Scrounging Electronic Components
Especially if you need a power transistor, MOSFET, voltage regulator, big capacitor, or reed relay which is not available locally. It just does not pay to mail order small numbers of parts, so having a grab bag assortment at home is handy.
But I have noticed that the some higher-quality PCBs just loaded with cool parts can be hard to scrounge from:
1. They are double-sided, or even multi-layered, with copper plating right through the holes (vias) so it is like pulling teeth, only harder.
2. They use no-lead (RoHS) solder which needs high temperatures to melt
3. They use surface-mount components and good luck removing and using those.
I use 15 watt, 40 watt, soldering irons, solder sucker, solder braid, flux, and a soldering gun. And for some items, a small windproof butane "jet engine" lighter as a mini torch to remove multi-pin items. Just heat-sink the legs and bang the hot PCB down to remove lots of solder at once. Of course I use gloves, safety goggles, ventilation, and proper recycling.
But the main issue is that it is getting harder to scrounge parts to build up a pile of useful stuff.
What resources do you use?