Anode advice

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shade2u2
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Anode advice

Postby shade2u2 » Wed Apr 05, 2017 3:37 pm

I have removed my anodes to clean up and reinstall. I would like some opinions regarding their condition.
The rudder has a small corrosion spot at the top corner. I'm going the grind that spot and paint in with 2000E.
My keel and trim tabs look good to me.
The following are pictures of the trim tab anodes that I plan to clean up and reinstall. The top anode has been cleaned a little. The bottom shows the corrosion on the tab contact side. What are your thoughts? What if I added another?
Attachments
TrimTab1.JPG
John
1984 28 Express Hardtop w/single 360 1.5:1 reduction drive

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shade2u2
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Re: Anode advice

Postby shade2u2 » Wed Apr 05, 2017 3:42 pm

This is the Keel & anodes.... How much life do you think that they have?
Should I drill a hole in the center for another contact point?
There are 4 of these. The other 2 are in much better shape. They must be newer.
Attachments
KeelAnode.jpg
John
1984 28 Express Hardtop w/single 360 1.5:1 reduction drive

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Maestro
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Re: Anode advice

Postby Maestro » Wed Apr 05, 2017 4:55 pm

They look a little rough but if you cleaned them off with a stiff stainless wire brush they would probably still have some life left to them. Additional contact points cant hurt.

The general rule is that anodes are dead after 50% or more of their original material has worn away.

If you decide to go with new ones, here's a link to the Marinette anodes on boatzincs.com. It's one of the best places to get anodes. Good prices.
http://www.boatzincs.com/marinette-bar.html

For a 28' BigM , 1 of those 3-foot strips on each side of the keel is good. There should also be small anodes on the rudder(s) and trim tabs.
Maestro
1970 28' Express
Single Chrysler 440
Mississippi River

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shade2u2
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Re: Anode advice

Postby shade2u2 » Wed Apr 05, 2017 5:32 pm

Thank you for the info. My hull looks good and I just want to keep it that way.
I've got 42" of anode on each side of the keel.
The 12" ones in the 1st picture are from the tabs. I may ad more since those are a little rough. They seem to be doing their job as the tabs look good.
My rudder has a 3.5" round anode that's still good.

The cleaned up anodes.
John
1984 28 Express Hardtop w/single 360 1.5:1 reduction drive

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bcassedy
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Re: Anode advice

Postby bcassedy » Wed Apr 05, 2017 7:12 pm

John,

It is possible to have too much anode protection. I'd recommend going with the specs from BoatZincs.com. Also, I have 36" on the keel of my boat (1 36" on each side). I've attached them with 4 SS bolts, washers and lock nuts. There's no way to keep the 2 surfaces from collecting a layer of gunk over the season but the 4 attach points seem to ensure a good interaction between the keel and anodes.

Bill
Bill & Sharon Cassedy
"Sunset Seeker"
'88 32' Sedan Bridge
Located in Aurora, In.
Twin 318cu in Chrysler
1.5:1 Velvet drive trannies
Fresh water only

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shade2u2
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Re: Anode advice

Postby shade2u2 » Wed Apr 05, 2017 8:03 pm

Thank you Bill. I won't go over board with anodes then. Seeing that my hull looks good along with the tabs, I should accept that they're doing their job. It looks like I don't need more holes drilled through the keel - which just sounds right...
I'll get things cleaned up well for good contact when I reinstall. That was my plan to begin with.
Here are the cleaned up anodes...
Attachments
CleanedAnodesx.jpg
John
1984 28 Express Hardtop w/single 360 1.5:1 reduction drive

jralbert
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Re: Anode advice

Postby jralbert » Thu Apr 06, 2017 1:24 am

You're on the right path. Anodes are not worn past 50% (and recall that when mine did get worn, I put two worn ones together to equal one solid one. I don't think you need to drill more holes. Clean the keel behind the anodes (no paint) and bend them outward just a tad so when you tighten the bolts the anode to keel contact is firm. Done and protected.

(nice set of easy to follow pix)

Just reemembered that I have leftover zincs. Some new, some partly worn. Must inventory and put up for sale here. String around finger
-joel-
former owner 1988 '32 FB Sedan
Chesapeake Bay
twin 318 / 240 hp
Potomac MD

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shade2u2
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Re: Anode advice

Postby shade2u2 » Thu Apr 06, 2017 5:51 am

Thank you Joel
John
1984 28 Express Hardtop w/single 360 1.5:1 reduction drive

Fastjeff
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Re: Anode advice

Postby Fastjeff » Fri Apr 07, 2017 5:55 am

Agreed with the following comment: What does your CAPAC say? That should be your guide as to having "too much" anodes on there or not enough.

My old boat (fairly fresh water) needed the usual mag-alum units plus a block of magnesium on the trim tab to keep the CAPAC readings in mid-range.

Jeff
"We live at the bottom of an ocean of air, not at the top." General Marvage Slatington

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shade2u2
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Re: Anode advice

Postby shade2u2 » Fri Apr 07, 2017 8:18 am

My capac usually read about .78 - .88 if I remember right. I'm in fresh river water.
How would you know that you have "too much" anodes? What's the downside?
So Magnesium anodes on the trim tab would be okay?
thanx Jeff
John
1984 28 Express Hardtop w/single 360 1.5:1 reduction drive