I am a new owner of an older, 1985, well maintained boat and want to keep it that way. A basic question not answered in the pristine old owners manual nor after an hour or two of searching the internet. Where are they and what are the part numbers. Thanks in advance.
Where are the Hunter 34 Sacrificial Anode Locations and what are their specs for ordering
- Thread starter Sarj
- Start date
Good question. Is it a fresh water boat?
A marine engine technician and I searched all over the engine and transmission for them, including the areas at the back and sides indicated by the Yanmar engine manuals and found none. He stated that it wasn't necessary in a fresh water boat. I still wonder about stray voltage at the marina though.
I ended up putting a magnesium anode on the prop shaft after seeing the severe pitting on the prop shaft anodes of the boats around me on the hard this winter at that marina.
A marine engine technician and I searched all over the engine and transmission for them, including the areas at the back and sides indicated by the Yanmar engine manuals and found none. He stated that it wasn't necessary in a fresh water boat. I still wonder about stray voltage at the marina though.
I ended up putting a magnesium anode on the prop shaft after seeing the severe pitting on the prop shaft anodes of the boats around me on the hard this winter at that marina.
If you can provide the model of engine, I'm sure we can help identify where, if any, the anode(s) are located.
Welcome to the club. Good you found a well cared for boat. To clarify some terminology for others, you most likely have the same engine I do...the Yanmar 3GMF22. It is a fresh water COOLED engine. This is to delineate the difference to a fresh water SAILED boat (like in a lake or river). The fresh water cooled engine circulates a mixture of antifreeze and regular water through the block and water heater much like a car. Then there is a heat exchanger (like a car's radiator) that transfers the heat to a raw water source. That raw water can either be from the ocean (salty) or a lake (fresh). The key is, the two processes (fresh water cooled engine and raw water heat extraction) never actually mix. So, with that being said, our fresh water cooled engines do not have any sacrificial anodes as part of the engines. There are raw water cooled engines (where sea water goes right through the engine cooling passages directly) that do have those anodes to protect them. Again, ours don't. However, the boat has anodes to protect the prop, and shaft and anything else that might be electrically bonded to the engine. For my salt water sailed engine, I use two 1" zinc anodes on the prop shaft. I noticed that my strut (which is not electrically connected to the engine by a wire inside therefore isolated from the shaft by the rubber cutless bearing) was turning pink, I drilled a 1/4" hole in it and installed a 3-13/16" flat rudder plate anode to it as well. I don't claim any expertise in fresh water sailed boats, other than knowing zinc anodes aren't the right choice. Whatever your requirement, the dimensions I have provided should be the same for you.
Thank you for the responses. I appreciate the advice and the photo of anode placement was very helpful. The boat was in the same slip in a freshwater lake until February 2015. Here she is hauled out last August for a survey. She had a full bottom job just a month prior. Another current concern is that there seems to be corrosion trailing in the bilge from the forward depth finder transducer. It still works but would like to keep it working. We have shallow bays and regular silting issues. I work at avoiding the 'Tow of Shame' from running aground.
I have two on the prop shaft and one each side of the iron keel. The engine uses a heat exchanger so no seawater circulates through the engine so no anodes in the engine.
Aftermarket. In fact, they were not there when I bought the boat. I had the boat hauled. They cleaned and epoxy coated the iron keel and added the anodes.
My understanding is that you really need them if you are in "hot" marina, i.e. a marina with stray current running around from the power supply. My marina, apparently, has this issue.
Well if you have some Aluminum in the fresh water, Magnesium anodes are better. The rate of loss of your sacrificial anode is slower in Fresh water than Salt water.
Galvanic corrosion works on your metals below water except if you are sailing on Lake Distilled Waters.
You can use Zinc, Aluminum, and Magnesium (listed Noble series order) anodes to protect Steel keels/shafts and Bronze props in fresh or salt. I just can't afford $$ the Magnesium rate loss in salt water.
Great Job!
Tip: Rate of loss of anodes is the ratio of anode surface area exposed, to the exposed metal surface area you are protecting. Weight of the Anode provides longevity between changes.
On Allan12210 picture, painted iron keel reduces the surface area of exposed metals to galvanic corrosion.
Jim...
PS: @Allan12210 separate the egg Zincs slightly to expose more Zinc surface to water.
Very Very very BAD news. Get the Marina fixed, exile the culprit boat or/and leave the marina NOW.
Jim...