I read frequently of casters emptying their casting pot when finished casting for the day . I leave my unused lead in the pot from one session to the next. Why do some empty the pot when done with a day of casting?

I only have one pot, I always empty it, I might want to cast a different alloy the next time...

Never have. Whatever is left in the pot at the end of the casting session….is left in the pot! 😉 memtb

I try to leave about 3/4 of an inch in the bottom.

It seems to help the pot get up to temp somewhat faster than empty and what is leftover don't make no difference to the next pot.

But i don't use stuff from Roto metals or the like i make it as i go with the stock that i have.

Unless I want to clean up the pot or spout an inch or less is always left. As already said, the residual seems to melt quicker for the addition of fresh metal.

I leave some in it. Once it cools, takes a marker and identify the contents on the top of the cooled metal.

I drain my pots quite often because of the different alloys I mess with, but that's the only reason why I do. It does provide opportunity to scrub/scrape away the schmeck that accumulates on the sides and bottom, the severity of which is determined by how clean the stuff is that goes in in the first place.

I hardly ever empty mine.

I've only empty the bottom pore to scrape down the sides and spout assembly.

I empty mine.

I always stop a couple ingots short of emptying the pot doing ladle pour. I never know what I'm going to cast next session so I pour what's left back into the ingot mold, stamp the alloy when it's cooled, and don't have a single thought about it until next time. Just seems more practical that way with multiple alloys.

I always cast out what's left into an ingot mold, turn off the pot and invert it to get the last dregs out. My casting is rather binary. I'm either casting soft lead for the muzzleloaders or hard alloys for pistols and PC carbines, and it has come to be in one or two sessions of each a year, and it is seldom I cast the same twice in a row.

I mostly use range scrap but only drain the pot if I'm going to cast pure lead for the muzzleloaders. Maybe once every few years.

I find it eay to leave the pot full. When cool write the contents on the lead with a marker.

I've only recently taken to using two bottom pour furnaces and strive to keep the same alloys going in both of them. Not always, but mostly. I use a hand ladle and cast iron pot for short runs of different alloys, match grade bullets for in my target rifles, experiments, testing, and general fooling around. (And sometimes to make a pot of soup to eat while casting a couple thousand out of one of the bottom pour furnaces. )

I always leave a little in the bottom of the pot. I pretty much use the same alloy mix all the time and even if I change up the alloy somewhat there isn't enough to make any big difference in the final BHN of the alloy. About the only time I really empty the pot is to just give it a good cleaning.