Fresh water- zinc or magnesium

PhilR

Well-known member
Joined
Feb 3, 2011
Messages
416
Fluid Motion Model
C-28
Vessel Name
TUGALONG
Most of the discussions about zinc anodes refer to salt water use. My boat will spend 6 months of the year in a fresh water lake. I normally don't plug in to shore power when I'm not there..only when I'm on the boat and using the AC unit. I rely on the solar panel to keep the batteries charged. Are magnesium anodes used in fresh water rather than zinc and what is the average replacement frequency? My previous boating experience has been with trailerable boats that lived on land....this issue is new to me.

Thanks, Phil
 
I use my R-29 in a fresh water lake in the summer and out on the ocean in the winter. I also do not plug into shore power. I have solar also.
Your zincs will last longer in fresh water. It is still a good idea to keep a eye on them. You can still run into problems if you are in a marina and you are next to a hot boat or on a hot dock. So it is good to keep a real close eye on them for the first few months.

My zincs last all summer long in the lake. I change them when they get to 50%. That is when I haul my boat out to the ocean for the winter. With that being said it is important to note that I do not store my boat in salt water. When we are done cursing i take her out on the trailer and flush out with fresh water, inspect all zincs,shaft and prop. Then put my full custom sunbrella cover on her that has clear panels that are over the solar panels so batteries stay full, and put her in dry storage.
I do not have bottom paint at this point. There is no reason to have it the way we use it. once a month I will bring her home from the lake and power wash the bottom and do whatever maintenance i feel I need to do. There is not any real bottom growth at this point but I just like to stay after it before it has a chance to build up.
When we are on the ocean I am never in for more then a month and it is not a issue. We are moving alot so it never has a chance to build up. Nothing worse for a boat then to sit. We have over 300hrs on our boat that we have had for just over a year.
I also put at least three coats of 3M wax on her a year. Yes that is done even know I cover her when she is out of the water. It is very easy to do while it is out of the water. My boat will still look new after many years down the road.
The trick is to wax her before you ever think she needs it.
Well that is more then you asked for ,but hope it helps.

Stuart R-29 Spirit of Gratitude
 
Generally one uses magnesium or aluminum anodes instead of zinc with aluminum outdrives or outboards. However, I would check on the recommendations for the thrusters to be sure that an aluminum or magnesium annode is not suggested. The pencil zinc annodes in the cooling system will probably be OK because the metals are fairly noble--and you are rarely pluged to dock power (which may cause greater risks of miswiring in a marina).
 
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