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johnsonian09
03-06-2021, 02:13 PM
Right now I'm processing 700lb of salvaged lead. My set up is a simple turkey fried with a large cast iron pot.

After fluxing with parafin candles I pull out the black/brown dross. Been doing okay I think.

Around 70lbs in I'm getting this light green powder on the sides of my pot. Most noticable after pouring into the ingot with the pot half full.

Anyone know what this stuff is?https://uploads.tapatalk-cdn.com/20210306/a3c4574d5d5718836cca07684f8e3e42.jpg

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JonB_in_Glencoe
03-06-2021, 02:23 PM
It's some type of oxide. The surface should be silvery shiny smooth. Flux with Saw dust.

Winger Ed.
03-06-2021, 02:39 PM
I've had all sorts of mysterious crud float up, but not anything green.

I'd just keep fluxing & stirring, skim off whatever floats up, and move on to pouring ingots.

MrWolf
03-06-2021, 02:48 PM
You can use pine pet bedding from Walmart. Lasts forever if you don't have saw dust.
Ron

mattw
03-06-2021, 02:58 PM
I had green stuff one time, I was melting large amounts of lead pipe and traps. They came from an old lab building and I suspect it may have been a byproduct of copper or chromate based residue. I processed the entire batch with air filtration and outside, really smelled bad. The traps were the issue, bear in mind some of the traps were 4+ inches.

johnsonian09
03-06-2021, 04:11 PM
I was thinking it might be arsenic/copper chromate due to it's about the same color as old pressure treated wood. But still not sure.

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Conditor22
03-06-2021, 04:41 PM
I always flux with both pine sawdust and wax, it gets more stuff out than either one alone.

alternate between the 2 until you get a clean silvery surface.

bangerjim
03-06-2021, 04:45 PM
Like said----just some old oxides of something. I get all kinds of garbage on the surface when re-melting. Content and temp have a lot to do with it. Nothing to worry about.....just stand UPWIND!!!!!!!! And do not breathe the smoke and fumes.

ALWAYS flux with sawdust, not wax, when re-melting bulk dirty Pb.

Wood is a flux, which is what you want in your re-melting pot for all that dirty Pb!

Wax is a reducer (for Sn and Sb) and is used on the LAST remelt (+ sawdust) of the 3X...and always used in you casting pot to get the Sn back in. NOT Sawdust. It leaves too much burned carbon behind that settles to the bottom. Or top. And can get in your cast boolits.

dale2242
03-07-2021, 08:31 AM
Through the years one of my problems that caused culls was inclusions of dross when I fluxed only with wax.
I now flux with wax and pine shaving used for bedding.
I light the flux to eliminate the smoke.
My inclusion problem has been eliminated with very few exceptions.

labop
03-07-2021, 09:59 AM
I wouldn't be concerned. Flux and skim it off. I like to get a hardness both of an air cooled ingot and a water quenched one from a scrap batch. This will tell you where you are with alloy and grain refiners like arsenic.
labop

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Rcmaveric
03-07-2021, 10:35 AM
I have gotten green crud with sulfur and copper.

Just hit it with would shavings and let it coock..

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kevin c
03-07-2021, 01:28 PM
Scrape down the sides and bottom of your pot as you flux. I found that some dross, even though lighter than lead, will adhere to the sides and won't float up until mechanically released. It can accumulate from melt to melt, accounting for why it's showing up for you now rather than at the outset. I wonder also if lead residue on the pot interior could oxidize between uses.

Huskerguy
03-07-2021, 03:56 PM
Scrape down the sides and bottom of your pot as you flux. I found that some dross, even though lighter than lead, will adhere to the sides and won't float up until mechanically released. It can accumulate from melt to melt, accounting for why it's showing up for you now rather than at the outset. I wonder also if lead residue on the pot interior could oxidize between uses.

This. It sounds like what you see seeing is a normal separation of metals. I agree with just scrapping the sides and bottoms and getting it to remix.

I was reading "the book" on casting bullets and was surprised to read they recommended hard woods for flux. The common recommendation I see is pine. I typically use pine and candles but have bees wax I am wanting to try.

Note that while pouring bullets, I find I have to keep the mix together by occasionally slowing down and stirring.