View Full Version : Scarf jig?

Chris Stevens
02-06-2001, 05:09 PM
Someone mentioned building a jig for cutting plank scarfs...has anyone made there own jig (I'm cutting 12:1 in 5/8" pine), and could enlighten me?


Dave R
02-06-2001, 05:24 PM
I built one so that I could cut scarfs with my router.
It was pretty straightforward and only took an afternoon to build making it up as I went along. It seems to work pretty well but it won't handle anything wider than about 12".

If you want more info let me know. Good luck.

J. Dillon
02-06-2001, 06:43 PM

Looks http://media5.hypernet.com/~dick/ubb/cool.gif How do you keep your shop so clean ? http://media5.hypernet.com/~dick/ubb/wink.gif

Dave R
02-07-2001, 08:20 AM
That was before starting on the boat when SWMBO insisted that the cars be kept in there and that we call it a garage.

Thanks for the compliment on the scarf jig, too.

In case anyone is interested the thing on the top of the router is not really related to the scarf jig although it helps.

I made that simple attachment to allow the router to be adjusted when it's in the table. I found that trying to push the router up bent the insert making it impossible to get a n accurate measurement. It uses the existing holes in the base and the center rod is 3/8-16 so one full turn of the knob moves the router 1/16".

Ed Harrow
02-07-2001, 08:49 AM
Geez, I remember when our garage looked as clean as that... At least we can still get them all in.

There are several sources of plans for scarf jigs for routers. I think WoodenBoats collection of planking articles has one, as well as does Bruce Binghamton (SP?) Practical Yacht Joinery (or close). There maybe a couple of others, Bud McIntosh, Jim Trefethen are other authors I have in my collection, so possibly one of them. I'd take a look but the books are a long way from where I am at the moment.

02-07-2001, 11:09 AM
Dave R's scarfing jig looks very useable, as are the others mentioned by Ed Harrow. I like to rough out the cut first on a bandsaw, or for narrow planking on a table saw, then put it in the jig for smoothing with the router. Purists will say that a hand plane is sufficient for the smoothing, but it's easier to get a matching pair for the scarf with the router & jig. A good alternative is to use a hand plane with a jig.

As for working in your garage, you've heard it before: Why would anyone want to park his car in his boat shop?

[This message has been edited by Bayboat (edited 02-07-2001).]

02-07-2001, 05:28 PM
I scarfed some wood not too long ago using a No. 7 jointer plane and it worked extremely well. I was scarfing 10:1 on 3/4" mahogony so I clamped a piece of 3/4" pine 15" back from the end and just kept the plane resting on the corner of the pine as I cut away the mahogony. By the time I got down to the feather edge, I had the perfect angle and width (wish I could put in a diagram). All you need is a No. 7 jointer plane. Mine cost $120 so I'm glad I found a good use for it.

02-11-2001, 10:19 AM
The router jig will work fine, but you don't really need it. I rough scarph joints on the band saw or with an electric plane if the bandsaw table is loaded with junk (no immaculate shop here) and finish with a block plane. That way you're developing hand tool skills, and don't have to find that scarphing jig that you carefully misplaced the last time you used it. But that's just me.

11-27-2001, 06:17 PM
Glad I found this forum ...Thankyou..Sincerley....Thankyou

11-28-2001, 03:27 PM
I routed my plywood strake scarfjoint too (finishing with a low angle block plane). How do you acheive a crisp streight edge on the feathered end? My scarf joint are the raeson the boat is being painted instead of varnished.

11-28-2001, 09:39 PM

WHen I was scarfing 1/2 marine ply, I would extend the scarf a bit, but I would leave the last layer intact, I would not scarf all the way to the edge.

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something like this. It took me very long time to do it (relatively speaking). And I finished it with a random orbit sander to achieve the final result.

11-28-2001, 09:40 PM
Crap...the pic didn't come out right...


11-29-2001, 11:44 PM
Here's our jig. A lot less advanced but it worked all right.
or http://geocities.com/sigvardsenstudio/faering/hull/hull.html#06

BTW isn't a clean shop a bad sign?

[This message has been edited by Kristian (edited 11-29-2001).]

Charlie J
11-30-2001, 12:26 AM
Ed- Practical Yacht Joinery was written by Fred Bingham. He's Bruce Bingham's father.

12-03-2001, 09:04 PM
I'm trying my first attempt at scarfs on some doug fir stringers out of 1x8 stock. I took a metal ruler, put the corner on one end and the twelve diagonally across and traced a line. Cut em freehand on my bandsaw, and they look pretty straight. Course this is not finish work I am doing. First two are glued up now, I''ll let you know how they hold. But on thin stock like this, it may not be necessary to spend time on building a jig. I may eat my words tomorrow... http://media5.hypernet.com/~dick/ubb/eek.gif