Scarfing gunwhales

Making up the gunwhales has been a lot harder than it had any right to be.  The spec is for 3/8″ by 1 1/2″ by ~ 20 feet, in hardwood, four pieces for inner/outer/port/starboard.  Of course, you can’t get this length anywhere in wood like mahogany or sapele.  So, one must scarf smaller pieces together.  In this case, the starting material is planks 1  3/4″  x 10″ x 10 feet of African mahogany.  These weigh about 50 lbs.  I made many trips to lumber yards looking for smaller stock, belive me!  The first step was ripping 3/8″ planks from the boards.  I was going to use my imaginary bandsaw,  or take them to be milled at a lumber yard, but in the end I used the POS $99 table saw, which I think weighs less than the boards I was cutting.  The bandsaw would have been better, since the kerf is smaller (less wasted wood), and my imaginary thickness planer would have done a great job making the long planks uniform and pleasing to the eye.  The big boards had warped a bit in the few months since I had bought them (even though they were stored flat on the concrete floor), and when the planks were cut, they sprung more, which is a pretty common thing as the internal stress in the wood is relieved.

To cut scarfs, one needs to taper with an 8:1 ratio, and there are a bunch of ways to do it.  Over the last couple of months, I was screwing around with using the table saw or a hand plane.  A lot of people use routers or hand-held belt sanders, but all methods require a jig of sorts.  I settled eventually on using the circular sander and the worlds cheesiest  jig, pictured below.  It worked as well as the handplane method, which had a problem with tearouts in the mahogany.  All you do is jam ’em in and play it until the cut face is about 3″ long (i.e. 8 x 3/8″).  I then clean up the face and angle with the beautiful block plane.

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Below, the old strongback is used as a table and clamping surface to hold the two pieces as they are glued up with fast curing expoxy mixed with sanding dust. 

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Above and below, the final product.  Not too bad, except the boards still aren’t straight — they will need to be forced to conform to the shear line anyway.

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Next, setting up the $98 POS to reduce the width to the final 1 1/2″, and then round over two of the edges with the router.  The board faces also need a lot of sanding to remove sawmarks and burns from when  the were ripped.  Why did I spend more than twice as much on a circular saw than a table saw?  I should have listened to Chief!  But now I know how to get out those planks, I’m looking forward to building up the i’akos and especially the ama, which will be fun.

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Meanwhile, while I was working in the boatshed, our own Christmas wahine decorated the tree all by herself! Hi Joe!

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5 Responses to “Scarfing gunwhales”


  1. 1 Buck

    Thanks for the progress report. I’ll remember your hard-won lessons on tools as I work on my own projects!

  2. 2 Ted Hardie

    I haven’t taken a peek at your Ulua project in a long time but must say it’s really looking good, beautiful is probably a better word. Your patience is paying off big time.

    Not to worry, any slight warp in the rails will come out when you glue the three elements together on the hull. You’ve probably already figured that one out….

    Will check back again to see the progress and enjoy your blog.

    All the best

  3. 3 Ted Hardie

    Just checking in to see your Ulua progress. Looks like your between things…. I had a bit of an involuntary break in the middle of my Ulua…must say it was very patient while I sorted things out. Hope all is well.

    All the best

  4. 4 bastcilk doptb

    Merely wanna remark on few general things, The website design is perfect, the subject matter is rattling good. “Art for art’s sake makes no more sense than gin for gin’s sake.” by W. Somerset Maugham.

  1. 1 Some scattershot Ulua progress | Never Sea Land

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