One ounce will last quite a long time. It is easy to make, there for I usually only keep a tiny bottle of 1/4 ounce on hand. If done right it ready to use in in less than 5 minutes.
After looking it out a bit, seems lead can disolve too.... but in minute proportion, so tin/lead solder and Hcl might leach some lead in the resulting stanous chloride result solution... But seems to work fine anyway
