal to be protected, thus forming a closed circuit; therefore simply bolting a piece of active metal such as zinc to a less active metal, such as mild steel, in air (a poor conductor and therefore no closed circuit) will not furnish any protection.

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-Zach
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rehmbo

Rank: Mate

Registered: Apr 27, 2011

Last visit: Dec 13, 2022

Posts: 163
Posted: Apr 29, 2013 - 10:17 AM

Zach - you have a point. I was thinking about that - no electrolyte to complete the electrical circuit except perhaps when it rains and the remaining salt residue gets re-hydrated.

Therefore, Mr. Carolina probably has the right answer: Waste of time.

Still hate to see the little spots of corrosion though. I think the worst offense came when I towed the boat home from Tradewinds in January. At about the Michigan border it started snowing. So nice of MDOT to put down 1/2 inch of salt for the 1 inch of snow we got . Tried rinsing all that off too, but you can't get it all.

--
Jeff R
'88 H18 "Jolly Mon"
'10 C2 USA1193
NE IN / SE MI
cramsailing.com
--