I cut my first ring of GFO packing too a bit too short so I decided to
abuse it. I wrapped it around a 3/8" stainless steel bolt chucked into
an electric drill and then clamped it in a vice. With the drill going
full speed, I tightened the vice to see what would happen.

The drill never slowed down. A small amount of black liquid started to
ooze out of the packing and along the bolt. After about a minute at
full pressure, the bolt got too hot to touch. The packing ended up
about half it’s former thickness but otherwise appeared to undergo no
physical change other than the soft and smooth aggregation of
lubricant at the running surface. It was softer when warm but still
about the consistency of the green putty style dripless packing I’ve
seen as an alternative.

On the first trial, I accidentally wrapped the packing around a
portion of the bolt with wrench mark burrs. These didn’t seem to faze
it or create any shredding.

This looks like incredibly rugged stuff that should stand up to far
more than stuffing box service could throw at it.

--

Roger Long