What should the Galvanic meter readings range between?

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oef0102
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What should the Galvanic meter readings range between?

Postby oef0102 » Thu Sep 13, 2018 12:39 pm

I recently purchased a 1975 28' Marinette that has a galvanic meter installed on the dashboard.
Asking what the reading should be to be considered in a safe zone? Trying to find out specifically when I need to replace the anodes.
Thank you

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bill
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Re: What should the Galvanic meter readings range between?

Postby bill » Thu Sep 13, 2018 1:05 pm

BigM
Your meter should tell the acceptable ranges. Look at the fine print for aluminum. ;)

Table 1. Galvanic Series Of Metals In Sea Water With Reference To Silver/Silver Chloride Reference Cell [Sea water flowing at 8 to 13 ft./sec. temperature range 50 degree F (10 degree C) to 80 degree F (26.7 degree C)]

Anodic or Least Noble Corrosion Potential Range in Millivolts
*The range shown does not include sacrificial aluminum anodes. Aluminum alloy sacrificial anodes are available that have a maximum corrosion potential of -1100 mV.
Magnesium and Magnesium Alloys -1600 to -1630
Zinc -980 to -1030
Aluminum Alloys -760 to -1000
Cadmium -700 to -730
Mild Steel -600 to -710

bill
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ALUMINATION
Grosse Ile MI
Located on LakeErie
37' F/B Sedan
1975
Twin 360 Chrysler Marine
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barkleydave
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Re: What should the Galvanic meter readings range between?

Postby barkleydave » Fri Sep 14, 2018 9:14 am

Ideal range:
.95-1.05

numbers will vary depending on water clarity and wether fresh or salt water.

safe boating,
Dave
1987 Marinette 29 FB Sedan
Retired Boat Accident UL and USCG trained investigator
Retired USCG Captain

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shade2u2
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Re: What should the Galvanic meter readings range between?

Postby shade2u2 » Fri Sep 14, 2018 10:29 am

Mine reads .85 - .92 most of the time now. How much of a concern is this?
I added a cabled anode but it doesn't seem to change the readings. I may not have a good connection with the clip.
John
1986 39 Sedan w/Crusader 454 & 1.92 drive.
1984 28 Express Hardtop FOR SALE
w/single 360 1.5:1 drive
Ohio and Muskingum Rivers (Marietta, OH)

jralbert
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Re: What should the Galvanic meter readings range between?

Postby jralbert » Fri Sep 14, 2018 10:16 pm

shade2u2 wrote:Mine reads .85 - .92 most of the time now. How much of a concern is this? I added a cabled anode but it doesn't seem to change the readings.
If you haven't done so already, clean the wire connections on the meter and see if that makes a difference. It may since the current amounts are so small to begin with. Meanwhile, imho, your readings seem pretty close to the listed range
-joel-
former owner 1988 '32 FB Sedan
Chesapeake Bay
twin 318 / 240 hp
Potomac MD