There is an extensive discussion of corrosion on the AI at
Here is a quote from me regarding what I think is a fundamental problem w/ the AI regarding corrosion.
Galvanic corrosion is an electrolytic process, i.e., it occurs via transmission of electrons through the metal. The corrosion will occur anywhere on the aluminum surface where it makes contact w/ the saltwater. Here is a quote from Michael Kasten's web site: Aluminum is very active galvanically and will sacrifice itself to any other metal it contacts either directly or indirectly. Aluminum is anodic to everything except zinc and magnesium, and must be electrically isolated from other metals. (Kasten Marine Design, Inc.) As Kasten says, aluminum...will sacrifice itself to any other metal it contacts...even indirectly--that is, they do not have to touch. All they need for the aluminum to corrode (sacrifice) is to have a metal or wire connecting the aluminum to the other metal (steel, for example.)
The consequence of this for the Hobie AI is that a steel pin in the hinge will cause the aluminum bars to corrode anywhere the sea water touches the aluminum. Painting the aluminum is an attempt to reduce contact with saltwater, but any scratch or nick in the paint will start the galvanic corrosion process.
Zinc and magnesium are the only metals which sacrifice themselves in contact with aluminum. That is why I have added a zinc anode to each xbar. Zinc anodes can be purchased at most general marine stores (West Marine in the USA).
I have had no problem w/ my Mirage Drive. I wash it thoroughly w/ fresh water, let it dry for a couple days, and then spray all exposed metal parts w/ "Break Free" aersol spray lubrication. Break Free is recommended by RoadRunner elsewhere on this forum.
Hobie has been quite helpful w/ my aka/xbar corrosion problems. Nevertheless, I have installed 4 saucer-shaped zinc anodes--2 on the front xbar and 1 each on the rear braced akas. It was not possible to place the anodes on the rear xbar because the hull is wider in the rear. However, I do have a pencil anode in the 3/8" hole of the rear xbar. Here are the pictures.
The pencil anode is rather delicate (easily broken off), but it has survived a couple trips.
I'm sure this is "anode overkill," but, given my corrosion problems, I am hoping this fix will work. I will know by next year.