A week or so ago, I posted a notice about a sale on Weller soldering stations to our club mailing list. A short discussion followed on different soldering irons.
Dave, WB4SBE replied:
I would only like to add a caution to those considering some of the more simple soldering pencils out there. I found (the hard way) that they don’t necessarily offer good isolation from the power line. For the really cheap ones, depending on which way you have the soldering pencil plug inserted in the socket, you may have the tip connected to the hot side of the AC line, or if there is some insulation there, it may be pretty flimsy thin paper stuff that will wear quickly and present a hazard.
Don’t depend on polarized (or sometimes even grounded) plug arrangements, because chances are that someone, sometime miswired the socket, and you may not be protected.
Even if the tip is grounded, beware waving it around a circuit that may suffer from the same wrong-polarity plug-ness. Make sure that any item you are soldering on is unpowered and unplugged, for safety’s sake, even if you are soldering to the supposedly ground-potential chassis.
I stick to transformer-isolated soldering stations now, since that particular soldering pencil melted in my hand in a shower of sparks that one day, many years ago…
Klaus, N8NXF also chimed in with this advice
Yes, stay away from the real cheap soldering irons. I have done most of my soldering with soldering irons that do not have grounded tips. If the circuit you are soldering on is not electrically connected to ground, which would complete the circuit, no current can flow so no damage can be done to the circuit. The danger with grounded tip irons is that if you DO happen to touch something “live” with it you will get a shower of sparks on an unprotected circuit no matter how good the soldering iron is.
These days I feel the best form of protection is the ground fault circuit interrupter or GFCI. A GFCI will disconnect AC power the instant it senses a difference of just a few milliamps between the black and white wire in the AC line powering your soldering iron and any other equipment plugged into it. It can save your life and is required by code for new construction in wet locations and basements, etc. It doesn’t even require a third ground wire to operate. A GFCI outlet can be had for under $10 from most any hardware store and can be used to protect all outlets downstream from it. They fit into a standard box making it easy for a knowledgeable person to retrofit an existing power circuit. I have built up portable outlet boxes with GFCI’s in them for use when I work on unprotected or questionably protected line powered equipment.
Great advice, if you ask me.
Betty Hunt says
Thanks for the useful information!