Lab: Soldering Irons

Legal disclaimer: This info is based on 50 years of experience with soldering. However, I assume no liability for errors, omissions, burning or blowing up your project or yourself, or your home, or any monetary loss or other creative mishap.

I mostly work on older vacuum tube and solid state equipment (pre RoHS) so I still use tin/lead solder and older soldering stations.
My preferred soldering tool is a set of Weller WTCP soldering stations. These have been around since the mid 70’s and have proven to be a reliable and durable soldering tool. The WTCP stations have a good temperature regulation system, grounded tips (so static sensitive parts don’t get blasted), they’re easy to maintain and repair, and parts are readily available used on eBay and the like. Tips are still available new and last for decades.

You will likely need a variety of tip sizes and temps based on the task at hand. (I have multiple stations so I don’t have to swap out tips during a project.)
The one on the right has a heavy duty 800F tip, the middle has a standard 700F chisel tip, and the left has a very fine point 700F tip. These temps and tips handle most of the situations I encounter in a project, from soldering 12 gauge wire to tiny pads on PC boards.

Lineup of Weller WTCP soldering stations. Note the sophisticated gaff tape on the handles, that helps prevent the wires in the cable from breaking.

Tips on soldering

  • SAFETY A: Yes, this is real molten lead, and yes, it occasionally sizzles and pops and goes flying towards your eyes or other body part. A hot blob at 700F / 370C can and will melt through your skin… and smells really bad while doing it. Use eye protection, don’t wear shorts, wash your hands afterwards, etc. Got that?
  • SAFETY B: Never solder on a live circuit. A grounded tip means a short circuit through your iron, and that means sparks, and smoke, and people screaming (usually you), and damaged circuits, and dogs and cats lying down together… You get the idea.
  • Solder is not glue. Make a good joint before soldering.
  • Soldering requires heat, but heat melts things and damages small parts. Use heat-sinks and just the right amount of heat. Practice helps here.
  • An underpowered or cheapy non regulated iron will damage parts as surely as using a too large iron. That heat thing again…
  • Cold joints are a common failure mode, as is using too much solder and causing shorts or blobs.

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