Some additional comments- the biggest problem people seem to have with soldering is getting the parts hot enough. You will have to get the coupler very hot in order to melt the solder. I put the wire in a vise and slide the coupler on. Then I hold the red-hot part of the soldering iron tip against the side of the coupler until the solder melts. If you have problems getting the solder to melt then you might need a hotter iron.