Door hinge dismantling

[SimonS1]

I'm having trouble getting the door hinge bolts to unscrew from the bobbins and I can't see this problem in previous threads about the hinges.

I've got both top and bottom bolts to turn but they don't rise/fall, they stay at the same height. I've tried putting an open ended spanner around the exposed length of the shank (see cutaway below borrowed from another thread) and used it to lever the bolt up while turning it with a socket. It keeps turning but refuses to rise. Any bright ideas on how to get it out?



This is puzzling me as I can't work out what the cause is. If the bobbin has come loose I'd expect some play in the hinge, but there isn't any. If the thread has corroded away then I'd expect the above levering and turning to extract it, but it doesn't.

[SimonS1]

Thank you both for those replies. I was hoping to avoid cutting the bolts and bobbins out due to the fibreglass damage it's bound to cause, but it seems to be that or leave the doors on. I'd not found that particular thread before, thanks magpies.

I know there's a lot more activity on the FB group these days, though I still look here for detailed technical info.