splicing in a tip on a fire spindle

Anyone have any luck with splicing in a tip of suitable material to spindle for either bow drill or hand drill fire sets? I'm thinking of the case where you have a spindle that is either too green or just not a good fire making material but its the right size and you have a bit of something which would be good for fire making were it not too short. I've heard people talk of grafting them together but haven't seen a really solid example that includes a picture or description of good ways to lash the thing together so it doesn't fall apart.

The two general suggestions I've come across are to use a half-lap joint or to split the end of the spindle, wedge in the tip and tie (no details given on that part) around the outside.

Thanks
-Dan

you can get a good scarf by cutting both pieces to a sharp angle [which should hold better than a half lap]:

http://www.rabbitwoodworks.com/image...carf-joint.jpg

and then lining them up and lashing tightly with fishing line, natural or synthetic cordage or even a simple bark fiber. many natural fibers shrink as they dry out, and will secure the hold as they cure. using such a scarf ensures the joint holds tighter the more downward pressure you subject it to, as both pieces become wedges, and all the better if you can glue it up with an adhesive such as glue or a thermoplastic material such as resin/pitch, or even melted plastic.

for example, if you bind it with paracord, nylon rope, etc, you can lightly flame the binding and as it melts, it will heat weld and have a more secure hold.