5 gal pail of ww

[Rickf1985]

I often see it suggested that melting WW at temperatures lower than the zinc melting point would avoid the risk of contamination. Just as often I wonder how one controls the temperature on the bottom of a big pot with 50-100 pounds of WW piled up in it.

I suppose that you could melt a very shallow pile such that you could see the WW on the bottom melting, but it seems like that would be a very long and expensive day heating, cooling, adding, repeat…

What am I missing?

I simply keep the heat turned down so it is not overheating the bottom, Plus I start stirring as soon as I get enough liquid to do so. I have never melted a zinc yet, they all float to the top with the clips. That is not to say I do not check them, I do. But we all are going to miss one or two. And I do not put the whole load in at once. I will add 20 lbs. or so each time after I scoop out the trash and flux. I will end up with a hundred lbs. in the pot eventually but not all at once.

[lsippell]

Just the other day I niped a 5 gal bucket of ww. I also stuck a thermister connected to a PID so I could watch the temperature which I kept at 650 to 700 on a gas burner. Even after nipping what I thought was every one, I still had 1 zinc float up!
I think next time, since I was able to keep the temperature under 700 I'll just go for floaters. My hand is still sore from those side cutters!

[Rickf1985]

You still need to check them, too many and they will keep you from circulating the lead and they will melt on the bottom. It is a balancing act.