No, according to the metals industry the components of a lead alloy cannot gravity separate. Not in large industrial vessels and not in your pot.
Rick
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I agree completely!! A few years a ago I became interested in reloading. Before I bought my first press I already knew the basics and what I wanted for equipment by researching on sights just like this. I didn't have to post much because the answers were right there now I'm here most of you don't know me but thanks to you I'm casting beautiful boolits for my 45 and eventually for some of my other firearms. Thank you all a thousand times!!!!
DAGNABIT!!!!!!!
This quote from Rick should be in a HUGE banner headline, splashed across the top of EVERY PAGE on this site!
"THE COMPONENTS OF A LEAD ALLOY CANNOT GRAVITY-SEPARATE"!
This "gravity-separation" is a MYTH, repeat: a MYTH..... it just doesn't happen.
An alloy is not a "mixture", it's a chemical /atomic creation in which the component elements are bonded together at the molecular level.
No argument at all with Olaf's text. His observations are completely consistent with my own. I have never seen alloy constituents phase-separate for any reason, and didn't think it likely.
Funny that Bruce comes along now in this context......I had questions at the start of my work using Bruce's soft-point casting method, wondering if the "point metal" and drive band section--composed of differing metals--would simply blend during the the "fusing" phase. This has not occurred for me--some combination of gentle handling and differential specific gravities of the point portion (unalloyed lead) and tri-metal alloy (usually 92/6/2) allows the process to work. Note that I ALWAYS have the point portion of the cavity lower than the drive band section, which is natural for most cavities we use in this hobby.
From what wikipedia says white lead oxide melts at 290 C which is 522 F. Above this point lead oxides go through various reactions with themselves and oxygen. The thing to note is they are liquids and float on the lead and because there is not much of the oxides, they spread out in thin layers which can solidify when the lead cools.
As far as alloys never separating by gravity, l don't know. This seems maybe likely if the alloy is a homogenous solution at constant temperature. I have seen fractional rechystalation-dechrystalation used to separate out components of a solid solution. When two phases of a mixture are in contact they often have different percentages of components. It's gonna take alot to convince of that molten metal mixtures are homogenous and cannot settle out.
If that's the case then you should contact the metals industry. No doubt they will be shocked to learn that they have it all wrong.
Rick
I guess I ought to point out that lead oxides DO NOT alloy with lead and that all mixtures of liquid metals ARE NOT alloys. If you wish to define an alloy as a mix of metals that will not separate by gravity when liquid then I agree they won't seperate by gravity. Even non metalic elements can alloy with metals ie: carbon and iron to make steel. All metals do not dissolve in others, think of those wwclips we scoop out of our pots.
And this is why my post count is so low,I spend hours and hours reading on this forum soaking in all the experience of the veteran casters here I usually don't ask unless I just plain can't find the info I'm looking for. Thank you all soo very much!!
I'm normally just a progressive reloader/caster/shooter, but I do experiment with hunting and defensive loads for handguns. I've decided that the 223, with the right ammo, does anything that I need a centerfire longarm for. Pistol ammo, however, is very lacking in improvement, almost no progress having been made in 30 years, and the results are way, way less than what should be the case by now. We know that rifle "type" velocities do wondrous things, even with very lw bullets. So it should be obvious that such bullets and such velocities are the way to go for rapidfire controllable loads in ccw pistols. The Big heavy approach has accomplished very little, other than in huge, heavy revolvers that nobody bothers to ccw (other than under a parka, in Alaska). :-) We've had Mach II handgun loads around for decades, and even the .45 Champion of them all, Jeff Cooper, said that a .22 spritzer, 40 grs at 2200 fps, had adequate stopping power, by means of hydrostatic shock, even after piercing soft body armor.
In the laboratory you subject solutions to Jupiter's gravity by placing them in a centrifuge.
smokeywolf
Recluse,
Thanks,that was a good read.I am very much a new caster myself and you brought up some good points as well.I admit,I jumped right on in and started asking a lot of questions before reading the stickies.It was a good thing though because I enjoyed the thoughtfulness and the kindness of the people answering my questions.I made some pretty nice friends along the way too and that came from asking questions that like you say,the answers to,are in the stickies.That ment more to me then just reading through thousands of words.The knowledge on this forum is so outstanding,it's amazing and exciting to learn this new hobby of mine.My thanks to you Recluse and all who share this great world of casting and making boolits.
