Have to get some zinc shaft anodes for salt water, just wondering if anyone has any thoughts as to how long these will last in salt water. I want to get a few for stock. We use the streamlined ones that clamp onto the shaft in two halves. I believe what we have on there now is magnesium for fresh water but not positive on that.
Bud,
You most likely do have a magnesium anode for fresh water. It's really hard to predict how long a zinc will last in salt water. It all depends on how "live" your boat and the surrounding docks and boats are. My zincs generally last for our full sailing season (5-6 mos.). In some years I've had to replace them half way thru the season (I suspected a beat-up boat next to us, but you can't really accuse someone on a hunch). I've heard of some owners going thru a zinc every month. As zincs are roughly $10 each and don't take up much space, getting a half dozen or so should keep you supplied for a few years.
Tom Sokoloski
C36/375IA Past Commodore
Noank, CT
Lately, I find I am replacing the prop shaft zinc about every 4 months.
I don't have any shore power hooked up and there are no shore power facilities in operation within 200 feet of my boat. The last time I tested, I had no stray DC current problems, either.
Our canal water is up to 80F now, so I can dive the boat in comfort.
Duane Ising - Past Commodore (2011-2012)
s/v Diva Di
1999 Catalina 36 Hull #1777
Std rig; wing keel, M35B, Delta (45#)
Punta Gorda, FL
http://www.sailblogs.com/member/diva-di/
Bud, it literally "varies with the territory." My records show that over the past 14 years it has varied to one per year to two or three. Could well depend on who's next to you. We don't leave our boat plugged in when we're away from it.
PS - Nice note in Latitude 38. Goin' to "the cats & dogs", are ye?:)
Stu Jackson, C34IA Secretary, C34 #224, 1986, SR/FK, M25 engine, Rocna 10 (22#)
I agree with Tom and Stu, it will vary considerably as there are a lot of factors that affect the Zincs. Over the last two years of being in salt water I get about 6/9 months maximum, with some variance.
John Meyer
Hilbre 2135
John Meyer
Hilbre
C36 MKll, Hull 2135
Cabrillo Marina, San Pedro, CA
Thanks guys. Figured there would be some significant differences by area but just trying to get a sense of how many we should take. Up here in freshwater they seem to last forever.
Stu, the little buggar is getting a swelled head now! He'll probably decide he's too good to be the guard cat now.
Hey Bud just a FYI. We have a Max Prop with a zinc on the end of that and I also have a Zinc on the shaft, The one on the shaft was about half gone and the one on the prop was about the same. Just for fun I left the magnesium one on from the great lakes and when we got to Lucya I was putting on a new regular zinc as that one was gone. I figured it would be anyway. The one other zinc you better have in your locker is the one for the heat exchanger. I need to get more as I went thru 2 of them while on the 11 month trip. The size for mine is 1/2 dia by 1 1/4 with 3/8 threads which screws into the brass cap. For your shaft zincs here is a good web site as they have the better zincs, as not all are made the same. [URL="http://www.deepblueyachtsupply.com/boat-anodes/zinc-anodes"]http://www.deepblueyachtsupply.com/boat-anodes/zinc-anodes[/URL]
Randy
Randy Sherwood
Mutualfun 1990 # 1057
T/R W/K M35a
Home. Charlotte, Mi.
Boat. St Augustine,Fl.
Thanks for that info Randy, that was one of my head scratchers. I had no idea how long a magnesium anode would last in salt water so thought I might add a zinc as well but that just adds more rotating weight and drag so not my preferred solution. I stocked up on zincs for the heat exchanger, I had the HE rebuilt last fall so it has a new one and I have 3 spares, maybe I'll get a couple more.