On Sun, 16 Dec 2007 09:16:58 -0800, with neither quill nor qualm,
"SteveB" quickly quoth:

I have a very old turnbuckle. One rod came out, luckily the one that is
threaded in the reverse direction of a common bolt, so I'll be able to get a
3/8 common turnbuckle piece to replace it if I ever get it out. I managed
to twist the other one off. Now, it is down to a nub I can just barely get
hold of with Vise Grips. I heated it a couple of times yesterday and
dripped 3 in 1 oil in there and let it cool. I still can't get the thing
out. Trouble is, the long end is between the two forks of the turnbuckle
and inaccessible. I can drill a hole sideways through it, but don't think I
can put enough torque on it to get it loose. Any better penetrants?
Methods? Or am I going to have to carefully drill this out? I'd like to
save it, as it is somewhat of an antique.

Spray liquid freon (or other chiller spray) on the threaded section,
immediately apply pinpoint flame to the turnbuckle at the joint, spray
the threads with Kroil, and then turn. Be sure to use some aluminum
anti-seize compound on the replacement.

--
Seen on a bumper sticker: ARM THE HOMELESS