Prop Zinc
- Thread starter Ron M
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It's probably not the method you use to secure it but the erosion of the metal around the fasteners. Some wise old salt once suggested to me to paint a small area around the perimeter of the fasteners to preserve only that small portion of the zinc. In my case, it worked.
I've had this problem in the past and used a bit of sealant/caulking on the screw to stop the zinc from falling off. The area around the screw is the smallest/thinnest part, so it goes first and the majority of the zinc falls into the water. I make sure the zinc still has contact with the shaft so it can do it's job. Since doing this, my zinc has stayed on every year and it has corroded from the outside but the inner most part, next to the screw survived enough to keep it attached.
I have an Autoprop on mine and it uses nylon bolts to screw the zinc to the end of the prop. Never understood why nylon and not a conductive metal. Mine also wears off and falls off. I'll try the paint but would like to use ss screws if there's no reason not to.
Lee
Lee
Loctite...
Loctite won't isolate the thinnest area of the zinc, which is where the screw is.
autoprop
I would stick with the nylon screws; different metal screws could cause corrosion and you wouldn't be able to remove them to replace the zinc. You can use waterproof marker to coat the inside and outside of the screw holes to retard wear at these points, which I do and it keeps the zinc lasting longer.
By the way, if the screws are gone, then the problem is not corrrosion, because the plastic screws don't corrode.
I would stick with the nylon screws; different metal screws could cause corrosion and you wouldn't be able to remove them to replace the zinc. You can use waterproof marker to coat the inside and outside of the screw holes to retard wear at these points, which I do and it keeps the zinc lasting longer.
By the way, if the screws are gone, then the problem is not corrrosion, because the plastic screws don't corrode.
Beneteau prop zincs are too small to last long. In my neck of the woods, they typically last only a couple of months. Consider adding a limited clearance collar to the shaft. These are specifically designed for use on the very small amount of exposed shaft found on various French boats. You need the 25mm size:
http://www.boatzincs.com/beneteau-donut-collar-specs.html
http://www.boatzincs.com/beneteau-donut-collar-specs.html
Does it need to be on the part of the shaft coming outside of the boat (behind the prop)? Will it work if you just installed it inside?Beneteau prop zincs are too small to last long. In my neck of the woods, they typically last only a couple of months. Consider adding a limited clearance collar to the shaft. These are specifically designed for use on the very small amount of exposed shaft found on various French boats. You need the 25mm size:
http://www.boatzincs.com/beneteau-donut-collar-specs.html
Yes, it must be on the shaft, forward of the prop, in the water. It will do nothing if installed dry and inboard.
I have the same prblem with my prop zinc. I get about 2.5 months out of it. I also plan to try painting (or nail polish) around the base and bolt holes.
Has anyone heard about prop zincs with a supporting aluminum ring molded in to prevent this? I though I saw that on a web site but can't find it now...
Has anyone heard about prop zincs with a supporting aluminum ring molded in to prevent this? I though I saw that on a web site but can't find it now...
I think this (plus nail polish) is the answer. I actually do have a max prop.
Now I need to connect this product with my diver!
Now I need to connect this product with my diver!
If you isolate your zinc from the bronze prop with some coating your are defeating the purpose of the zinc.
Once a max prop zinc dissolves partially it tends to spin off center, catch a prop blade and that snaps the whole zinc off.
Do you have an AC electrical system isolator?
Ron,
I try to keep both installed on my 331.
The Collar will fit on the 331 centered in the small exposed section of the shaft in front of the prop.
The screw that comes with the B331 prop zincs I order from Boatzincs.com already have some locktite applied.
Thanks for all the great info. Yes... I installed a galvanic isolator at the beginning of last season (May 2012). The extra zinc sounds interesting, does this need to be "wired" to the engine or prop shaft? Seems like a zinc alone will not accomplish much.
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