cast iron lead pot, how clean?

[Brokennock]

A friend gave me a rusty old cast iron pot I intended to use to melt bulk lead in order to skim it and mold smaller ingots for use in my Palmer Hot Pot -2. I am in the process of trying to clean the rust using Evaporust and abrasive pads.
Just how clean do I need to get it? As long as the loose flakey rust is gone, is that good enough? Any ideas for a final clean to get the evaporust and last of the loose debris out so as not to add more contaminants to the lead?

 

[Gene L]

I cleaned out three rusty cast iron pots by filling them with charcoal and burning them out. What was left I removed with a wire brush.

They're very clean now. I cook with them.

 

[necchi]

As long as the loose flakey rust is gone, is that good enough?
,,,,so as not to add more contaminants to the lead?

That's about it. Any iron scale left will float with typical flux and stir,, and be able to be skimmed off the top.

 

[ZUG]

I've used a wire wheel of different styles (cone, flat wheel) in an electric hand drill. I get it as clean as I can with the wire wheels this way I don't have to fight the excess dross coming from the pot only from the lead :v .

 

[coloradoclyde]

I cleaned out three rusty cast iron pots by filling them with charcoal and burning them out. What was left I removed with a wire brush.

They're very clean now. I cook with them.

I throw mine upside down over a gas grill for a couple hours....or straight in the campfire...

 

[Brokennock]

Thanks all. As usual, I'm over thinking things.

 

[BrownBear]

Any iron scale left will float with typical flux and stir,, and be able to be skimmed off the top.

I give it a sorta scrape before starting, then once the lead is molten, scrape it real good, flux, and remove the float. The rust pops free nice and easy after heating, and the lead/flux does a perfect job of floating it to the surface where it's easy to remove. No contamination from the iron.

Been doing it that way 50 years, and no hassles, no regrets.

 

[Idaho Ron]

Any iron scale left will float with typical flux and stir,, and be able to be skimmed off the top.

I give it a sorta scrape before starting, then once the lead is molten, scrape it real good, flux, and remove the float. The rust pops free nice and easy after heating, and the lead/flux does a perfect job of floating it to the surface where it's easy to remove. No contamination from the iron.

Been doing it that way 50 years, and no hassles, no regrets.

That is the way I roll. Has worked for me for years.