Grounding plate porosity

Jan 15, 2006
6
-Irwin Citation -31 Freedom (Oxford, MD)
EACC4861-9539-4E7A-9CB9-BF7B87F043BA.jpeg


My 8”x3” grounding plate doesn’t look right. I know some are porous bronze but this looks like stainless and is non-magnetic. It is only connected to mast and stays not bonded to thru hulls for lightning protection. It looks like severe wormy stray current corrosion even in the machine screw heads. I pull my boat every 2 years and the two prop shaft zincs are about 1/2 gone. I never plug my boat into shore power nor rarely do my boat neighbors. Thoughts?
 

dLj

.
Mar 23, 2017
3,373
Belliure 41 Sailing back to the Chesapeake
View attachment 190378

My 8”x3” grounding plate doesn’t look right. I know some are porous bronze but this looks like stainless and is non-magnetic. It is only connected to mast and stays not bonded to thru hulls for lightning protection. It looks like severe wormy stray current corrosion even in the machine screw heads. I pull my boat every 2 years and the two prop shaft zincs are about 1/2 gone. I never plug my boat into shore power nor rarely do my boat neighbors. Thoughts?
Bronze is also non-magnetic. Just a FYI...

Can you give me a bit more information on where this is located and exactly how it's connected to your boat? Looks to me more like a SSB ground plate. Do you have a SSB on board?

Your profile says Oxford MD, is that where the boat is located? Like Campbell's boat yard or thereabouts?

dj

p.s. obviously if you prefer to provide location information outside a public forum, feel free to PM me.
 
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Likes: jssailem
Jan 15, 2006
6
-Irwin Citation -31 Freedom (Oxford, MD)
Bronze is also non-magnetic. Just a FYI...

Can you give me a bit more information on where this is located and exactly how it's connected to your boat? Looks to me more like a SSB ground plate. Do you have a SSB on board?

Your profile says Oxford MD, is that where the boat is located? Like Campbell's boat yard or thereabouts?

dj

p.s. obviously if you prefer to provide location information outside a public forum, feel free to PM me.
Yes it’s at a private slip in Oxford. No SSB wire from keel stepped mast shrouds and stays connected to it. I wonder if I have a bare pi’s wire on my masthead light. Need to check lead from mast and amp draw. I bought a silver chloride ref cell to evaluate zincs but I don’t think there are dissimilar metals attached to the plate so should not be galvanic but if so could be crevice corrosion from the hullside outward. I’m perplexed
 

dLj

.
Mar 23, 2017
3,373
Belliure 41 Sailing back to the Chesapeake
Yes it’s at a private slip in Oxford. No SSB wire from keel stepped mast shrouds and stays connected to it. I wonder if I have a bare pi’s wire on my masthead light. Need to check lead from mast and amp draw. I bought a silver chloride ref cell to evaluate zincs but I don’t think there are dissimilar metals attached to the plate so should not be galvanic but if so could be crevice corrosion from the hullside outward. I’m perplexed
Check your PM's.

dj