Hi guys, I'm having some problems with the threaded valve connections on a bathtub install. It has a total of 5 threaded connections....all are female copper to brass connections except one. The male threaded copper connection to brass is causing me the most problems. 1. Can this connection be soldered? 2. Can any threaded connection be soldered???? 3.Should I purchase a brass threaded connection and try it with joint compound? I don't have enough room for a union. I'm pulling my hair out here.....please help!!