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).