New Sails for F-25?

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GeoffSchultz
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Re: New Sails for F-25?

Post by GeoffSchultz »

Aluminum rivets probably pose some corrosion risk, but I wonder if the mast is grounded, then the corrosion ends up in the zincs, and all is well (zinc is below aluminum on the series).
Please correct me if I'm wrong, but I don't think that grounding an object will change the corrosion. Basically you have a chemical reaction between the two dissimilar metals which is creating an electrical current which is eroding one of the surfaces. Now, if both of them were grounded, you might not get the corrosion...

I certainly have locations where I have corrosion between a stainless part and my aluminum toe-rail, which is well grounded. Applying an anti-corrosive coating between the surfaces, such as Tef-Gel, will greatly reduce the corrosion.

-- Geoff
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1997 Freedom 40/40
http://www.GeoffSchultz.org

bearb4tree
Posts: 16
Joined: Tue Apr 28, 2009 11:10 pm
Location: San Franciso Bay

Re: New Sails for F-25?

Post by bearb4tree »

Gang,

I probably should have said "connected" instead of "grounded", but I am wondering if the mast serves more like a conductor than a cathode, and the real battery is between the zincs (I don't even know where they are) and the aluminum. This would make the aluminum the cathode and the zinc the anode. I'll have to look at the boat more. Also this could be completely wrong, perhaps the mast is insulated in some way.

I went to Pineapple sails in Alameda and they gave me an A108 sail slide from Bainbridge to test in my track. They also took a look at the wear on my broken sail slide and said it was abnormal, the wear pattern suggests the "offset" is wrong and that the halyard is pulling the sail up at the wrong angle. Since the halyard is not chaffed, it probably means the slides have been replaced and the offset changed, this means the halyard exerts too much tension on the track as it goes up. Sounds suspicious. I will have the sail off the boat and into them to look at.

I'll post again when I have some progress.

Thanks to everyone for the advice and help!

Matt

Hull F25 #216
SF Bay

bearb4tree
Posts: 16
Joined: Tue Apr 28, 2009 11:10 pm
Location: San Franciso Bay

Re: New Sails for F-25?

Post by bearb4tree »

Hi All,

I had new sail slide sewn on (Bainbridge A107, not A108 as in a previous post). This helped a lot, thanks to Tricia for the suggestion.

Cheers,

Matt
Hull #216

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