Missing Zinc

[BobFuller]

My Beneteau 281 has a badly corroded three blade prop that I am going to need to replace this winter. When I bought the boat last October (2003), the bullet type zinc that fits on the end of the prop was missing and the prop looked to need reconditioning. I had the boatyard where I purchased the boat install a new zinc but when my marina pulled the boat for the winter a month later, the zinc was gone.  Last spring, the marina service manager reported that the prop was beyond reconditioning and supposedly ordered a new prop which didn't arrive by the time to put the boat back in the water. They put on another zinc and promised to pull the boat and install the new prop when it arrived. It never did and when I pulled the boat last week, the zinc was again gone and the prop is now in very bad shape. I don't know if the boatyards used a special zinc or a generic bullet type that may have been too big or heavy as I never have seen a zinc on this boat.  Has anyone else had this problem keeping zincs on the end of the prop? I have ordered a new prop and new zincs from Beneteau so the replacement zinc is sure to be the correct one. Does anyone know any tips or tricks to removing and installing the prop and also for installing a zinc so that it remains on the prop?

 

[Rob Leimgardt]

Prop Zinc Is 1 part of complicated equation

Bob,Although you are correct in replacing this Zinc, you may have more suitable solutions to an obvious existing problem. I am going to assume that yu have done your homework on galvanic corrosion, and its oh so costly effects on vessels. That said, you may need to 1.Improve on, or install a proper bonding system for your vessel, 2. Become aware of the vessels and the environment surrounding your 281, many times corrosion can be transferred to your vessel through other poorly maintained vessels docked close to you, 3. Same goes for the shore power system you a using, this can also be a source for a ongoing problem, 4. Install a plate zinc on the bottom of the hull.Good luck, take this very serious as you will eventually find it can be a very costly point of vessel preventitive maintenance.P.S. Don't forget about your engine and its pencil Zincs, if you are fitteed with aux. power

 

[Charlie Gruetzner - BeneteauOwners.net]

one step further

Bob, Rob's advice wouldn't have been any different then mine. You obviously have something going on there. I will say that there are a lot of variables including water pollution levels etc. that add to the situation. I know on my B361 I check the zinc on the propeller monthly and usually end up changing it mid-season. It is best to change them when they are about half gone as a regular maintenance program. As a bit of a follow up to what Rob said. Look at the boats that are near you and while they are on the hard see what their zincs, prop etc. look like. If there are a number of them then I would venture to say the problem is in the yard not the boats. It is interesting that your propeller never came in - that says something to me about the boat yard. If the boats around you are okay in the Spring you might want to see if you can beg, borrow or steal a portable corrosion meter (if you are in saltwater make sure it is an analog not digital meter) with a silver/silver chloride and check out your boat out yourself or get an ABYC certified corrosion tech to do it. In the long run the expense of the tech will be will worth it. Good luckCharlie Gruetzner

 

[Rob Leimgardt]

Cart Before The Horse

Bob,Got to thinking...are the bolts that attach this zinc there? Or are they missing as well? I ask this for obvious reasons, this may be as simple as a installation problem at the yard. ie. wrong thread diameter or standard vs. metric or vice versa.