I'll almost gurantee that you are distorting BOTH the bushings them
selves as well as the alignment between the bushings. If your 'bushings'
are really thin tube, double that.

You might want to experiment with just one tube, use your rod through
the center, weld on one side, pull the rod out, measure the resulting
inner diameter. Expect to find the tube egg shaped in the .030" range,
and bent by .020"to .050" over a couple of inches.

If things are critical, you will have to consider boring, reaming or
drilling after welding.

Max Krippler wrote:
Hi,
Is there some compound or liquid that I can spray or rub on between
parts that will keep them from fusing from the heat of nearby welding?

I'm welding three pieces of tubing to a structure, and they have to
line up precisely, so I've got to have a shaft holding them in place.
The problem is that the heat causes the shaft to get stuck. I don't
think that I'm welding through the side (I'm quicker than that) but
something is fusing it in place. Any help for this?

Thanks, --Max