You could always drill a hole in the back barrel and fill it with
the plastic - and solvent. Melt the rod/hole into the threads
by melting the small rod.

Martin

On 5/13/2015 9:27 AM, rangerssuck wrote:
On Tuesday, May 12, 2015 at 2:06:34 AM UTC-4, snafu wrote:
On 12-May-15 11:23 AM, Steve W. wrote:
snafu wrote:
I have a 1/2" x 20 UNF bayonet style electrical connector threaded
into PVC.

The PVC is the standard gray material bought as a round bar off the
shelf.

Mechanical constraints prevent using a locking nut or radial set screw
for retention.

Does anyone have any suggestions as to what chemical means might be
useful to lock or bond the (probably stainless) metal connector to the
PVC to prevent unscrewing?

Thanks.

Take the connector out. Mill a slot up one side to half of the depth per
width (1/8" wide slot Mill 1/16" deep). Install the connector and use a
drill bit to "transfer" the slot to the PVC and finish the hole to size.
(1/16" in the connector 1/16" in the ABS). Now take a chunk of PVC
welding rod or ??? that is 1/8" and apply some PVC glue and insert it
into the hole. Once it cures the connector won't move.
Basically a linear locking spline. Same idea as used on key lock thread
inserts. However instead of using the steel pins those use you have PVC.
That way if you ever did need to remove it you could heat the connector
and turn it to shear the PVC spline.



That's a great idea but there is likely to be 1000 of these made (I
should have mentioned that earlier). I'll save the idea for next time
I've got a use for it.

That IS a great idea. You could also
1) score the threads on the connector with a mill, a dremel wheel or even a file - just rough ' em up.
2) make the hole in the pvc just a little bit tight.
3) Apply a PVC solvent cement to soften it a bit, then screw in the connector.

The PVC ought to deform into the score marks.