cutting splices with hand tools

[vinemaplebows]

I concur that Z-splices with hand tools are pretty tough for the unexperienced...
Simple V-splice does the trick for me, at least on my last bow (which is around 40#). After the glue has cured I drill two holes and add round plugs to secure the splice.

Why? If the glue isn't going to hold, drilling holes in your splice is not going to help.

[Hamish]

Cutting splices by hand:
It all comes down to accurate marking out, and good quality tools.

The sides and belly should be planed flat and squar,. Not easy if you don't have the tools or experience.
Mark the splice on the back . The flat and square surfaces allow you use a combination square to project accurate lines around the sides, to the belly. Mark up the lines belly and you will have identical sets of lines on both back and belly.
Mark out waste area on both sides of both billets and double check that the correct areas will be cut.
 
Cut from both sides rather than sawing from one side and hoping the cut will stay square. A spliced handle is going to be 1.5 to 2" deep, from back to belly which is too much for most people to cut accurately with a handsaw.
When you cut from  each side you first saw to the other side only at the top, then down the handle staying on the same side, the blade doesn't go through to the other side  .  Then flip it around and repeat. This leaves a hidden peak of material in the middle which you then cut. The billet now has kerfed partial depth cuts on both sides so sawing down the peak is easy as the kerfs guide the sawblade from one side to the other of the billet.

You need a good saw, either a very large western tenon saw rip cut teeth with a back on it to stiffen the blade. You will need one the allows at least 4.25" depth of cut. (expensive for a new one)
Better off getting a Japanese pull saw, with rip cut teeth, as they don't need a blade stiffener, so they can cut 4"depth no problem.

If you don't have any experience practice on some scraps, both squaring up and cutting.
Hamish.

[Drewster]

I completely agree with Hamish about the accuracy of your joint being directly related to how accurate you lay it out.  I square up two surfaces like he does whether I'm going to cut the joint with a band saw or by hand.  You are "dead in the water" if your joint isn't accuracy laid out not matter how you cut it.
I use a knife point to lay out joints too, not a pencil.  A pencil is too wide and just not precise enough. 
Practice and pay attention to the little details. It will improve all your woodworking skills.

[russell]

Good info Hamish - very well explained.