scarf aesectics


Hi started a wood duck12 & have scarfed 2x sheets ply for  strakes- now trying to figure out whether the scarfs should all line-up to form a continous seam when the strakes are stiched together or whether they should be "staggered" - my reason for asking is not a structual concern but rather an appearence concern  - that if they don't lineup on the finished boat it may look ugly - any thoughts???

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RE: scarf aesectics

For structural reasons, I'd recommend staggering them.

Remember, it's a boat, not a coffee table!

RE: scarf aesectics

The puzzle joints on the WD12 kits and the scarf joints on the Chesapeake series are staggered and none of them look ugly (you can browse the various ad pictures and see if you agree).

Jim is absolutely correct that structurally it's not a good idea to perfectly line them up. The closest I've seen any CLC boat come to that is the NE Dory with its pseudo-continuous puzzle joint, but even there the joints are spread out.

If you're really concerned about looks, it's possible to make the scarfs so tight that they'll look like a thin pencil line. I've never thought it was worth the trouble myself, but some of the master builders on this forum have managed it. That'd be a way for you to address the aesthetics and still be structurally safe.

Have fun,



>>>>>>Jim is absolutely correct that structurally it's not a good idea to perfectly line them up. >>>>>>>>>

It's a fact that scarf joints are stronger than the surrounding wood.  If you line up the scarf joints, it's as if you've put a thin rib in the boat right there.

Besides that, scarfs end up buried under fiberglass in these stitch-and-glue kayaks.  To a considerable extent the wood ends up being core material to the fiberglass skin.  So where the scarf joints land really doesn't matter.  That's why we're happy with butt-joints and puzzle-joints some boats, which aren't as strong as scarf joints. 

The best policy is to not pay any attention to where you put scarf joints in stitch-and-glue boats.  Let them fall where they may.

Years ago I caught a prominent boatbuilder advising builders to orient scarf joints in plywood so that, as the water moved past the hull, water couldn't be "caught" in the scarf joint like wood in a block plane.  This on boats that were being fiberglassed.  Complete bollocks!  If you need water pressure to hold your scarf joints together....

Before there was epoxy, before there was marine plywood, when you were "scarphing" or butting planks on a traditional boat, then the joints were weak and the weaknesses had to be strategically scattered around the hull.  Completely off the radar in this century. 




RE: scarf aesectics

thanks fellas for input - shall stagger scarfs much easier to let them "land where they fall" - this was advise of my father (retired boat-builder) but what son listens to his father - mind you this morning he told me NOT to bother about a bright finish says "putty & paint can fool a saint" - no way

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