fstbttms: Could you let us know what sorts of on board problems may lead to rapid zinc depletion or where to read more about this?
Thanks!
Zinc - Galvanic isolator
- Thread starter Richard19068
- Start date
Thanks!
One thing that I have not noticed mentioned here is the zinc itself. You may have an electrical problem on board and yet if you can't find one then there are other considerations to contemplate.
One may be to recognize that there are zincs on the market that are coming out of China that use far less quality control with regard to the materials purity used in the manufacture of the anodes. I would look for anodes that meet mil specs. that are far more stringent than those on the other side of the pond.
With the high salinity of the water where you are, perhaps consider obtaining anodes that meet mil specs or that are made of Aluminum. Aluminum has a higher relative energy capacity per pound of material than does Zinc (Al has 1,108 amp hours per pound vs. Zn at 368 amp hours per pound).
Get Nigel Calder's book and read it; worth every penny.
One may be to recognize that there are zincs on the market that are coming out of China that use far less quality control with regard to the materials purity used in the manufacture of the anodes. I would look for anodes that meet mil specs. that are far more stringent than those on the other side of the pond.
With the high salinity of the water where you are, perhaps consider obtaining anodes that meet mil specs or that are made of Aluminum. Aluminum has a higher relative energy capacity per pound of material than does Zinc (Al has 1,108 amp hours per pound vs. Zn at 368 amp hours per pound).
Get Nigel Calder's book and read it; worth every penny.
I'm no electrician, but I have seen DC current leaks into a wet bilge cause problems, not only with anodes but with the parts they are intended to protect. In the pic below, this prop was damaged by current from a bilge pump wire with broken insulation. Even though the issue was resolved by replacing the pump, the prop eventually fell off.
Here is an article that discusses the issue in plain language:
http://www.yachtsurvey.com/corrosion.htm
Thanks so much, sir. If I had read further, I would have seen that you and others identified issues with bilge pump wiring as the primary suspect.... I changed slips at the marina, and the zinc went to pieces in a few weeks in the new slip after staying whole for several months in the other. Could be a coincidence, so I will check the bilge pump circuit.
Excellent article on corrosion, BTW.
Thanks again....
Excellent article on corrosion, BTW.
Thanks again....