What should the Galvanic meter readings range between?

Things that are of general interest.
Post Reply
oef0102
New poster
Posts: 7
Joined: Wed Sep 12, 2018 11:11 am

What should the Galvanic meter readings range between?

Post by oef0102 »

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
User avatar
bill
Royal Aluminum Star
Posts: 520
Joined: Sat Jul 12, 2014 7:17 am
Location: Grosse Ile MI

Re: What should the Galvanic meter readings range between?

Post by bill »

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
Please use a signature when you post. :D
Former owner of
ALUMINATION
Grosse Ile MI
Located on LakeErie
37' F/B Sedan
1975
Twin 360 Chrysler Marine
Raw water cooled
Hydraulic steering both helms
USCG Master Lic. Retired[/color]
Third Owner bill
barkleydave
Site Admin
Posts: 410
Joined: Sat Jul 12, 2014 6:18 am
Location: Kentucky

Re: What should the Galvanic meter readings range between?

Post by barkleydave »

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
User avatar
shade2u2
Royal Aluminum Star
Posts: 290
Joined: Mon Jul 21, 2014 3:11 pm
Location: Marietta, Ohio -mile marker 172

Re: What should the Galvanic meter readings range between?

Post by shade2u2 »

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.
former - '84 28 Express Hardtop w/single 360 1.5:1 drive (SOLD - now in Uruguay)
Ohio and Muskingum Rivers (Marietta, OH)
jralbert
Site Admin
Posts: 885
Joined: Fri Jul 11, 2014 9:15 pm

Re: What should the Galvanic meter readings range between?

Post by jralbert »

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
Post Reply