What is this stuff?

[madsenshooter]

I'd turned my little pot on to heat up and got involved in a TV show. When I went back to check on it the temp was over 1000 degrees and overflowing with a brown granular substance that was glowing red hot! Whatever it is, won't flux back in with citric acid. It appears the thermostat was stuck on, but it wasn't much over 1000 as it quickly cooled to less. Never seen anything like it. It just looks as if someone put a handful of dirt on top of the melt, but I'm the only one here. Anyone have any idea what it might be? Looks like something that don't belong there, that much I already know.

http://castboolits.gunloads.com/imagehosting/thum_12364ea22831e3a59.jpg (http://castboolits.gunloads.com/vbimghost.php?do=displayimg&imgid=2468)

[para45lda]

Oxidation

[madsenshooter]

Shouldn't that flux back in with citric acid? Oxides of what? I guess I should ask.

[geargnasher]

I don't know what properties citric acid would have as a flux, but I'm fairly certain it has ZERO properties as a reducant.

What you have is indeed lead and other oxides, and those oxides have a very high melting point. Not that they would melt back in anyway, they need to be chemically reduced back into the melt by the addition of a sacrificial reducant such as Sawdust, and I recommend also fortifying that sawdust with additional hydrocarbons like candle wax, and when it starts to smoke light the smoke to produce extra carbon monoxide at the melt's surface. Exposure to carbon monoxide during the combustion process excites the reduction/oxidation reaction of the hydrocarbons and the lead oxide, producing carbon dioxide gas, heat, and elemental lead stripped of it's extra oxygen atoms.

For a good read, go to LASC dot US and check out Glen Fryxell's article "The 'simple' act of fluxing", he explains it better than I can. Also check out any decent encyclopedea for "Galena" and the smelting therof, you'll discover that carbon monoxide gas is used in the final smelting of lead ore to reduce lead oxide to elemental, pure lead.

Would you mind explaining how citric acid works and what it does?

Gear

[madsenshooter]

Citric acid has 3 hydrogen protons per molecule, should make a good reducer. I just put this alloy into ingots the other day. The only element I know that would oxidize so heavily at such a low temp is mercury, but there could be others. Whatever it is, it isn't going back in the pot, and I'm gong to see if I can make some more.

[madsenshooter]

Yep, I'm making more at approx 1100 degrees. Guess I've got some lead that was amalgamated with mercury somewhere along the line. Just before the little bits start glowing red, the color is more orange like mercury oxide pictured if you do a google image search. Watching the stuff form is more fun that watching crystals grow! After removal an orange film immediately forms. Then it turns blue, after that it thickens until it's about 1/16in, then the little dirt like particles start growing out of it. I've emptied the stuff twice already, the first time it was overflowing. The alloy underneath the crust looks fine.

[madsenshooter]

Well, I've got no idea what's in this alloy. I just tried casting with it and it draws away from the sides of the mold. Nothing like banana shaped bullets. I dumped it, put some lino in the pot, viola, perfect bullets. I've got nearly 30lbs of the bad alloy, guess I'll wait until I can get some high heat and see if I can burn out whatever it is. Oh well, I got it relatively cheap. Back to making good bullets....

[para45lda]

What does the alloy do at "normal" temperatures when casting?

[btroj]

Why are you heating to 1100 degrees?

The number of hydrogen protons per molecule doesn't have much to do with reducing in our situation. We need something that produces carbon monoxide. That is our reducing agent. We are not in an aqueous solution here.

Not entirely sure what you are attempting to do so I can't say if it is working or not. It is confusing most of us however.

[madsenshooter]

At normal temps, the alloy pulls away from the sides of the mold, it looks similar to trapped air, but I can see it was once against the side of the mold, pulls away as the alloy cools. Honest, I got banana shaped bullets! Also at normal temps, the slag doesn't form, oh there's the usual oxidation but not this stuff that I'm going to call a precipitate. Only reason I got up to 1100 is that the thermostat stuck. But I'm glad it did, it appears this stuff can be cooked out. Could be some low temperature metal mixed in with the WW. I've had this happen before now that I think about it. It just keeps producing this precipitate. With a half a 10lb pot of alloy, in the past I've emptied the pot 3 times of the slag. I swear it seems to defy the conservation of matter rule, after emptying the slag 3 times, I still had about the same amount of alloy in the pot! Don't worry too much about it, it's set aside for now, I just thought someone else may have encountered something like it.

[WHITETAIL]

I would take it to the scrap yard.
And then use that money to buy
lead pipe or WW in their original form.
So you know what you have.:lovebooli

[Sonnypie]

That looks EXACTLY like what I got one time when I added 60/40 rosin core solder to a pot of lead.
I didn't have the thermometer back then, and left the pot simmering at my "normal" temperature setting while I did a school run for the Grand Son. (Short run)
When I came back I had to break it to get through the crust, then dredged it all off with my pot spoon.
Shortly afterwards, I got yelled at for taking all the tin off the melt. And that I should flux the pot and stir it back in. (Without any pictures, if I recall correctly. That was when I discovered some folks here have clairvoyance.)
I figured it was the rosin core of the solder I had added for tin. The bulk of the pot was fishing weights. My first batch of lead to play with.
A long time from then to now, I stick to what alloy's I believe I can trust, Rotometals Lyman #2, and my new favorite for my pistol: Magnum Shot with a tiny slirp of tin.
But my days of Spirimentin with electrical solder is past.
But that was the only time (Knock On Wood) that I got that strange stuff on a pot of lead.
Scary stuff that stuff. :holysheep

[madsenshooter]

Thanks Sonny, it's good to know someone has ran into something similar. The base for the alloy was some 10lb , supposedly WW, ingots I got off ebay. Fellow said he used it as ballast in race karts, so he probably had access to a high heat source. God only knows what he might have thrown in. When I find the time I'll see if I can't cook it all out. Nothing melts out at a temp low enough to make cerrosafe or some other low temp alloy a suspect. Whatever it is doesn't flux back in, no matter what I use. I'll cook out the precipitate, then if it still makes banana bullets I'll sell it as scrap.

