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Lapwing #5 build


John Turpin

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Lapwing #5 is now under way here in Edmond, OK--the B & B Yacht Capitol of the World.  Why do I claim that title for this little town in Oklahoma?  Well, five miles to the east of me sits a Princess 22. Five miles to the south sits a Core Sound 17. Five more miles south is a Belhaven under construction. Three years ago, a Two Paw was built here at my house. Outside of Vandemere NC, can another city compete with that?  Hey, we just love B and B boats here.

Anyway, I started cutting wood this morning and will be documenting #5's build here:  http://www.tetra-sail.com/lapwing.htm

I'll try to post photos from time to time.

John

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Cool deal, you've got the first cut done - B&B will be well represented at BOOTS.  Get your friend with the CS17 to join up and with Tim that will make two of those, I hear there will someday be another there, and Pilgrim, of course, your Lapwing - quite the sharpie fleet!

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I have been away for the weekend - so only tried to answer your email today.  I have tried three times, but get bounced back as spam from your provider for some reason.  

Hi Richard.  I don't know what's going on with your emails.  That hasn't happened in the past.  I'll email you a test email and see if you can reply to it this week. 

As for the stem pieces, I had orignally cut them from 2 X 6 stock and this made them too thick.  Graham told me that my ultimate thickness should be 1 1/2", so I cut/planed them down to size.  The stem is now ready for glueing, which is my plan for today, as my epoxy/filler order is scheduled to arrive later this morning.  I'll get the stem and centerboard pieces clamped/glued and then I think I'll start working on my NACA foil cutting jig.  That should be interesting.

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Well, Travis, I can't answer for John, but for my part I've got a valid excuse.  My wife is out of town at a teacher's seminar in Galveston.  No adult supervision here.  ;D

It's tough, too.  The original plan was for us both to go.  I was going to try my darndest, somehow, to amuse myself during the days in Galveston town to be there to trip the lights fantastic with her at night.  Such visions I had of showing up at the tall ship Elissa with a can of varnish...

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I'll get the stem and centerboard pieces clamped/glued and then I think I'll start working on my NACA foil cutting jig.  That should be interesting.

Okay, that turned out to be a bad idea.  I've spent a few days figuring out how to turn a huge, glued-up chunk of wood into a NACA foil and I'm now scrapping that idea.  My original idea was to make a jig for my router, so I could have a straight bit follow a NACA curve and just elegantly remove any wood that doesn't look like a smooth foil.  Three jigs later, I had a test piece that looked like a beaver had been at it.  So, I toyed with just cutting a series of stepped cuts on the table saw.  I worked out all of the measurements and blade heights and then made a few dozen passes with a test piece.  It sort of worked, but would need a lot of shaping and cleaning work to ever be smooth.

Most disturbingly, it looked tiny.  I was amazed at how little wood is left when a plank turns into a NACA foil.  The thing just looks fragile.  The Core Sound and Lapwing centerboards I've seen look like they could smash into rocks and reefs and still keep ticking.  My test foil centerboard looks wimpy and almost looks like I could break it over my knee.  And, that's with a board width that is thicker (at the thickest part) than the original design.

So, I'm ditching the NACA foil idea and going back to the plan design.  I'm back on the Plantation.  Enough experimenting for this week.

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Drat.  I was hoping to steal your foil ideas.  I've built a centerboard for my CS17 but I'm going to build another.  No tears shed over the first centerboard, I learned about epoxy and planing, and a few things like that.  Version two will be a little less like Charlie Brown's Christmas tree.  I hope.  ;D

Last night I bought a jointer.  I know, gonna be hard to explain the hole in the credit card when my wife gets back in town, but I think it will be helpful in certain tasks.  Actually, I went to buy a bench sander, but if I bought just a little more I could get six months' no-interest.  Yeah, that's my story, I wouldn't have bought the jointer except it saved so much on interest.  :D

Anyway, making a precisely dimensioned stick of wood has possibilities, and my luck with shaping my first centerboard was minimal.  But, maybe I could shape the planks as a series of trapezoids and after gluing have a stepped shape I could just fair down with a sander.  I bet that sounds like way too much trouble, but maybe even with my minimal artisanship I could end up with a good, symmetrical centerboard.

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I made a little more progress this weekend.  I've now got the centerboard glued up and the outside shaped.  When I get home from this business trip, I'll start shaping the leading and trailing edges.  I'll be working freehand and I'm not exactly sure of the best way to tackle that shaping work.  Hand planes?  Power hand planer?  Belt sander?  I may have to just experiment.  The board is Doug Fir, so it shouldn't be too hard to work it.

Also, my Okoume arrived.  I didn't really have a good place to put it, so I built a rack along one wall of my workshop.  Now, I can store full sheets and cut pieces a little more safely.  

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I'll be working freehand and I'm not exactly sure of the best way to tackle that shaping work.  Hand planes?  Power hand planer?  Belt sander?  I may have to just experiment.  The board is Doug Fir, so it shouldn't be too hard to work it.

If you have a router... the general technique as shown in the Duckworks article here... http://www.duckworksmagazine.com/09/howto/foils/index.htm

should be useful. Many have reported good results with this type jig.

There is an alternative to all the math and spreadsheet work if you want a simpler approach - (1) 1st make a full sized pattern of your foil section from 1/4" ply or timber - (2) cut a circle of 1/4" ply with a radius equal to the cut depth you will use with the router - (3) stick a pencil through the hole in the middle of the circle and roll it along the perimeter of your full size pattern. You will now have the exact shape to use to make the router guide side pieces shown in the pictures of the article above.

Not my idea and I don't remember where I stole it, but certainly a simple and reliable technique for making router jigs of most any shape - without the math.

Hope that helps,

TomH

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Thanks for that tip!  My first attempt at a centerboard turned out quite horrid.  Good practice, I guess, but somewhere a fir tree weeps for the sad fate of her children, hacked to pieces and entombed in a centerboard not fit for firewood.  Oh, well, thank goodness for the privileges of being warm blooded.    :)

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I spent much of the day shaping #5's centerboard.  While I did rely on templates and paper patterns, the shaping was pretty much done by "feel".  I want to spend some more time with it tomorrow, to see how close to symetrical I can get it. I also want to put in some lead shot and a rope leading edge.

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