I am confused as to how you guys think gravity separation is a myth? So you are telling me that when I melt lead alloy the heaviest element (lead) doesn't sit on bottom while the lighter elements (Tin and Antimony) don't float to the top and create a scum that can be pulled off of the lead? If gravity separation is a myth then why would fluxing cause steel WW clips to rise to the surface of the lead? Likewise dirt, copper, bronze, etc? For that matter if gravity separation is a myth then how does a centrifuge work? Heck how does panning for gold work?
The simple truth is that gravity separation is a reality. Heavier elements sink, while lighter elements float. It's part of basic science and the periodic table of elements. Once the bond of ANY two or more elements is broken via heat or other method then gravity pulls the heaviest elements to the bottom, the next heaviest to the middle, and so on and so forth...... Heck I graduated from public school and I know that.
GoodOlBoy
Panning for gold? The gold and rock/dirt etc are not melted together. It is a myth, cannot gravity separate, what your talking about with scum on top of the melt is oxidation, a completely different thing than gravity separation. Because of the density of lead yes the steel clips will float to the top BUT the steel is not melted and part of the lead alloy.
If you believe that your lead ALLOY will/can gravity separate get ahold of the metals industry, I'm sure they will be fascinated to learn that they have it all wrong. :mrgreen:
Rick
Ok, so ethanol and water have different densities. Why doesn't booze gravity separate?
An alloy, like we are using, is similar to a solution. I can take salt, heavier than water, and dissolve it in water. If no evaporation occurs the salt will never gravity separate out. Wheel weight clips are not dissolved in the lead, they merely float in the lead.
The tin and antimony are like the salt, they are dissolved in the lead.
Go to the city pool. The chemical used to treat the water don't gravity separate out as they are dissolved in the water, as are the various minerals that cause hardness. They kids and pool floats always rise to the surface as they are suspended in the water, or dissolved in the water. The kids and floats are your clips, dirt, and grunge. The chemicals and hardness causing minerals are the tin and antimony.
The tin and antimony scum you see are because they have a far higher affinity for oxygen than lead at the melt point of our alloy. That means they oxidize far faster so the scum tends to have a higher percentage of those elements. We now have a suspension, not a solution as those oxides are far less soluble in molten lead. What fluxing does, of done with a good reducing agent, is reduce those oxides back to metallic tin and antimony which then dissolve back into the lead.
You might want to go back and revisit your high school, they might need to run a refresher course. Then again, this is just what my BS in Chemistry is telling me so I could be wrong......
Wait wait wait. Now I am not saying that lead just sitting in an ingot will gravity separate. But when heated to bond separation lighter elements float. Just as oil, water, and vinegar will make a nice salad dressing when shaken up and kept cool. If you heat it and let it sit you get separation. Likewise Lead and Zinc will separate as well, though gravity is only a PART of the equation for the separation.
From "The Metallurgy of Argentiferous Lead, A Practical Treatise on the Smelting of Silver-lead Ores and the Refining of Lead Bullion Including Reports on Various Smelting Establishments ... in Europe and America" – Manuel Eissler circa 1891.
