|
Home | Forums | Gallery | Webcams | Blogs | YouTube Channel | Classifieds | Calendar | Register | FAQ | Donate | Members List | Today's Posts | Search |
|
Thread Tools | Display Modes |
03-25-2008, 12:07 PM | #1 |
Senior Member
Join Date: Jan 2005
Posts: 64
Thanks: 0
Thanked 2 Times in 2 Posts
|
Stern Drive Anode
I noticed the tiniest bit of oxidation on my boat's stern drive and my neighbor recommended I install an anode (and I've since learned that it ought to be a magnesium anode). I'm not certain what to do or where to install it/what style to get. The sterndrive is Volvo-Penta with an aluminum prop. Thoughts?
|
03-25-2008, 01:20 PM | #2 | |
Senior Member
Join Date: Apr 2004
Location: Eastern MA & Frye Island/Sebago Lake, Maine
Posts: 935
Thanks: 247
Thanked 323 Times in 148 Posts
|
Quote:
Blue Thunder
__________________
" Live for today because yesterday is gone and tomorrow may never come" |
|
03-25-2008, 01:39 PM | #3 |
Senior Member
Join Date: Jan 2005
Posts: 3,365
Thanks: 210
Thanked 764 Times in 448 Posts
|
You are correct on magnesium. Zinc tends to corrode on the outside and scale over instead of dissolving in a uniform manner. Magnesium is a much better choice. I think with the more rapid rate of electrolysis in salt water the zinc does not have time to scale and works just fine.
|
03-25-2008, 01:48 PM | #4 |
Senior Member
Join Date: Apr 2004
Posts: 1,325
Thanks: 5
Thanked 0 Times in 0 Posts
|
Review the reply that starts, "This is from boatzincs.com"
http://www.boatered.com/forum/topic.asp?TOPIC_ID=112161
__________________
[Assume funny, clever sig is here. Laugh and reflect... ] |
03-25-2008, 02:16 PM | #5 |
Senior Member
Join Date: Apr 2004
Location: Lakes Region
Posts: 547
Thanks: 9
Thanked 29 Times in 20 Posts
|
more than one anode
I have more experience with Mercruisers than VP, but I wanted to point out that you likely have several anodes (4-6) on the outdrive - the discussion here implies there is just one, which is likely not the case.
All of them need to be changed over to magnesium for fresh water use - they each protect different sections of the upper and lower drive assemblies... |
Sponsored Links |
|
03-26-2008, 07:02 AM | #6 | |
Senior Member
Join Date: Jul 2005
Location: Berlin, Ma / Gilford
Posts: 1,931
Thanks: 445
Thanked 604 Times in 340 Posts
|
Quote:
Perhaps this will help !! http://www.boatzincs.com/volvo_penta-magnesium.html And for those of you with MerCruiser -- and wonder where the annodes are ........... This gives a great pictorial http://www.boatzincs.com/bravo3-mag-kit.html for Bravo 3 http://www.boatzincs.com/alpha-one-gen2-mag-kit.html For Alpha 1
__________________
A bad day on the Big Lake (although I've never had one) - Still beats a day at the office!! |
|
03-26-2008, 10:20 AM | #7 |
Senior Member
Join Date: Apr 2004
Location: New Hope, PA & Barndoor Island
Posts: 464
Thanks: 93
Thanked 24 Times in 18 Posts
|
Do you need anodes on outboards, too? I have a Merc and a Yamaha. Never noticed if they have them.
|
03-26-2008, 11:50 AM | #8 | |
Senior Member
Join Date: Jul 2004
Posts: 2,974
Thanks: 246
Thanked 736 Times in 438 Posts
|
Quote:
I would fully expect anodes on your lower unit. Any time there's two or more types of metal in the water, the least noble of metals will dissolve through electrolosis. Anodes are less noble than the rest of the lower unit, so they dissolve first. If you tilt the the thing out of the water whenever it's at rest, the anodes will last years in our water. |
|
03-27-2008, 07:11 AM | #9 |
Senior Member
Join Date: Jul 2005
Location: Berlin, Ma / Gilford
Posts: 1,931
Thanks: 445
Thanked 604 Times in 340 Posts
|
Grady -- I would be SHOCKED if your outboards lower unit did not have them.
On the Merc, look at the under side of the Cavitation plate (above the prop).
__________________
A bad day on the Big Lake (although I've never had one) - Still beats a day at the office!! |
03-27-2008, 08:33 AM | #10 | |
Senior Member
Join Date: Mar 2007
Posts: 95
Thanks: 2
Thanked 8 Times in 5 Posts
|
Quote:
|
|
05-03-2008, 06:55 PM | #11 |
Senior Member
Join Date: Feb 2008
Posts: 50
Thanks: 3
Thanked 5 Times in 2 Posts
|
can u tell by looking?
what type they are? how do i tell if my alpha 1 has salt or fresh water anodes?
|
05-03-2008, 08:23 PM | #12 |
Member
Join Date: Jan 2005
Posts: 20
Thanks: 0
Thanked 0 Times in 0 Posts
|
bravo 3 drives use an aluminum anode. The idea being, the bare anode will carode before the painted i/o.
|
05-04-2008, 09:38 AM | #13 |
Senior Member
Join Date: Jul 2004
Posts: 2,974
Thanks: 246
Thanked 736 Times in 438 Posts
|
|
Bookmarks |
|
|