What is this stuff.

[mr-natural]

In response to suggestion posted on a thread I started called "Boolit Analysis" I fluxed my lead 3 or 4 times using a pinch of sawdust. Put in the pinch, stir, skim and remove the contaminants, repeat. Ran temperature to about 700 per suggestions made on the above mentioned thread. Poured about 12 boolits and stood up to look into my melt, and this is what I saw:128385
I skimmed and skimmed and the stuff kept floating to the top of the melt. If you look very closely at the photo you will see that some of the grains are glowing red. The "stuff" is light. This photo shows how much "stuff" I skimmed off. This cereal bowl was empty when I started skimming. Remember I used, at most, 4 pinches of sawdust.128386 Does anyone know what's going on here? The "lead" I was using was from some years ago and the only thing I know is that I mixed a small ingot of 8.3 BHN and another small ingot of 11 BHN material. After my last flux the surface was nice and clean and shiny. Five minutes later I find all this "stuff".

[skeettx]

Iron Oxide, see if a magnet will attract it.
Probably had some stuff with rust in with it when you melted.

Or it may be Lead Oxide
http://en.wikipedia.org/wiki/Lead%28II,IV%29_oxide


Mike

[GP100man]

Looks like a sulphur based contaminate ???

The boolits ya cast ,did they have any inclusions/debris visible ??

A pinch is just what ya can pick up with 2 fingers ,rite ???

[mr-natural]

Skeettx it is non magnetic, just got back from checking.

[mr-natural]

GP100man, you are correct, a pinch is what can be picked up between my thumb and index finger. Admittedly I have large thumbs but they're not that big. The boolits did have some imperfections. I wouldn't say the boolits had inclusions but they did not have a uniform look - sort of blotchy, some worse than others, but the temperature had not stabilized in the mold before I saw the stuff forming on the surface and quit pouring.

[RickinTN]

Whatever it is your sawdust worked.
Rick

[madsenshooter]

When you get an answer, rather than just speculation, let me know. I've seen it several times, most recently yesterday. The crust forms above the oxidized tin. I broke through it and the melt was about 1/4" below. I'd left my pot on while doing something else for a couple hours and came back to find stuff that looks like it came out of a coal furnace! Paraffin and citric acid didn't effect the crust at all.

One thing I have noticed, I only run into it when I use WW. Could some of them have a lot of impurities?

[coffeeguy]

Just wondering, those ingots you used in your melt, did you cast them? What were they cast from? Do you remember anything funny with your melt then? Many years ago I tried smelting an old, rinsed-out car battery and got LOTS of similar-looking junk. Looking forward to hearing what you figure out....and at least you caught it early!

[high standard 40]

I have seen this (or very similar) before. I has been quite a while and I don't remember the exact circumstances. I have no idea what it is. I feel that as we go along, scrap lead alloys will see more and more weird stuff blended in. I will continue to use wheel weight alloy for my less critical shooting needs. But I have now switched over to foundry Hardball alloy for all my serious casting. I know some people's budget will not allow that. With scrap alloys we will just have to plunge ahead with what we have and work around the obstacles as we get to them. Again, in regards to the OP's question, I have no idea what that is but you seem to have been successful in fluxing it out of your alloy. You should get much better mold fillout now and less surface flaws.

[madsenshooter]

Happened to me again today. I have to very careful walking away from my pot because sometimes the thermostat sticks and it doesn't take long to get up to red hot! I wasn't away from it twenty minutes and went back to find it glowing red with 1/4" of this crud on the top. Just looks like dirt to me. I just hate to think that I've cast bullets with all that dirt in them! Oh, I tried sawdust, paraffin and citric acid, the dirt just laughed at me! After I took it out I had some better finished bullets than what I was getting previously. I'm swearing off of WWs!

[skeettx]

OK, try this, heat up the stuff and see if it becomes magnetic

[MaryB]

I have seen it from wheel weights, never that much. Skimmed it and went on...

[mr-natural]

WW is what the ingots were made from so there must be linkage from what everyone else is saying. Probably the only way to find out exactly what it is would be chemical analysis and I don't have access to those tools anymore.

[mr-natural]

This phoenomena may be related to temperature. For the fun of it I remelted the same ingot yesterday but kept the temperature lower, fluxed with bullet lube a couple times and cast a few boolits. No crud formed but the boolits have lots of inclusions. By the way, is it OK to fire boolits with inclusions as long as I'm not expecting great performance?