[arjacobson]

Mine looked like that once when the kids happened to plug in the melt pot instead of something else. Caught it a day later..... I had to empty the pot and clean it very well..

[madsenshooter]

Good thought, but it's a fairly new pot, and it works ok with known alloys. It's got lino in it now at 725 and all I get is the usual thin oxide layer. There's something, I don't know what, in the alloy that burns out at over 1000 degrees. The dirt like stuff feels and crunches up like little cinders from a coal furnace. Different color, but the texture is the same.

[caseyboy]

I saw that stuff once when I set the Lee 10 pound pot on setting nine and didn't drop the temp when the alloy melted. Let's just say that the alloy was slightly glowing if you blocked the light over the pot. The boolits cast were frosty and well filled out. I find now that the Lee pot setting is 5 to 5.5 with the alloy I use and all casts beautifully and I haven't seen that stuff since.

[madsenshooter]

Another good thought, but I've tried shooting the banana bullets a few times, they're ok if you only wish to make something go bang. Another odd thing with the alloy, I can cast good bullets in an iron mold at higher than normal temps, say 850, but get the bananas with brass or aluminum molds. Not every one is a banana, maybe 50% or higher though. A real pain to sort out as some of the areas where it backs away from the mold are barely visible. Oh, I've got a pic of one of them somewhere. This one is from a brass mold that casts beautifully with lino. Pic doesn't show it very well, but that supposed to be a straight taper from the second band forward.

http://castboolits.gunloads.com/imagehosting/thum_12364ea4a6b0b32e1.jpg (http://castboolits.gunloads.com/vbimghost.php?do=displayimg&imgid=2493)

[autopilotmp]

I've had some stuff that look just like that in my pot. It only happened when my pot was almost empty. When I added more lead to my pot I scraped the pot and took it off, but figured that was a mistake so I scooped it back into the pot and fluxed w/ a little wax and sawdust. Viola it disappeared and I just had some black powder that I scooped off and put in my dross pile. It has happened twice and I fluxed it back in both times w/ no ill effects. I also had my lee pot set on 7 and my boolits always come out frosty. The last few times I had it down to 6 and haven't noticed that stuff form again. Think I'll put it on 5-5.5 next time maybe the boolits won't frost. I am still learning obviously.

[Sonnypie]

I put a little wax in my pot once. It smoked like crazy (no surprise there), and it burst into flame. Not a big deal for me, but I did not expect a campfire in my shop. That pot had to be a bit hotter than I thought to self ignite the wax. :smile:
It very quickly burned out, but I think I'll stick to my Lizard Litter (ground English Walnut shells). So far it has worked very well.

I just checked and spontaneous ignition of paraffin is 473F.
Some have said to lite it off and let it burn out.

PS: Madsonshooter, I don't trust Ebray for nothing.

[madsenshooter]

Even when you know it's going to happen, the poof, as it bursts into flames scares you some and I often jerk away. 473 eh, I've read some posts here wherein fellows said you were at the right casting temp when it would ignite. Little low I'd think. There was one post on here where a fellow lost some hair when the poof occurred. Reminded me of the time I took a match to try to see what was in a bleach bottle. It had gasoline in it, I lost some hair and eyebrows on that one! The poof was more of a whoosh. I was beside a creek and the then burning bottle found its way into the stream. I should note, I was just a kid then. It took awhile for those eyebrows and lashes to grow back.

[Sonnypie]

Yup, 473F (http://wiki.answers.com/Q/What_is_the_ignition_temperature_of_pariffin_wax) ;)

[madsenshooter]

I meant the other guy's idea of casting temp was low, not your 473, figured you'd looked it up. I looked up tin oxide too, it doesn't look like the stuff I have.

[Defcon-One]

Looks like we have a lead plague! Same Stuff?

http://castboolits.gunloads.com/showthread.php?t=131520

Sounds like overheating of an unattended pot in both cases. Clean it up, watch the temperature and never leave the pot unattended for so long!

[madsenshooter]

Looks a bit like mine, mine is more crumbly, but was at a higher temp. Also my alloy won't cast, except in iron molds at high temp. Even then there might be some that pull away from the mold as they cool, just not enough for me to see. The guys on the other thread are chiding the OP about leaving the pot on. I leave mine on for days sometimes, and with lino, all I get is a thin coat that fluxes right back in. I'll cook whatever it is out when the outside temp goes down some, that way I'll save on using the furnace, aka the fire god!

[45bpcr]

Funny huh?

Two threads about the same stuff!

Seriously, I've never seen it before and have been casting for a long time :-)

45Bpcr

[madsenshooter]

In looking at my ingots, I can see some black streaks through some of them, though I know I fluxed it well. In fact, I've melted the whole batch down thrice, the last time to add tin which didn't help either. I don't know what the black stuff is, I don't get any rubber burning smell when they're melted down. You've never seen it before, some guys got all the luck! I unknowingly shot those banana bullets in a CBA match, often didn't hit the target at 200yds, and I don't mean missed the bull, I missed the whole paper! But the good bullets went right to point of aim. I went from bottom pour to ladle pressure casting, and still get the bananas. I bet if I could orient each one the same way I could shoot around corners!