Rebonjour RedG, bon pour connaissance une autre aficionado française..J'habite au 6eme pres les St Germaine.
1/ Our use of the RoHS was as a transformer manufacturere and required 100% LF solder, pots, leads, components. A single leaded part of the chaine makes the procee leaded and contaminats the equipment eg the solder pot.
2/ The main issues we found were higher solder temp, thus all parts must withstand higher temp anf longer time, the reflow temp profiles are more critical.
The plastic temp range of any solder (transaition solid><liquid) depends on the mix, eg Sn/Pb 63/37 Eutectic has no plastic range and lowest T liq.
Finally there are reliability issues re plating of leads and tin whiskers, but these do not impact hand soldering hobby use.
3/ The LF solders include tin, Ge, Silver etc. and all of these heavy metals are not risk free to the environment.
4/ The Eu has REACH, RoHS, WEEE and many toher regs that apply even to LF solder.
5/ The use of Tin was restriced in USA by an old law that required proof that the tin is not from an African mine with conflict minerals.
Finally saw your other notes re soldering irons, we use Metcal SP-200 500kHz for large area, gr plane etc and found these far superior to the Hakko or any Chinese clones.
Full disclosure...my design for Raychem/Metcal ~ 1991
Bon Soiree,
Jon