and therein is the problem. <img src="http://www.catsailor.com/forums/images/graemlins/frown.gif" alt="" />

There are proprietary stain removers that will remove rust. Oxalic acid will also do it. But I think you'll find they'll all take the colour out of your sail. Is it REALLY bad or could you live with it?

At some point in the future you'll be getting new sails, if it were me, I'd just live with it.