This blog is devoted to my John Welsford designed 15' Navigator yawl Ellie. I built her in my garage over a period of 18 months and launched her in 2011. She sports a sliding gunter main, roller furled jib and sprit-boomed mizzen. Her construction is glued-lapstrake over permanent bulkheads and stringers. This blog is a record of her construction and her voyages here in the Puget Sound area and (hopefully) a useful resource for fellow Navigator builders.

Saturday, July 6, 2019

Centerboard Maintenance

Ellie was launched in 2011. She has seen a considerable amount of use in the 8 years since her launch, both on the water and on the road. She’s been repainted several times, both inside and out, but her centerboard has never been removed and inspected since her launching. Time for some overdue maintenance!

To be honest, I was a little bit afraid of what I might find. Her centerboard has always worked perfectly, but that doesn’t necessarily mean all is well below the surface.

So I summoned up some courage, removed her pivot bolt, removed the centerboard and brought it to the workbench.


The board looked pretty darn good. A quick inspection revealed no major issues. No soft spots, wood rot, or significant damage anywhere, thank goodness. Just a bit of normal wear and tear.

The first thing I noticed was some missing black paint. My centerboard was constructed of Alaskan Yellow Cedar, sheathed in epoxy and fiberglass, sanded, and painted with Rustoleum alkyd enamel spray paint. One of the lessons I learned while building Ellie is that paint will only stick to epoxy if the epoxy is well sanded until it looks “frosty”. Epoxy cures to a smooth, shiny and slightly waxy finish that paint simply will not adhere to. Everywhere you see missing paint on my centerboard, you will also find glossy epoxy. These areas will get a more thorough sanding before they get repainted.



Paint was also missing in areas that get some wear and tear. The entire leading edge of the board is missing paint. I sail over the Snohomish river bar very often. The bar is sandy, shallow and thick with seaweed. You can see where the sand and seaweed has worn off the paint.
There is also a bit of missing paint on the sides of the board, where the board rubs up against the inside of the centerboard case.

And one ding on the bottom of the board.  I'm not quite sure where this came from.  I may have hit a rock at some point.  This will need to be filled with epoxy.
The area with the most wear is the area around the pivot bolt, as one would expect. Here the paint has been worn away, and much of the epoxy coating. Even the fiberglass has started to wear a little bit. It’s a good thing I decided to do this maintenance now, before it wore through the fiberglass and into the wood itself.



This wear can be repaired quite easily. I’ll give it a light sanding and a fresh coat of epoxy or two on the worn areas. Then the entire board will get sanded, followed by several coats of paint and the board will be as good as new.

The hole where the board pivots is in perfect condition. When I originally built the board, I made a "bushing" here by drilling an oversized hole in the board. I filled the hole with a mixture of epoxy, chopped fiberglass, and silica. After that cured I drilled a smaller hole through it for the centerboard pivot bolt. I did the same procedure in the centerboard case. This creates a hard, waterproof bushing that will never wear out.  The procedure is described in detail here.

It’s easy to forget to maintain your centerboard. Don’t let a small job become a big problem!

6 comments:

  1. Nice work Joel. Have you considered just using graphite powder in the second or final epoxy coat. That worked well on Noddy’s board. I forget the percentage of graphite to add to the mixed epoxy. Too little and it doesn’t go on black enough s test on a piece of scrap wood. It takes quite a bit.

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    1. Hi Simeon. I haven't looked into graphite powder and I don't know much about it. It sounds like a great idea. This would be a great time for me to do some research. Thanks for the suggestion.

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  2. Hey Joel - hope you are well; enjoyed the Facebook postings about the Sailfish 100?? Did I get that right?
    Now I'm feeling guilty - poor Arwen - a couple of years older than Ellie and has only been repainted once! shameful - I am a poor skipper and she deserves better. This winter I'd better drop her centreboard and check!! Did you drop the centreboard or lift it out of the top of the slot, just out of interest?

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    1. Hi Steve. Actually it's "Salish", not "Sailfish". The Salish people are a group of Native Americans here in the Pacific Northwest. The Salish Sea, consisting of the Puget Sound, Straight of Juan de Fuca, and the Straight of Georgia was named after them in their honor.
      I lift the centerboard from the top of the slot. I tried removing from the bottom but that didn't work because part of my trailer gets in the way.
      Excellent work on your blog BTW. I've been enjoying your videos very much.

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  3. Well done, if that job has to be done every 8 years or so, thats not that big a deal.
    Good to see its standing up so well.

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  4. Must be the summer for centerboard maintenance on Navigators!! I’m in the middle of doing the same. I’ve had the centerboard out a couple of times and I found that by taking a couple of tie down straps and dropping a loop under the center board from the top, I can hang the board in place while I pull the bolt, then just pull it straight up and out.

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