"Ken Grunke" wrote in message

Maxprop wrote:
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

Did you degrease the nut? Acetone or even just soap and water will do.

Yes. I degreased with acetone before and after scruff sanding the flats and
the underside with 80 grit prior to gluing.

Also, try undercutting the hole at an angle, just like a dovetail recess
for a scrollchuck.

I didn't do this, and it sounds like a reasonable idea.

Then grind some random grooves in the nut, where it
fits in the recess. Make the hole deeper even.

The hole was deep enough to completely contain the nut with no protrusion.
Go figure.

Max