I have a question regarding electromagnetic fields generated by mains-powered irons. Is it best to switch off/unplug the iron, once heated, prior to soldering *any* semiconductor (transistor, chip)? Up til recently, I had only considered the heat threat by heat sinking the component.

For this reason, and others, I may go for a cordless iron soon. Does anyone have pros/cons for going cordless?

Thanks for any input!
Clyde

Hello.

Have not heard of any troubles with soldering components in PAiA kits with a mains powered iron, but have heard reports of the heat from portable irons damaging the printed circuit on boards.

With the 60/40 tin/lead resin core solder recommended for soldering PAiA kits, you shouldn't even have to be concerned with heat-sinking when soldering the parts to the board.

Thanks!

Thanks. That makes me feel better about how I did the soldering so far, as well.
In addition to my Paia kits, I'm currently fixing a Fender solid state bass amp, and it looks like I will need to desolder several transistors to test each, due to a distortion problem in the push/pull part of the circuit, and this will help quite a bit.

On the Fender amp, it could have a board built on an assembly line and with wave soldering with the lead-free type of solder, and possibly the plated-holes of a double-sided board. It needs more heat and doesn't readily flow the second time around. Desolder what you can first, then flow in some tin/lead, desolder, and maybe again another time or two, displacing the lead-free with the better wetting tin/lead rosin core.

Or, if you can get the tip of the iron on all three legs and pull the transistor out while the solder is melted, you can do the above to clear the holes for the re-install.

The lead-free solder can eat the iron tip, so wipe it good on a copper scouring sponge to get this stuff off the tip. Coat the tip with some tin/lead and wipe it on a damp sponge.

This PT topic deals with ICs on double-sided boards with plated-through holes:

https://www.paia.com/talk/viewtopic.php?f=29&t=48

Thanks Scott,
I appreciate your help!