"igor" wrote in message

Caveat: I say all this having used neither a jointer nor one of these
high-f'luttin planes some of youse guys have. I'm just trying to follow
along.

You're right, nothing is ever perfect (and the more expensive the wood, the
less perfect it is, particularly when you're on the last piece). But, if
done properly, the described method will give you "perfect enough" results
than you would get by doing the edges one at a time without some stable, and
repeatable reference, preferably perpendicular to the edge you're preparing.

Assuming the faces of the stock are parallel, the idea is to insure that the
joined edges, if not precisely 90 degrees each, are at least
'complementary', in that they add up to 90 degrees.

IME when planing with this method, which is limited, it works best when the
thickness of the two pieces clamped together is less than the width of blade
doing the cutting, so that both edges are cut all the away across on the
same stroke.

Actually, you don't even need to go out to the shop to see the principle in
action. Grab a piece of paper and scissors and cut out two virtual
tubafours. Lay them on top of each other and snip one end off with the
scissors, either straight across, or at a slight angle. Now join the two
snipped ends and they should match.

You can do the same thing on a jointer, and remove any small error in the
fence being 90 degrees to the tables, by alternating good-face-in,
good-face-out, when jointing for long grain edge to edge glue-ups.

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Last update: 11/06/04