I found propane tank at the scrap yard. I used a cut off wheel to halve tank, but you may be able to use a Sawzall. I flushed the tank out with water before cutting.
Over the years I have collected lead and cast bullets with forgotten alloys. There comes a time when you must put it all in the same melting pot to prevent confusion.
Walmart sells a thick one piece aluminum muffin pan that works great for ingots. Do not use the type that has the crimped on cups...these will fall apart easily after first pour. Use a soaking wet towel underneath pan to cool ingots faster. Remove glasses when pouring to prevent fogging up. Believe me... your glasses will fog so badly (steam) you will be pouring blind.