Having adopted Andrew Hilton's method for honing tools between sharpenings,
ie--fining them on a disc made of MDF with a 6" PSA sanding disc attached to
one side and a method of attaching it to the spindle on the lathe on the
other, I've run into a snag.

I used a 3" faceplate on my first such disc, but tried a second method of
attachment after someone suggested this: turning a partial-thickness recess
on the back of the MDF and gluing a nut (1x8 in this case) in the recess for
attachment to the spindle. After two attempts at this, it's been a failure.
In both cases I turned the backside hole slightly undersized for the nut,
then seated the nut into the hole with a brass mallet while gluing with
gap-filling cyanoacrylate adhesive (super glue), and then applying a fillet
of epoxy around the flats of the nut to fill the gaps between the nut and
the hole sides. I even scruff sanded the flats on the nut to bond to the
epoxy better. In both cases the nut eventually popped out of the hole,
sending the disc flying. I was not honing a tool at either time, and the
lathe was set to its lowest speed--roughly 450rpm.

Any ideas as to why the nut won't stay in the hole?

Max