zinc adnodes on AIs

With all the talk of the corrosion proplems on the older AI akas, I was thinking it would be a prime situation for adding a small zinc adnode to each of the akas. Thoughts? I checked into small ones at West Marine and they have little round ones you can attach with a single bolt. Think I'm going to ad them to mine. It can't hurt. Scott I know you mentioned keeping it lubed and check it periodically. I talked to the guy at the store and he said that's what they are designed to prevent.

I think the zincs will only help if there is constant metal to seawater contact. 
 the only metal on the Akas is the bracket on top right?
For the zinc to work properly it has to be attached to "grounded" metal below the waterline.
 
I dont think the corrosion is from electrolysis. 

It is from electrolysis. They used brass inserts with S/S and aluminum. The opposing metals in the salt set it up for corrosion.

Wouldn't hurt.  Not really required unless you are running power through the yak and you leave it in S.W. for extended periods of time.  However, it can't hurt.  The zinc needs to be underwater, however.  From what I see on my yak, the metal isn't under water all the time= ineffective.

Under water. Huh! good to know. It is soaked most of the time your sailing tho. That's why I posted this. All the input helps.

Zincs left in "open air" will crust over and become ineffective.  For trailered boats it's always good to wire brush the zinc before launching to "re-activate" it.

It is from electrolysis. They used brass inserts with S/S and aluminum. The opposing metals in the salt set it up for corrosion.

 Yes, You're exactly right... "corrosion" from dis-similar metals in contact.  Not electrolysis from electrical current.
If the inserts are plugged into plastic there will not be any electrical current flowing thru. If the zinc is attached to the plastic on the bottom of the Aka it wont give satisfactory results. Well it might if you ran a ground/ bonding wire from the zinc to every piece of metal on the AI.
Zincs work when bolted to metal parts that are submersed under water.
 The taking apart and applying anti-seieze/ and keeping covered  under a film of grease... I think... is your best option of keeping the corrosion down to a minimum.

Anodes were suggested on the Hobie Forum. Here is a discussion from this year.
http://www.hobiecat.com/forums/viewtopic.php?f=75&t=42283&hilit=aka+bar+corrosion
 
I built my AI 8 months ago and greased the bottom of the aka feet with marine grease. Yesterday I pulled and cleaned the aka bars. There was the beginning of corrosion on 2 of the 8 bolt holes. Not nearly as bad as other posted pictures so I think the grease helped retard the corrosion process. The 2 bolt holes with corrosion sat on brass inserts which projected slightly above the plastic deck as mentioned on the Hobie thread and the brass to aluminum contact is the source of the corrosion. To remediate this, I used a Dremel and ground down the brass insert. The I painted finger nail polish on all of the brass inserts and around the bottom of the aka bar bolt holes. Then put a thick coat of marine grease on and put it back together. We did the same thing to John's AI but didnt grind down the brass inserts. Will post up next year if it worked.

Have you considered a nylon washer instead of grinding it down?

seems like a nylon washer would raise it up off the hull and now focus the weight bearing surface from the entire pad touching the hull to just the nylon washer surfaces.  Other option might be a thin nylon film/sheet or possibly a rubber dip coating to the underside of the feet (ie that stuff they sell for tool handles) ?  Another thought

You should be able to coat the threads with anti-seize to fix the issue with using dissimilar metals

That's basically what Scott did with the marine grease.

I considered using either nylon or SS washers and I believe it would prevent corrosion because it would prevent the brass from contacting the aluminum. The SS aluminum contact does not accelerate corrosion. The reason I didn't go this route yet is:
#1 It would concentrate the load to the area of the washers instead of the area of the whole foot. You could lay out more washers to distribute the load, however.
#2 It would create more of a gap for water entrapment.
#3 If the hull cracked underneath the feet, Hobie probably would not honor the warranty because of the mod.

All that said, it is my plan B for this year.

Scott,  rather than the nylon washer, since I share the same worries over load distribution, I'd consider a nylon film/sheet cut to the same size as the foot.  If thin enough, it won't raise the rigger foot height, it will eliminate the concern over load bearing surface area and should still prevent the brass to aluminum contact.  My only concern, which you have already eliminated, would be for those of us whose brass inserts protrude which could weare thru a thin film, possibly.

Good ideas everyone...

Well it's been over a year and pulled the aka bars for inspection. All in all they looked about the same, so I think the finger nail polish and marine grease prevented the corrosion process.