C-34 In-mast Furling Line

[crimmins]

I have a 2003 Catalina equipped with in-mast furling. I would like to replace the in-haul furling line that is attached to the continuous screw (furling) drum. I've just discovered that the bolt that holds the line to the lower end of the drum has either been overly tightened by the boatyard that commissioned the boat and/or that corrosion has frozen the bolt in place. In either event I can't loosen the bolt. Does anyone have suggestions as to how I can get the bolt loose without risking damage to the top of the bolt, which would compound the problem?

[Jon Schneider]

Keep dowsing it in PB Blaster for a week, then heat it with a little torch; let it cool and then apply torque.  If you can reach in with an impact driver (I don't have an in-mast furler, so I don't know how much room you have to navigate), that'd be the way to go.