snippage
Seriously, though, is anyone regularly bending 1/2" pipe when gluing
up tabletops or smaller casework? Iirc, the force necessary to glue
hardwoods together is about 250#/sq.inch, and although I can't
remember what the clamping force of 1/2" pipe is, I think it's
somewhere in the range of "a farking butt-load."


True that if our jointery is perfect, you shouldn't need much clamping
pressure. But what if you should screw up . . .er. . .I mean if your joints
are a little less than optimal? You just might need a farking but-load of
clamping force. Or if your wood has a slight twist, warp, or cup. Not
everyone can afford the luxury of thickness planers and jointers, etc., and
not all wood is flat and straight.

I cannot remember having 2' or 3' pipe clamps bend enough to be a problem
(using 1/2" pipe), but I have had 4' sections bend a little. And there are
even some possible cases where the bend can be beneficial. For exmple, I
was building a shelf unit that had dadoes cut in the sides and back for
shelves. When I used a clamp across the back of the carcass, it bent and
actually helped to keep pressure on the center of the shelf itself. In
other words, it made sure that the back did not bow outward away from the
shelf. But overall, I would say that the stiffer the clamps the better so
go with 3/4" pipe.

Wayne