Re: [Amel Yacht Owners] Bilge Bonding strap connection to the keel - stainless steel or copper

James Alton


   Re Harvey.   I hope that you have some high ground.  Stay safe.

Using thicker copper sounds like a good solution to me.  Using stainless as wire to carry low voltage does not seem like a good idea to me either.   It might be worth looking at using coatings or a plating such as Tin to extend the life of the copper as is done with wire.  Pure copper is actually quite corrosion resistant.  Copper rivets for instance are one of the longest lived fastening methods for wooden boats.


Sent from Samsung tablet.

-------- Original message --------
From: "'Bill & Judy Rouse' yahoogroups@... [amelyachtowners]" <amelyachtowners@...>
Date: 8/29/17 14:51 (GMT+01:00)
To: amelyachtowners@...
Subject: [Amel Yacht Owners] Bilge Bonding strap connection to the keel - stainless steel or copper



Thank you for posting this information. I know several people who have used Stainless Steel rather than Copper. BUT, you know that I (Mr. "keep it original") will have more to say about this here goes:

I have considered the same thing. But, there is a RISK in substituting Stainless Steel for Copper, but I cannot quantify the RISK, I can only state it.

The RISK issue is that copper is many times more conductive than stainless steel. Additionally, we are talking about low voltage and low amperage conducted in the bonding system. I believe that Amel could have done better and used Copper bar with a thickness of about 3-5mm, and that is what I recommend. My experience is that this will have a life of about 10-12 years, if in constant use.

I also think that until there is an expert quantitative analysis of the substitution of copper with stainless steel, the very low reward of longer life isn't worth the RISK.

I saw a posting from Philippe (SM BELAVITA SM 238) that Alban at Amel Martinique made a stainless steel bonding strap for his boat. He also stated that he personally used stainless steel for "earth" connections in chemical reactor design. I should remind everyone that bonding and earth are two entirely different things. The difference in potential voltage and current between these two uses is huge. Bonding is very low voltage and amperage. I am sure that corrosion was a much bigger issue in chemical reactors and stainless steel was the best solution regarding corrosion.

I am not trying to be critical of this stainless steel solution for the keell bonding strap. I am only warning that it might not be the best thing to use as a conductor for bonding. 

We sailors and people who work in areas that are subject to the corrosive effects of saltwater, freshwater, electrolysis, and increased metal oxidation; are inclined to solve these issues by using stainless steel, BUT, as we all know, it is not always the best product when considering all of the issues.

Writing you from near the eye of HARVEY on Galveston Island, Texas.


CW Bill Rouse
Admiral, Texas Navy
Commander Emeritus

Amel School
720 Winnie St
Galveston Island, TX 77550

+1(832) 380-4970


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