I bought a new soldering iron I needed for a class, and I wanted to practice a little before I went. Well, it worked great until I wiped it off with a wet towel and ran to home depot to get a clamp to hold my work. I came home, plugged it in, and the dern thing wouldn't hold the solder! It just dripped off. Then, it stopped melting it all together. Um... any experienced stained glass artists or plumbers have any ideas???