[Reece]

What you need is a lot of heat fast. Watts aren't necessarily the answer. I have a dual heat Weller and other irons but the one I call on for heavy work, not that often, is an American Beauty soldering iron that I got for a buck at a flea market. I think it's 150 watt. The thing is to plug it in for several minutes and let it heat up all that mass of steel and the big copper slug of a tip that extends deep into the heater. Then when you're ready to solder, all of that stored-up heat, much more than 150 watts, is available to pour out into the work. There's a bigger contact area with the iron and stored heat, more than just the instantaneous electrical rating of a gun.