Most likely the "silver wire" you have is "tinned" copper wire. You should be able to find some solid copper wire and use it for the rest of your joints. You might even be able to get some tinned copper wire. It will get "tinned when you solder everything together. The galvanized wire will not work to well. The main purpose of the wire wrapping is to hold everything together and to form a matrix to hold more of the solder in and around the joint, while you are soldering it together.