A few days ago I was using my Tap and Die set, While making a simple threaded hole I used too much force on the handle and the aluminum part snapped broken. I decided to duplicate the part that broke using sand casting method. First I glued the two broken parts with super glue and after that it was easier to make the sand mould. It took me twice to make this tiny mould, to my opinion it's easier to create a mould of a bigger size object rather then working on a macro level making a small part. I also made a divider in a bigger flask to save time on ramming the petrobond. The casting result was very good just needed a bit of cleaning with metal file.
To create the holes and threaded holes on both sides I used my bench drill.