Dealing with some corrosion…

We are trying to attend to some aspects of Riki Tiki Tavi that need attention from time to time.  One of the issues we face is galvanic corrosion.

When two dissimilar metals are in contact with each other, there is a tendency for electrons to move from one to the other.  In this case salt water is the electrolyte,  the aluminum Lewmar block housing is the anode, and the stainless steel support is the cathode.  The remedy is to separate the metals thereby not allowing them to touch each other, stopping the flow of electrons and hence the corrosion.  Originally this was done with a piece of rubber mat, but over time this began to fail and have small holes, and then let the electrons flow… We found a replacement in our recycling bin.

It looked like this:

the disassembly

So first I took it apart.  Here you can see all the nuts and bolts and also the rubber mat that needs to be replaced.  The white powder is corroded aluminum.

I then cleaned the stainless steel support as well as the hardware and aluminum piece.

bolts before cleaning

 

looks lke a banana slug toothbrush, to clean bolts

 

Then came selecting a suitable new separator….  we had an old yogurt container on hand, as well as an empty milk jug.  Good enough.

yogurt

 

Next we had to trace where the bolt holes would need to be as well as how large the entire piece needed to be to ensure no touching of stainless with aluminum.

trace

To punch the holes, I used a single hole punch like you’d use for paper.

hole punch

After everything was clean and dry, I liberally applied some Lanocote which helps protect and neutralize corrosion products, should there be some corrosion developing in the future (always seems to be happening).

lanocote

 

more lanocote

ensuring proper fit of bolts through plastic

And voila!

almost done

A little trimming and then done 🙂

IMG_20150317_163431 done

7 thoughts on “Dealing with some corrosion…”

  1. We have been using a different method for the past 20 years and it has worked better than anything else we have tried. It’s quick, fool proof and easy to punch the bolt holes thru.

    The answer is plumbers tape a 2″ PVC thick tape with one adhesive side. It’s use to wrap copper pipes before pouring concrete around them.

    http://www.lowes.com/pd_134116-13188-TA-33-PW21_4294715748__?productId=3433996&Ns=p_product_qty_sales_dollar|1&pl=1&currentURL=%3FNs%3Dp_product_qty_sales_dollar%7C1&facetInfo=

    First we remove the fitting, clean the side that will touch the aluminum or SS with acetone. Then cut a piece of tape and fix on the underside of the fitting. Quickly trim with a razor blade. Using the bolts that will hold the item onto the base just punch the bolt hole thru the fixed plumbers tape. Volia 20 seconds from start to finish.

    Hope this helps

    Chuck
    Jacaranda
    http://www.jacarandajourney.com

    1. Thanks for sharing Chuck. I’m hoping to be able to leave this alone for a while but when it needs attention again, and I if I’m able to have some of the tape you mentioned, I’ll give it a try 🙂
      Cheers,
      Sara of RTT

    1. Thanks guys :). We’re thinking of you as well! So exciting about your upcoming trip to FP!!!! Looking forward to hearing all about it. Much love, RTT crew

  2. Hey Sara

    I’m sitting here with your mom and she was showing me your website and all your amazing adventures. They have been down for 2 days and are heading home tomorrow back to Florida. We are ecstatic that you guys have been having a great time and are experiencing so many awesome things. Your mums telling me I should tell you what I have been up to so I’ve been working at the Bay of Quinte Yacht Club as a race coach for the past 2 years and I am heading off to college this September for electrical technician and automotive technologist. Abby is going into grade 7 and is growing up way to fast more my liking. My mom and dad are enjoying their vacation and are crazy busy.

    ps. your mom wanted to toot my horn so here it goes I was nominated Ontario junior citizen of the year last year and attended the pan am and parapan am youth summit as a youth ambassador.

    Hope you guys are having a great time and maybe we can all be in touch.

    Sincerely,
    Coulter and the rest of the Rashotte family.

    1. So great to hear from you this way :). Thanks for sharing! You sound like you’re well on your way!! I hope your program is going well and that you’re enjoying yourself in the process. We are currently gearing up to leave San Diego and head for ensenada. It’ll be our first time checking into Mexico… Hoping to get to la paz by early December…. It’s kind of cold here these days… Reminds me of Canada :). Glad to be in touch!! Your cousin, Sara

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