I have used some of the lead free solders from the hardware store with success.
Lead-free Solder
Tin-Silver: This alloy is an excellent replacement for the 63/37 tin-lead solder and is widely used in many industries, from electronics to plumbing.
Tin-Copper: It’s one of the most popular lead-free alloys, with excellent thermal and electrical conductivity. It’s ideal for electronics and other applications.
Tin-Bismuth: This is the lead-free alloy with the lowest melting point (only 95°C or 203°F). It’s ideal for working with delicate thermal sensitive parts.
Tin-Zinc: This alloy offers great ductility and has a relatively low cost. It’s great for working with aluminum and galvanized steel. It’s not the best in terms of anti-corrosion and oxidation properties, but it does the job.
Tin-Antimony: This solder creates hard connections and is widely used in industrial applications.
Tin-Nickel: This solder is widely used in the aerospace industry because of its excellent mechanical properties and resistance to thermal cycling.
Robby