I use the gemini mold from tackle tactics, makes 3 – 9oz sinkers, have a heap of old lead from flashing etc so with parts works out at about $1.80 ea. Have not bought a made up sinker for 6 years. I also have a jig mold, a puka bomb mold (8-160z)& a ball and pyramid mold. you can use a spoon and sand tray to make spoon sinkers too.
Get yourself a decent mask to use when making them lead is deadly stuff!
as for the water I remember trying to make some outside when it started raining….Not fun!!