Insert solder wire into the rolled bead and then bend. You can also use <a href="http://www.canadametals.com/pdf/cerro_bending.pdf" target="_blank">cerrobend</a> or it's equivalent like woods metal and then heat to water boiling temps and melt it out later. You could also use stainless wire and leave it in there?
The best way is to use a beading roller and then roll the bend you want. Most sheet metal shops will have a tool like this.