How do I cut a hooked scarph joint

[Erik Nyren]

Hello
 
I was wondering if anyone has any tips on how to cut a hooked scarph joint in an easy way, is there one??
 
Of cource one can easily simulate such a joint while planking using a pencil or a small blade but I would like to make the real thing.

Help please
 
Erik

[allanyed]

Erik

I normally cut one piece then lay it on the second piece and with a sharp point, mark the matching line. Cut short of the marked line, test fit, then trim with a chisel or other sharp blade and test fit again and trim and test until it is a perfect fit. It is easy, albeit takes a little time and patience.

Allan

[figuerres]

I think the correct spelling for that is "Scarf"

 

I can not say that I have done this but I would start by stacking 2 planks and cut the as one then flip one around and they will match up, that will be part of how to do it.

 

I would probably start with a simple miter angle / diagonal cut then snip or and off the end for that part.

 

then carefully cut out the "inset" that makes the "Hook" catch.

[jml1083]

Hi Erik

 

Here is one possible way.

 

 

The first thing I would cut are the red lines which seem to be vertical. I would cut them on my table saw.

 

The angle of the green line can be found by placing a large shim under one end so that the green line becomes horizontal. Hot glue the shim in place so that it doesn’t move but is easily removed once you are done. Once you have found the horizontal raise the table saw blade so it cuts to the deepest part of the joint. Make repeated passes over the table saw blade moving the piece slightly to the side until the dark gray area is removed. Do the same thing with the adjacent dark gray area on the same piece.

 

Once all of the dark gray area has been removed I would use files and sanding sticks to make sure the bottom of all cuts are flat and square to the sides of the wood. Then I would lay this finished piece on its mating piece and trace a very fine line following the outline of what was the red and green lines. This will give you an exact template of what needs to be removed. Then just remove the stock in the same way.

 

I would use an auxiliary fence to support the wood as you are running it over the blade. Needless to say I'd keep my fingers out of the way.

 

I am sure there are other ways to do this as well. I hope this helps.

 

 

[druxey]

Allanyed's response is a good one. A very sharp pencil (hard lead is best) and accurate mark-out are the critical parts of the operation, as well as a sharp chisel. 

 

By the way 'scarph' is the correct spelling; 'scarf' is the thing you put around your neck to stay warm!

[Erik Nyren]

Hello

 

Thanks for the guidance, having read your answers I started to mess around with some apple strips.

From my plans I could find that the joint is 20mm so I messured out a diagonal through 20mm on a plank

 

Then I cut the strip on the table saw and rubber glued (gummi klister) the two pieces together. A bit of sanding on a disc sander to ensure a perfect surface.

 

Then I marked the middle of the cut, set the table saw blade on a 1,5mm hight and started to cut out a notch.

 

Separating the strips and well nothing less than magic, I had two fitting strips

 

Very little sanding was needed to fit the parts resulting in a joint that was actually har to see

Believe me I was surprised !!

 

I then tried to use a bit of black acid free paper for chaulking, it weakened the joint but made it visible. I will not use paper on my actual ship as that would make this particular joint scream out from the rest of the planking.  

 

[Remcohe]

Very nice Erik, once you understand how to make them, it's not as hard as it looks

 

Remco

[figuerres]

Nice!!   a lot of carpentry cuts work with the "mirror image" trick in a few variations....

[SJSoane]

Here is a jig a built a while ago to do hooked scarphs. It allows adjustment for different lengths of scarphs.

 

Mark

 

[mtaylor]

Nice work and nice tutorial.   Thanks to both of you.

[druxey]

Neat method of doing this with power equipment.