First time using new lee pro 4-20 yellow/brown gross

[bassin57]

Hi,
I dont know it the SOWW lead ingots I made had zinc in them. Or that this was the burning off of the protective oil in the first use, but during my first melt I had a yellow dross that later turned brown floating on top of my melt. The first melt started as near pure lead from stick on wheel weights that I fluxed with pine sawdust and wax prior to making my ingots. In this I added tin from a bar from National Metal to produce about a 1-25 mix for the bullets I need for my 45-70 TD that was keyholing with a commercial cast bullet that had a BH of 18. With about an inch left of this melt I added COWW with a little tin and I fluxed again with candle wax and I casted 150 bullets in 45acp. I finished the melt with straight wheel weight ingots I made making some 9mm boolits. During this whole process I skimmed off enough floating dross to fill a coffee cup. I am wondering if I cleaned the lead wheel weights enough before making my ingots? The bullets appear to be OK . The 405 grn HB bullet had a average weight of 389-392 grns and a .4585 diam.I took some cutting pliers and I was able to cut them in half , so I think their softness is near that of pure lead. My two 45 acp molds produced bullets of good the 200 grn mold prod 202-205 grn bullets and the 230 grn mold produced 232-235 bullets .451.5-453 diameter. I plan on shooting these as cast after tumble lubing them. Should I remelt the ingots I had and clean them again? Or did the tin bar from National Lead contain something besides tin? I would appreciate knowing if anyone has had this happen to them.
Thanks again Bassin 57.

[Boolseye]

Zinc takes high heat to melt. Any Zinc WW will float at the top of your melt in plenty of time for you to get rid of them. If they're alloying into your melt, you're running your smelt pretty long and hot. I can't tell if you're smelting in your Lee pot, but if you are, I suggest that you get a separate smelting set-up.

You shouldn't really have to clean anything. All the **** in among your WW, plumbers lead, range scrap or whatever will come to the top as you smelt. Just skim it off before making your ingots. The only dross that forms in my casting pot is the sawdust I use to flux (even though it's already fluxed from smelting). Best of luck, I hope this helps.

[bruce381]

oxidized tin are you running too hot?

[Cowboy_Dan]

I wonder if it may be iron oxide from the clips. Did it appear when you were just running soww? Last time I was smelting coww (actually resmelting), as I was removing the clips, they shed a lot of powdered rust. It was near impossible to remove it all, and if any remains, I plan to remove it when I mix them into a casting alloy.

[44man]

I sorted all the SO's out and found most were zinc. To assume they are pure lead is the mistake.
I garbage the things now, not worth the trouble.
Keep the smelting lead at 600* and skim all the crud from the surface BEFORE fluxing.
Antimony will alloy in at 600* too if fluxed. I add pure antimony to make an alloy and never exceed 600. Zinc will float until you flux. Don't believe all the high heat stuff! Antimony will not separate at 600* if there is any tin present.

[Boolseye]

Antimony will not separate at 600* if there is any tin present.
Do you mean there has to be no tin for the antimony to alloy, or vice-versa?

[WALLNUTT]

Once antimony and/or tin is in solution with lead can either be seperated?

[Iowa Fox]

I'm not sure what you have but I can tell you this- Last fall I had a 5 gal bucket full of sorted stick on and only stick on. I kept the smelt at 650 but whatever that sticky tape was gave me the biggest snot ball I have ever seen. That 5gal bucket gave me about a gal can of black puffy crust. The stuff left a residue on my clip skimmer and laddle. The alloy fluxed up nice and the ingots look good. I don't know what else would give you the volume of residue you skimmed off other than the adhesive tape. I don't know what kind of chemicals would be in that adhesive.

[303Guy]

That yellow/brown stuff is lead oxide. You don't want to breath that dust in. It will shoot your blood lead sky high. Ask me how I know!

If you poke a dry stick into the molten lead you may see a change in color of the yellow/brown dross. It turns reddish for a while. That's the oxide changing form in a reducing atmosphere. It turns yellow again when exposed to oxygen. At least, that's what I observed.

[44man]

Antimony needs tin with it to stay in alloy, small amount is enough. But so does zinc need the glue of tin so if there is zinc present, don't flux it in. 600* is the key to remove most. The good thing about zinc is it tends to float. Looks like oatmeal. If you cast you can get galvanized boolits.
I use an antimony rich alloy sometimes and only get the normal skin on the surface with some black flakes.
To break the bond between lead, tin and antimony is beyond anything we can do.

[44man]

SO's are the worst thing to fool with. I did find a few that were pure, little things in break away strips but those painted ones can be anything. I melted a pot of them once and the whole pot was oatmeal, nothing I could do with it so it was trashed.
I kept reading about guys saving dross to recover metal so I tried that too, got about 1/2 teaspoon of metal from half a coffee can of crud. Not worth the propane.
If you think you are getting pure lead from SO's, you will just have a mess, toss the things. 10# of SO's might have an ounce of pure.