I'm asking this in the context of desoldering consumer PCBs, with lead vs. lead-free solder. My concern is twofold:
- lead-free solder usually has a higher melting point, so the temperature should be set slightly higher to shorten the desoldering time and hence reduce the total heat transfer.
- since solder wets/tins the soldering tip, there's a chance you'll have a solder tip tinned with a different type of solder than the one your are processing, which might be a bad thing.
Are those concerns important enough to consider them when desoldering, and, if so, how can leaded solder be told apart from lead-free solder?
Note that answers with a fairly surefire solution are preferred over heuristics (e.g. visual identification).
Best Answer
Anything using lead-free solder would (or should) have a ROHS compliancy symbol. Otherwise why would they bother going with lead-free. It's not particularly easy to work with compared to old industry standard leaded solder.
Melting or remelting points vary depending on solder compositions, and there plenty of mixtures that are lead-free that have a lower melting point than leaded.
Practical solution, treat everything you are desoldering as if it has lead-free if its been produced in the last say 10 or 13 years, and don't use your regular soldering iron for desoldering.