On Tue, 19 Jul 2005 16:29:57 +0100, "flash" wrote:

I do have some thick timbers but they
are all three foot long, so what I want to do is join them together somewho
to make six foot posts.

Personally I'd find some new timber, long enough. The joints are too
much trouble.

Obviously you're hard-pressed to get six foot from two three footers,
unless you use a butt. That's not a bad way to do it, if you use steel
plates bolted on from either side.

A scarf is inappropriate for a vertical post. it will also lose the most
length. If you must, it needs to be a more symmetrical birdsmouth
(either halved or cornered) scarf, rather than a simple scarfed lap. You
could also use some form of stubbed scarf. None of these are easy to
cut.

Perhaps the best joint is another Japanese joint - jyuji mechigai tsugi
- the cross-shaped mortice and tenon. This is good from locating
verticals and it's also easy to cut. One face has a cross cut into it
by removing the four corners to leave a cross with arms about 1" wide
and 1" deep. The other is cut to leave four castellated areas with two
grooves between them.