I saw something online saying that you should leave it on for like 5 minutes. I probably only leave it on for 30 seconds. How long should one leave your casting machine on when pouring your metal?
If the metal is going to get where it is supposed to get, it will be there in fractions of a second so 30 seconds is fine, 5 minutes in way overkill and just degrading the silicon mat unnecessarily.
I think 30 seconds is fine too. It’s about how long it takes to shut off the torch and put that down. I do leave it sit still for a few minutes (depending on how big the casting is) so the metal can solidify in the mold. Then I transfer it to a brick and put a piece of brick on top while it cools to quenching temperature for the break-out.