I realize there are scads of people today who will compare what I'm about to say to using an outhouse but give me an oxy-acetylene rig and silver bearing solder any day. It melts at around 400 degrees, makes a joint as strong as goat's breath, won't cause your panel to warp and can be re-done infinitely. Plus the solder can be dressed in about the same fashion as lead...and the learning curve of the stuff is short and simple.