Mast step corrosion?

[SeacretSailor]

Hey guys,

In inspecting my new (to me) boat, a '79 C&C 29ft, I found the beginnings of corrosion (bubbling paint) on the mast step below the cabin sole, where the grounding wire bolts onto the mast. The grounding wire runs from the keel bolts to the aluminum mast and bolts into the mast with a steel bolt. I know it galvanic in nature due to dissimiliar metals, the steel bolt and aluminum mast.

What's the best solution? An aluminum bolt?

Would appreciate your thoughts and advice?

Kevin B.

 

[Seattle Scott]

Kevin, Isn't the mast step already connected

directly to a keel bolt(s), such that the wire is redundant. But maybe you want redundancy in a lightning strike.

 

[higgs]

You are going to get advise from others who know a lot more about this than I. I wonder if the problem is not so much the dissimilar metals as it is with needing an external zinc. It seems to me that no matter what you do with the bolt in question, you are only shifting the dissimilar metal problem to a new location.

 

[sailingdog]

Best solution is to keep a dry bilge. Seriously...

If you can't keep the bilge dry, then you might want to look at cutting the bottom few inches off the mast and raising the mast step by the same amount, so that it isn't sitting in the bilge water constantly. This is a pretty typical fix for the problem of a corroded mast base/step. Ideally, the riser for the mast step should be solid fiberglass.

Hey guys,

In inspecting my new (to me) boat, a '79 C&C 29ft, I found the beginnings of corrosion (bubbling paint) on the mast step below the cabin sole, where the grounding wire bolts onto the mast. The grounding wire runs from the keel bolts to the aluminum mast and bolts into the mast with a steel bolt. I know it galvanic in nature due to dissimiliar metals, the steel bolt and aluminum mast.

What's the best solution? An aluminum bolt?

Would appreciate your thoughts and advice?

Kevin B.