I saw this neat little trick at a demo given by Cynthia Eid regarding soldering on an earring post. The key is to making this little tool and heating the metal up indirectly. She used 20 gauge binding wire that was forged into this shape. You forge it so that the grippers are flat. They have to have enough tension to grip the earring post. The post is placed into the tool with only the top of the post being held. On a charcoal block, you direct the heat in a circular motion from say from a 2:00 position to a 10:00 position around the outside of the metal. The hardest part for me was just getting the tool made correctly. If the tension is too tight, the wire will slip out to the left or right depending on the grippers. But after a few attempts, it worked! The solder I used was pretty thin and you only need a very tiny piece.