I use Senju M705 alloy solder, it flows fine at reasonable temperatures and their newer flux formulations are less toxic. The development work on lead-free sol

I use Senju M705 alloy solder, it flows fine at reasonable temperatures and their newer flux formulations are less toxic. The development work on lead-free solder continues apace, so there have been a wider and wider array of low temperature lead free alloys on the market in recent years. This differs from the lead solder world a little in that there has only been three or four formulations out there since the 1950s. Personally, I think a lot of the avoidance of lead free solder by hobbiests is based on unfamiliarity with it. Once you have spent significant time working with it you get used to it and can work with it well.