I misplaced my roll of solder for electronics. I dig around and find an old half roll of Fry solder from PA. It is pretty small gauge like one would use for electronics, but has no ID on it to say what it is. I thought most all small gauge solder was for electronics (rosin)??? No? It is a little dull looking...but still can't find my other roll. Have no idea where this roll came from, was in some stuff given to me. Is there any way to tell?