What most of you guys are calling "silver" solder is probably just the run of the mill 60/40 stuff you can buy at radio shak. Real silver solder (such as the kind typically used in plumbing and so on) usually takes the heat of a torch to get good flow with. I've never had good luck with any kind of iron or gun with real silver solder. However, using Rosin core solder is plenty good enough for our models, and a gun or iron will work great with it. Sand, clean, flux, and heat--apply the solder and let it flow. The key is good heat, and apply the heat away from where the solder will be applied, and let the heat "draw" the solder into the joint--this assures a good strong joint.

All I use is a gun. I have a dual wattage "station" that I hate. Takes forever to heat up, and doesn't work worth a crap for soldering clevises--my 100 W gun works absolutely flawlessly.