soldering - Any issues with changing to lead-free solder?

I'm thinking of changing to lead-free solder. I've heard some people prefer a traditional Pb/Sn solder, but haven't heard any specific reasons why.

I'm mostly doing through-hole work, and I have a decent temperature-controlled iron.

So, are there any issues I might encounter with changing over? And are there any situations where I'd want to use a particular type?

Answer

Workmanship is more challening with Pb-free solder, due to degraded wetting and a higher melt point. It is often more difficult to visually verify a cold-solder joint by visual inspection, because most Pb-free solder joints 'look' cold if you judge with the same criteria that is normally used to judge conventional solder joints.

Also, Pb-free is much more prone to tin whiskers than conventional solder - in fact, way back in the day (decades ago) this was one of the reasons lead was added to solder (it's the most effective whiskering inhibitor known). Tin whisker-induced failures are more common with dense layouts and usually happen months or years after assembly.