Flat Draw Knife.
They cut and split faster than you think. Could pre-shape and finalize.

Martin

wrote:
I'm putting up a split rail fence and am near the end of the project.
I tried to plan the project to use full length rails for the majority
of the fence run but I have about 5 locations where there must be
shortened rails. The rails come as full 4x4's - they actually measure
4" x 4", and the ends have 2 tapers on each end that form the tenons.
The oddball thing is that the tapers are cut across 2 faces so that
when the tenon sits in the mortise, the rail is situated where you see
2 faces of the rail, as if it's sitting on one corner, and not a face
- it's sort of discernable in the upper left and lower right rails of
this pictu

http://allstarfencedeck.com/yahoo_si...210453_std.jpg

Now, my question is, I need to cut several of these - how to? I've
tried a chainsaw and it is not very good at making tapered rip cuts.
I've also tried: scrub plane, handsaw, circular saw, recipro saw.
Mostly I'm making long hacked up toothpicks - Ha! Remember that not
only do they have to be tapered, but the tenons have to be in the same
plane as each other from end to end, in order for the rail to fit
correctly. Also, the rails are not always straight & mostly aren't.
Wit's end here!

Cheers