DIY universal charger, several pieces of iron, how to weld with 2W soldering iron, it's really impossible to weld!

2w welded iron sheet is estimated to be a tragedy. I'll give you a parameter

The thinnest 14th iron wire with a diameter less than 1mm, and a 25W electric soldering iron is enough.

the thickest No.8 iron wire, with a diameter of 4mm, needs more than 1W to be welded firmly.

I suggest you drill a hole in the iron sheet. If you don't drill it, nail a hole and thread it in. It should be strong. Good luck