6" pole barn spikes driven with a 27oz hammer hold very well. --dave

"Geoff" wrote in message
ups.com...
Straighten the edges with a jointer plane. Takes some technique, but
that's the way they did it in the old days.

Start with a table saw to make sure both edges are as straight as
possible. Then clamp both boards together and plane both edges at the
same time. But they have to be STRAIGHT.