Corrosion beetween carbon mast and (cast iron ?) mast base

Hello,

I just bought a hobie 20 in France, in really good shape.
It was in a barn since 7 years ! So it camed for avery good price

I have an issue with the mast, it's a carbon mast and the mast base is alomst completly "eat" by the corrosion,
The mother's owner tell me about this issue. But have absolutely no idea on how to fix it...

First I need to find a new mast base. I don't find any of it in Europe. I'm hobie 17 sailor and it seems to be exactly the same (ref 17000020)
Can somone confirmed if i'm right ? And did somone knows the composition of this piece ?

And then I need to fix this issue. Do you know how this reaction is possible ? And how it works ? Because I search on internet and don't find anything about it...

Did anyone face the same issue has me ? And do you solved it ?

Thanks, Emile

I know on a bike if you put an aluminum seat post into a carbon frame bike it is recommended to put something like galvanic coating grease on the aluminum tube because of the corrosion or galvanic reaction. Around salt water probably promotes the condition.

Correct - aluminum and carbon don’t go well together (galvanically). Aluminum acts as the anode and will be erroded, which sounds like what happened here. As far as I know, the Hobie 20 uses the same mast base as the 17, so I would check with a Hobie dealer if replacement parts are still available. As mentioned above, it would be good to put a corrosion barrier between the aluminum and carbon parts when you re-assemble. Either a corrosion inhibiting paste (like Tefgel) or a bead of thickened epoxy.

By the way, the Hobie 20 came stock from Hobie with an aluminum mast. Sounds like your boat came with a custom carbon mast - nice upgrade!

sm

Thanks for your replies, i know now how this work !
I do have find hobie 17 mast base but not 20... strange...
I'll look forward for other solutions to prevent corrosion and let you know what I ll do.

Yeah, it was a racing one, the boom and the stick are also in carbon !

Zinc anode?

Hello, after a few search, i'll use "LanoCote" gel and I'll put a zinc anode to prevent the aluminium reaction,
I'll also remove the pop rivet once a year (at least) to clean the bottom part with clear water and to check the state of both the gel and the anode
thanks to all of you !

Emile,
Hobie 17 and Hobie 20 mast base are identical - USA Part Number 50416011 - it is an aluminum alloy casting
Cheers

_________________
1984 H16 "Mister Rogers"
1984 H14 "Sundays"
2000 H20 "Jet"
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