"Gunner Asch" wrote in message
...
On Thu, 18 Aug 2016 17:27:26 -0000 (UTC), Doug Miller
wrote:

...
The stuff compresses enough for the vibrations to move it. Put a
wrap
of carpet tape on it, or wrap it with the old cloth electrical tape.
Or.....turn a piece of wood until its a SNUG fit in the bore, slip
it
into the pipe, chuck it up and cut it off.

The simple way to do that, since the tubing ID is difficult to measure
exactly enough and it may be distorted, is to turn a plug close to
size, file the end tapered until the (deburred) tubing will jam onto
it, then touch the lathe bit to the mark the tubing left and turn the
larger end to that size. The grooves and ridges from turning or coarse
filing let the plug compress and adapt to the tube somewhat. You don't
want the plug so tight that you damage the tube pounding it out.

On my old lathe the plug may need to be supported by a tailstock
center to keep the diameter constant enough for a light press fit..

--jsw