Martin Eastburn wrote:
Seems like a Delrin rod that was cut to 1/2 diameter with a
cutoff tool - every 1/2" or more or less - would provide some
give in a bend but would hold diameter. Pulling out from each
end might be logical - perhaps breaking a joint and freeing
the curvy bend. The smaller diameter is a temper fuse :-)

Martin

I was using a home made rotary draw bender for the job I did and was
bending the tubing to a fairly tight radius using a former I already had
made for some solid bar. I found the solid nylon worked fine without any
cuts and was fairly easy to remove when pre-lubricated. I think cutting
it might make the bending a bit easier but might also lead to the nylon
breaking on removal and making removing the remainder a bit of a pig. In
my case I just grabbed the nylon bar in the vise and grabbed the bent
copper tube and twisted and pulled and the nylon eased out of the bend.

On 10/9/2011 4:08 AM, David Billington wrote:
Steve B wrote:
I have some 3/8" copper tubing that I need to bend at a tight radius.
Like 2". I have the spiral bender, and another hand held type, but
can't find either. Next week, I gotta get organized. In the meantime
what's the best way to bend it? I've heard of putting it full of sand.
If I do that, do I bend it around something round, or just bend it
slowly and cautiously?

Steve

I bent some 10mm copper tube recently into a tighter radius and used
some nylon rod I had about inside the tube. I do have Cerrobend but
didn't want to use it at the time. The nylon was just slightly smaller
than the ID of the tube and after bending I could grip the rod in a vise
and twist the rod out without too much trouble, the subsequent bends I
lubricated the nylon which eased removal.