So the storm a couple of weeks back snapped the link between the boom and main sheet on out boat - an easy enough replacement except the bolt that attaches those two plates to the boom is well and truly jammed. Trying to undo it so far has just resulted in gouges in my wrench. I tried some liquid wrench today too but that didn't help.

Anyone got some ideas on how to get this bolt out? Or other ways to attach the main sheet to the boom?

Picture: http://www.flickr.com/photos/ciaran-sf/4062915974/