Understanding the CAPAC

jralbert
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Re: Understanding the CAPAC

Postby jralbert » Tue Feb 07, 2017 4:16 pm

thank god it's posted for all the world to see and I don't have to plow through that project again :-
:twisted:
But most important, happy to get the info out for all the fine boaters on this board
-joel-
former owner 1988 '32 FB Sedan
Chesapeake Bay
twin 318 / 240 hp
Potomac MD

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bcassedy
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Re: Understanding the CAPAC

Postby bcassedy » Wed Feb 08, 2017 12:00 am

As (un)luck would have it, the silver oxide portion of my unit fell off sometime during last season. I discovered this just after haulout in October. Had found Ward's Marine last week to check on replacement.

Got a call from.their tech who advised the whole "pie pan" thru hull unit has to be purchased (item - 37800). Cost is hideous - $747.18!!!

Think it's time to use a homemade unit. Just can't justify that kind of exhorbitant expense. :-(

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

carl
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Re: Understanding the CAPAC

Postby carl » Wed Feb 08, 2017 1:23 am

BigM
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MetalHead
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Re: Understanding the CAPAC

Postby MetalHead » Wed Feb 08, 2017 5:38 am

Email me the PDF and I will also look into why we cant post them to the forum.

cvmikeray@yahoo.com
1959 Family Cruiser - Sold - Gary Dick - 12/05/14
1963 Express 31x10 - Sold - Joe & Ginger Tabor - 01/21/2017
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Big BigM 's Rule !!!
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carl
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Re: Understanding the CAPAC

Postby carl » Wed Feb 08, 2017 6:09 am

BigM
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carl
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Re: Understanding the CAPAC

Postby carl » Fri Feb 10, 2017 1:04 pm

BigM
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carl
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Re: Understanding the CAPAC

Postby carl » Thu Mar 02, 2017 4:55 am

BigM
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Fastjeff
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Re: Understanding the CAPAC

Postby Fastjeff » Thu Mar 02, 2017 6:28 am

Yeah. I'd add a magnesium guppy to get the reading up a few points.

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

carl
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Re: Understanding the CAPAC

Postby carl » Thu Mar 02, 2017 6:35 am

BigM
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barkleydave
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Re: Understanding the CAPAC

Postby barkleydave » Thu Mar 02, 2017 9:24 am

Many folks spend way too much time pushing the CAPAC button.

First your numbers while they may be a bit low there are other factors to consider.

1. Early freshwater cold temps. will lower the reading.
Why you ask? Pure fresh water is actually an insulator and a very poor conductor. Electron flow is reduced thus your neg. readings often will be lower.

2. Initial submersion numbers often will be lower and slowly rise.

Most of us are using the aluminum strip anodes on keel, rudders, and trim tabs. By added an over the side Mag anode your numbers will increase and will take most if all of the galvanic load off the aluminum anodes. Use a SS. brush and clean your mag anode several times a season and insure you have a clean ground for the clip. Most clip the cable to a stanchion.

3. As fresh water warms up and there is more suspended sediment, algae etc. numbers will also rise since the contaminated water is a better conductor.

I do not recommend using mag. anode strips on our Marinette Yachts. Even in fresh water they will sacrifice too quickly and you may find it too hot. Long term readings of above 1.05 can cause damage as well,

4. Double check your shaft isolation. If it is not isolated it will pull numbers down and no amount of mag. will correct it but will make it worse.

Do not be too concerned about rudder shaft isolation. Properly barrier coating and paint will effectively isolate the rudder blades. Anodes on the rudders will also protect them. It is really non issue if you have more recent SS rudder shafts and blades. Also most our M's use the Nylon backing glands which isolate well.

safe boating,

dave

safe boating,

dave
1987 Marinette 29 FB Sedan
Retired Boat Accident UL and USCG trained investigator
Retired USCG Captain