Re: [Amel Yacht Owners] Re: Engine exhaust hull fitting and copper water lines

John Clark

Hi Eric,
   thanks again.  I seem to remember the Rust Block primer from my submarine days.  Yes is was quite effective, but I think it was for ferrous metals more so than copper.    What I learned about copper corrosion augmented by salt water is that there are salt ions in sea water that act as a catalyst for the oxidation of the copper.  Even if the initial source of water is corrected the ions can attract moisture out of the air, just like a desiccant pack.  The prescribed remedy is to clean the pipe and flush the ions off the surface, dry, and then coat with a protectant, perhaps Rust Block.   The challenge I have is that the pipe surface is no longer smooth and has a lot of little cracks and crevasses that would require aggressive cleaning to clear out the catalyst. For my case cleaning might actually do more damage.  Second the location, behind the generator is not the easiest to access nor a place that I want to put a lot of flushing water. 
 My "in a perfect world" choice would be to replace the affected stretch of line, but again given its location I don't want to try to brazing in that space.   Maybe when the water heater needs replacing or it's time for a new generator and I have better access I will replace the lines. 

I opted to try the Corrosion X because I have good visual access to the site, and the lines are not presently leaking, replacement of the exhaust hose and repair of the adapter insert will eliminate the source of the water so the lines should remain dry going forward.   Corrosion X's primary anti-corrosion mechanism is to block access to the surface of the metal. This should block the O2 and moisture from contacting the metal.  Corrosion X also claims to be able to displace the catalyst ions.  Don't know about that but we shall see how it does.   

Yes, I have currently hoses that I can use to bypass the affected area should it start leaking.    I also placed on of my water detectors in the pocket under the tubing to detect leakage.  I will headed to Martinique in a few months and see if Jean Collin has any ideas or correct sized tubing.

                               Thanks Guys,
 John Clark
SV Annie  SM 37
Morehead City, NC

On Thu, Oct 5, 2017 at 8:42 PM, 'sailormon' kimberlite@... [amelyachtowners] <amelyachtowners@...> wrote:


My friend Eric Forsyth swears by Rust Bullet. I can attest to its efficacy.

Eric incidentally has logged 375,000 miles on his home built 42 foot west sail. 2 circumnavigations, northwest passage, many times to the Antarctic. He is headed to Portugal from Madera at age 85 as we speak.

If you have a time look at his website and his book that was just published.

He is also a CCA Blue water medal recipient.

Fair Winds


Kimberlite Amel Super Maramu #376



From: []
Sent: Thursday, October 05, 2017 11:18 AM
Subject: [Amel Yacht Owners] Re: Engine exhaust hull fitting and copper water lines



Thanks Eric and Bill.  


I spent the morning with Dr. Google learning about copper corrosion. Seems that there is a lot of chemistry involved and that the corrosion can be tough to knock out without aggressive cleaning.


 I like the idea of painting the lines, but they first need to be cleaned better than I am able to do in that particular corner of the ER.  I did clean off the loose blue flaky stuff and vacuum the area, but cannot get in there to wet clean and flush the lines.  My concern with a non neutralizing paint is that the corrosion can continue, and I won't see it.   

Corrosion X claims on their website that it can displace the salts that are causing the corrosion on the copper lines then protect them with a waxy film.  What do you think about Corrosion X instead of paint?   To me an "advantage" is that I can visually monitor the situation and if corrosion persists then replace the lines before they leak. 

 I think I will get a micrometer down there today and figure out the line size and see if I can get some "spare" tubing to have on hand just in case.   

                    Regards,  John


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