@dc42 Good to know. In that case, the 64/40 would most certainly void the warranty. Although I do have lead-free solder, about the only solder tools that I have that wouldn't be lead contaminated would be the ones that I use for plumbing.
Among other hobbies, I build audio amplifiers and sound processors. Much of that is through-hole soldering, but there's also a reasonable amount of SMD stuff in the signal processing. Still, I generally accept that when I put something at the soldering station, I'm saying goodbye to any kind of warranty.