Zinc opions

[Steve Laume]

I went down to the boat the other day to bring her into her winter slip. I could hear that tell tail tingle of a lose zinc. When in the slip for the winter I always rig a big zinc grouper over the side and attach the clip to the back stay fitting. That way I am assured I am protected in the marina. The problem is the rest of the year. My shaft situation is such that I can only fit a perry nut on the end aft of the prop. These things just love to fall off. When I hauled this July I fitted new zinc and locktighted the bolt that holds it in place. So it has stayed on for a few months but I have about had it with these silly things. Any ideas for mounting a big mother zinc on the hull somewhere and then bonding it to the metal parts of the boat? Could I find a spot somewhere towards the aft end of the hull, out of the slip stream and bolt a big old zinc on there. I could then attach wires to the bonding system inside of the boat. What about attaching to the bronze bonding plate itself? I want a big zinc that is not spinning with the prop and falling off well before it is used up. For that matter I am not sure if it gets used up or not but I typically stay in the water for two years before hauling and want a zinc that could stand the test of time. I can always dive to replenish it but the perry nuts just don't seem to be the right approach. Anybody go this route or have details of how a hull attached zinc should be installed? I am ready to do this once and be done with it for a couple of years, Steve.

[Russell]

Why dont you just use the grouper all the time? Why only when in a slip? Anytime I am not moving I hang one over the side. It helps a lot, but I still have to change the prop zinc every 6 months or so (but at least the water is warm and clear here!).

[tmsc]

Steve, Russel, et al,


For frp boats a better option than zinc anodes are the aluminum alloy anodes like those by Performance Metals. These normally last significantly longer and provide plenty of protection. Moreover, they function in fresh, salt and brackish waters unlike zinc which will go to "sleep". They can be a little more difficult to find but IMHO are worth the effort. Boaters World used to carry the reduced clearance collar style like I use on my 33 but have discontinued them. You may find some on the shelf though. However, Go2 Marine does carry them.

http://www.performancemetals.com/default.asp

http://www.go2marine.com/category.do?no=17814

[Steve Laume]

I am not so much worried about how long the perry nut lasts as with how long it actually stays on the end of my prop shaft. It is definitely not warm enough to dive, comfortably, here for the entire time I have my boat in the water. The grouper is great but would be a pain to flop in and out of the boat all summer. Maybe a minnie grouper with a shorter cable tied off to the new Monitor would work for me. I am just trying to get away from the perry nut that never seems to stay where I put it and is pretty expensive to replace. The worst part is that I am never sure it is really there at all, Steve.

[Bob Maguire]

Steve,

I have used the zinc grouper anode for years. I hang the zinc over the side and make a wrap around a winch and run the line into the cockpit locker and through the locker to the engine block where I connect the alligator clip to the engine mount bolt. Has worked like a charm for years. Before I get underway I pull the zinc up, coil the line and then place it in a ziplock bag inside the locker.

[M. R. Bober]

In Baltimore they use the kitchen zinc, hon.

Mitchell Bober
Sunny Lancaster (where we remember our personal histories), VA

[Chris Reinke]

Steve - have you considered a rudder mounted zinc? I had one on a boat a few years back and it never came off unless I worked at it...and worked at it...and worked at it. It simply bolt through the rudder. In my older boat I had a metal skeleton inside the rudder which it mated up to. I am not sure how the CD rudder is constructed but it may offer an option.