Reply
 
Thread Tools Search this Thread Display Modes
 
Old 12-25-2018, 04:42 PM   #1
Senior Member
 
jhance's Avatar
 
City: Eastsound
Country: USA
Vessel Name: Audrey Grace
Vessel Model: 2003 Camano 31
Join Date: Nov 2017
Posts: 122
Mixing aluminum and zinc anodes

Is there any harm in mixing the two? From what I am reading, it's OK to do. My boat is in salt water year-round (San Juan Islands, WA) and I have anodes on the transom, skeg, prop shaft, swim step struts, and bow thruster.
__________________
Advertisement

jhance is offline   Reply With Quote
Old 12-26-2018, 02:29 AM   #2
TF Site Team
 
Insequent's Avatar
 
City: Brisbane
Country: Australia
Vessel Name: Insequent
Vessel Model: Ocean Alexander 50 Mk I
Join Date: Mar 2012
Posts: 2,247
Well, the zinc ones will disappear first based on the galvanic potential. Then, if there is a distance between whatever you are trying to protect and the aluminum anodes you will get some corrosion. In short, IMO, it makes no sense at all to mix different anode types.
Attached Files
File Type: pdf Galvanic_Table.pdf (309.7 KB, 23 views)
__________________

__________________
Brian
Insequent is offline   Reply With Quote
Old 12-26-2018, 02:35 AM   #3
Guru
 
Comodave's Avatar
 
City: Au Gres, MI
Country: US
Vessel Name: Never Say Never
Vessel Model: President 41 DC
Join Date: Jul 2015
Posts: 4,155
No you should not mix them unless one type is in the engine and the other type is on the hull or shafts. With two types of anodes in the same body of water, one will erode faster and the other will not be protecting the boat. Stick with one type.
Comodave is offline   Reply With Quote
Old 12-26-2018, 06:26 AM   #4
TF Site Team
 
Bacchus's Avatar
 
City: Seneca Lake NY
Country: US
Vessel Name: Bacchus
Vessel Model: MS 34 HT Trawler
Join Date: Nov 2014
Posts: 2,661
Agree mixing not recommended if in the same electrical cell. Wondering where you have read its OK?
__________________
Don
2008 MS 34 HT Trawler
"Bacchus"
Bacchus is offline   Reply With Quote
Old 12-26-2018, 06:59 AM   #5
Senior Member
 
City: Green Cove Springs, Florida
Country: USA
Join Date: Feb 2012
Posts: 304
Send a message via Skype™ to bglad
It is a good question. Did some quick reading and from what I found the aluminum anodes are more active. If placed on the same circuit as zinc they will protect all the metals including the zinc. It makes sense that if the aluminum goes first zincs will kick in later. If the metals are not connected (bonded) to one another no harm is done they will protect whatever they are attached to.

When I do bonding checks propeller shafts usually have the highest resistance connection to bonding systems. Keeping an anode(s) on the prop would seem to be good insurance. If you put an aluminum there and zinc everywhere else it would be depleted more rapidly negating your efforts.

Aluminum has not caught on in the area I am located (brackish) possibly due to lack of local inventory. I find a lot of sleepy zinc on hulls. Most are caked with a layer of general corrosion.

Quote:
Originally Posted by jhance View Post
Is there any harm in mixing the two? From what I am reading, it's OK to do. My boat is in salt water year-round (San Juan Islands, WA) and I have anodes on the transom, skeg, prop shaft, swim step struts, and bow thruster.
bglad is offline   Reply With Quote
Old 12-26-2018, 09:21 AM   #6
Senior Member
 
Capecodder's Avatar
 
City: Cape Cod, MA or Fort Myers, FL
Country: USA
Vessel Name: Osprey
Vessel Model: Her Shine. Newburyport
Join Date: Dec 2013
Posts: 350
Corrosion: Buying, Owning and Maintaining Boats and Yachts
Capecodder is offline   Reply With Quote
Old 12-26-2018, 09:27 AM   #7
Senior Member
 
Capecodder's Avatar
 
City: Cape Cod, MA or Fort Myers, FL
Country: USA
Vessel Name: Osprey
Vessel Model: Her Shine. Newburyport
Join Date: Dec 2013
Posts: 350
Good information on this site, I have purchased from them happy customer
https://www.boatzincs.com/faqs.html
Attached Thumbnails
Click image for larger version

Name:	3EC8063D-FF92-46B8-A08C-A1308D84A2F9.jpg
Views:	40
Size:	131.3 KB
ID:	83686  
__________________

Capecodder is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off





All times are GMT -5. The time now is 04:19 AM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2006 - 2012