Dave Hinz wrote:

On Sun, 16 Dec 2007 09:16:58 -0800, SteveB wrote:
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.

Kroil is the best penetrant I've ever used. I've also heard good things
about LPS's product but haven't used it myself. LPS may be easier to
find depending on your location.

Yep, Kroil is great. I ordered a gallon based on recommendations here
and I love it.