I have some of each. Got the 1/2" when I was young and broke. I still
find uses for them from time to time. Unless the above description fits
(young and broke) you can use a 3/4 for anything you'd use a 1/2 for but
not necessarily the reverse. I picked up a few 3/4 sets from Rockler a
while back that have the bracket on the back that keeps the jaws level.
I also have a few bar clamps of various types. Have you been thinking
about Besseys? Pipe clamps have the advantage that in an unexpected
situation you can use very long pipes, you can use couplers, you get the
idea. A few are always nice to have around. Other things being equal,
I'd go with the 3/4.

rhg

Robert Rushing wrote:
I'm in need of some clamps. I was looking at pipe clamps and have a few
questions. I will be gluing up a small cabinet and need atleast six clamps.
Working in the 36 to 48" range is 3/4 pipe clamp necessary are will a 1/2
work ok? Also HD had some I frame Jergenson sp clamps 36" that are
competitive with buying pipe and ends for pipe clamp. Are the I frame
clamps sturdy enough to glue up a cabinet with I have never used them
before? I have read that the Bessy clamps are best but at $37 and needing
six they will have to wait.

Thanks
Robert R