Quoted from radfordian3505:What soldering iron and solder did you use bc mine is soldering the lamp sockets great but im having a hard time doing the ground braid to the sockets.it seems like it wont get hot enough
Might not be the issue, but try to avoid lead free solder. It works, but has a higher melting point. Definitely not as easy to work with as 60/40 or 63/37 lead solder with rosin. Don't use plumbers rosin, it's very corrosive (i.e. not electronics friendly).
Answering your original question - I would think a 40W would be fine. Might want to get a chisel tip (i.e. wide) to help xfer the heat.
