True, true, Mr. Conroy---
 Do not despair, galoots, if it's wood, it's always moving, and different pieces
move at different rates.
   I'd try a week or two in the dryer you use for chair-legs and trunnels. If
you don't already have such a thing, it's a top-vented box with a hot light bulb
in the bottom, at the intake vent.
   As your patient warms up under the hot lights, try loosening day after day.
One should also try tightening: The contact surfaces in stuck screws are almost
always  'trained' for tightening. Once budged, it's much easier to reverse
direction.
  Applying high frequency vibrations, by hell-beating with a hammer, is
sometimes in order.
  If your subject hasn't come apart after a few weeks of desiccation, move out
of the dryer to a moist environment and try the same persuasions for a few more
weeks. If it hasn't come apart by then, bronze it, and send it to some galoot at
Christmastime.

                                and a very happy 3rd of July to all galoots
everywhere; gam in OlyWA/USA
    PS---Apropos of nothing much, hammer-drills from concrete borers on down to
the modern hideously loud impact-driving screwguns can drive nails, settle
concrete in forms---or shake the letters off a printed page---with no traces
left behind---if cushioned properly. YMMV

"If you were Einstein's father, there wouldn't be a bomb."  Peggy Hill, ca. y2K 

    On Wednesday, July 1, 2020, 02:07:32 PM PDT, Thomas Conroy via OldTools
 wrote:
 
 Scott wrote: "Wooden screws can sometimes be impossible.
Its sad, but its a fact."
Correct as always. Don't despair, though; remember that wooden screws expand and
contract with changes in climate. Sometimes they are frozen at one end of the
year but loosen up at the other. Checking it once a month for six months may get
you to the sweet part of the year. Sometimes they freeze when going from one
kind of heating to another. That can be trickier to diagnose, but not so
difficult to treat, if you allow for time to acclimatize to a better climate.
(but remember that a wooden screw can freeze up either by shrinking or by
expanding).
Tom Conroy