[RickinTN]

Bullet lube is not a flux but makes a very good reductant. The saw dust is a flux and was doing the job you asked of it. A flux removes impurities, which is what the stuff is you are removing, impurities. A reductant returns wanted elements such as oxidized tin and such back into the melt. The inclusions in your bullets are because the impurities are still in your mix.
Rick

[runfiverun]

when I worked in electro-ceramics the lead oxide powder we got in was always an orange color with a little yellow tint to it.
tin oxide was grey.

[mr-natural]

Thanks RickinTN, I lean something new every 10 to 15 years, now if I can just make it stick. Do you suggest using the deductant first and then fluxing or visa versa.

[tomme boy]

Is that pot new? I got some of that stuff when I had a new LEE pot. If it is the lead, I would want all of that out of it.

[Geppetto]

PM incoming, I can test it...

[mr-natural]

Runfiverun, that seems to be the best "educated" guess as to what that junk was. I have not spent much time to see what is required to make PbO but according to Wikipedia Pb02 will go to Pb3O4 at 707 degrees but it takes 1,121 degrees to go to pure PbO. I was in excess of 700 degrees when the stuff started forming so it might be Pb3O4, called minium, red lead, or triplubic tetroxide. However the pictures of minium are very red. So it might be the stuff formed before the minium which is Pb12O17 and I couldn't find a picture of what that looks like. But all this begs the question where is the Oxygen coming from other than the air, and why does it only form some of the time. PbO2 in the wheel weights would explain this - I think - but I failed Inorganic Chemistry so what do I know?

[mr-natural]

Yes tomme boy, the pot is brand new - first time I've ever used it.

[Springfield]

I never had this happen with WW but if you have ever melted down roof flashing you will find that you get LOTS of impurities that look like flakes of rusted steel or iron. Compared to melting down sheets of x-ray room lead and you will get almost no dross at all. All lead is not the same. I like to clean my lead with sawdust mixed with beeswax based bullet lube. That way i can flux and reduce at the same time. Stir it all in well and then light the smoke on fire.

[milrifle]

I got the same thing or something similar when smelting the stuff I got out of my snail bullet trap. I did not think to take pics, but I described it on here and some of the more knowledgeable ones (Don't remember which ones, now or I would credit them) said it was probably lead oxide and recommended I put a lid on the pot next time I smelted my "range scrap". I use that term loosely, as it was NOT stuff dug out of a berm. It was stuff from under the slot in my snail trap. while there had been a few factory rounds fired, the vast majority was my own cast rifle bullets, which seem to turn to dust as they hit the trap. It is my understanding that this 'dust' oxidizes rapidly and it is not really lead was trying to melt, but lead oxide. While I don't remember the exact instructions I was given, I do remember that I should use a lid next time. Rest assured I will find that thread and re-read it (And this one) before I smelt any more of my own "range scrap".

[milrifle]

Here is a link to the thread I just mentioned.

http://castboolits.gunloads.com/showthread.php?263272-Disappointed-in-my-quot-Range-Scrap-quot

[runfiverun]

moisture in the air will introduce 2 parts of oxygen to the lead.
look at lead left out in the elements and see the white stuff on it,, that's lead rust [oxides] those are what is super hard to reduce and return to the pot it's also what produces the orange/red/yellow dust.
it's also why I recommend the wax covering when working with it, the wax is like the dust stopper and allows you to stir and mash it without the dust.

lead oxide dust is also the most harmful stuff we deal with as far as contamination and ingestion which causes lead poisoning.
I would rather throw away 2 pounds of this stuff rather than get it all stirred up and floating around...

[coffeeguy]

This phoenomena may be related to temperature. For the fun of it I remelted the same ingot yesterday but kept the temperature lower, fluxed with bullet lube a couple times and cast a few boolits. No crud formed but the boolits have lots of inclusions. By the way, is it OK to fire boolits with inclusions as long as I'm not expecting great performance?

Absolutely. And considering that the boolits are rotating in flight, it's not like one is suddenly going to go off at 45 degrees from your line of sight. You could just re-melt, flux and re-cast, but like you said if there's no huge expectation of performance then just save the time and load/shoot 'em!