P 287-288
“The charge is now stirred, and the zinc alloy skimmed off in the usual way. As this operation is repeated three times, it is necessary to have two desilverising pots, in order that a continuous working of the apparatus may go on. Upon mixing the lead and zinc two distinct alloys are formed—silver-zinc alloy and lead-zinc alloy. These are separated, not so much in consequence of their different specific gravity, as by the difference of their melting points. The silver-zinc alloy solidifies first in the process of cooling, and afterwards as the temperature falls the lead-zinc alloy crystallises out. “ The formation of the first alloy may be promoted by expos ing a larger surface for cooling, either by gentle stirring by hand or by a current of steam ; in the latter case the silver-zinc crystals are readily detached from the sides of the pot, and brought to the surface in the form of a pasty scum. As the formation of a rich silver alloy and a poor lead alloy require opposite conditions, the former being promoted by a minimum of zinc, the latter by an excess, the following operations can be divided accordingly into the production of a rich zinc-silver alloy and a poor zinc-lead alloy. “ The rich zinc-silver alloy is formed by making use of the alloy produced by the third addition of zinc to the former charge to the new charge of lead, and is effected by placing it at the mouth of the pipe through which the hot lead, free from antimony, is flowing into the pot. The thorough mixing is accomplished by steam, and the first zinc alloy taken off is now rich enough to be set aside. An experiment of this operation, when the lead contained 0'16 per cent. of silver after the first hour’s skimming, proved its reduction to 0'03 in five hours, whilst the zinc alloy contained from 0'74 to 0'94 per cent. “ The formation of the poor zinc-lead alloy is accomplished in a similar manner by the addition of fresh zinc only at the third operation."
So we know from this blurb that gravity doesn't have a much of an effect as melting point. "not so much in consequence" IE he didn't say gravity was of NO consequence.
If this same experiment is done in a micro G environment (Planetary Resources and Deep Space Industries are both experimenting with this as a solution for deep space mining) the crystals form, but don't float to the top. Why not? What is different? Gravity. Without Gravity the crystals don't migrate from inside the molten liquid to the top, or in micro g outside if you will. Instead they stay suspended, but crystallized within the molten mass. Only by adding a specific gravity or kinetic force (no I don't know what force is needed, I'm not THAT well read on the topic) will the crystallized particles make their way to the outside/top/etc of the molten liquid. As I understand it a good binder helps as well with keeping the crystallized state stable until separation can occur.
By the way. On the public school topic. I graduated with an advanced degree, with honors, and as a member of the All-American Academic Society, and at the time had the highest ASVAB score on record in the State of Texas. My record was beaten two years later by myself as I tried a second time to enter the military and they didn't believe my first score. Later that year a 17 year old from San Angelo beat my second score and as far as I know her score still stands as the record til this day. I have a college degree as well, and have been published as a writer. I have half a dozen different dive licenses. Was a Senior Tech Specialist III for the State of Texas for 15+ years. I have written software, designed hardware, and specialized in cross platform compatibility between antiquated systems and modern systems. I also Worked in Law enforcement for multiple years.. Have blacksmithed, gunsmithed, tanned hides, built electronics, done construction, been a licensed electrician, and am a pretty good cook. But I admit I suck at sewing on a button, which is one of the reason I married a seamstress. I have worked in my life as a cook, a stocker, a field hand, a ranch hand, a diver, a pressure vessel destructive test technician, and a few other odds and ends when I was bored.
Just because we are bright doesn't mean we are right, and the ability to regurgitate hand fed data back to a professor and thus gain a piece of paper does not make one the sole source of any given topic.
Edited to ADD: By the way if booze and water don't separate how do you make Apple Jack on a cold night in the northern US?
Thanks, and God Bless.
GoodOlBoy
These are separated, not so much in consequence of their different specific gravity, as by the difference of their melting points.
If your alloy is separating due to melting point issues then turn up the heat! Any bullet caster worth his salt knows that.
Look at the copper alloy threads. Copper added to lead alloys can cause issues with spout freezing unless the heat is turned up.
Edited to ADD: By the way if booze and water don't separate how do you make Apple Jack on a cold night in the northern US?
By allowing the hard cider to freeze partially. Water freezes at a higher temp than an alcohol solution so the first ice to form is largely water. This means removing the first bits of ice removes mostly water giving a higher alcohol content.
This is NOT gravity separation of a solution, it is removing something from the mix be freezing. Totally different.
Gravity separation of a molten, fully liquid, lead alloy at temps we use does not happen.
Well GoodOlBoy if you wish to believe that a lead alloy will gravity separate by all means please do. For all of your different jobs I didn't see mention of manufacturing magic wands, you should look into that career as one of those devices will be needed for you get a lead alloy to gravity separate. :roll:
Rick