Safety tip: check the composition of your metal before melting it, and if there is any lead or antimony present, or even if there might be, make sure you're doing the work in a well-ventilated place and while wearing a fume mask. A dust mask is not sufficient.
Lead vapours are incredibly pervasive, and toxicity builds up quickly. It can take years for the body to excrete lead build-up in body tissues.
Trust me, you do not want even a mild case of lead poisoning, and I speak from personal experience.