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Thread: fluxing technique

  1. #81
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    Retorts? Why?
    I simply pointed out that some words have multiple meanings and that understanding the context of the usage helps one know which meaning is relevant.
    You will learn far more at the casting, loading, and shooting bench than you ever will at a computer bench.

  2. #82
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    I believe I was mistaken about what "reduction" is. I think of flux as something that returns metal into the alloy, and I have observed, and tested that happening.
    What I'm just not sure about is this bit about removing the impurities in the activated carbon.

    GG, good to see you back! And you brought Btroj!
    Alright, I'm speaking in this thread about what I have personally witnessed, observed, and tested to be true in my shop. Certain things I can stamp my feet on, and others I have nothing but someone's word (granted it's someone I respect very much) that the other part is so.

    However, you're a descerning person. If someone tells you the earth is flat, you are not the type to take their word for it. So tell me: how have you demonstrated to yourself beyond just the printed word that what you claim is true? How did you prove the concept?
    Tim Malcolm
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  3. #83
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    Oh and there is no reason for retorts. We're trying to have an enlightening discussion.
    Whoop it on me. How do I prove this?
    Tim Malcolm
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  4. #84
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    Simple. Carbon, such as produced by low order combustion, excels at aDsorption. Notice, it aDsorbs, not aBsorbs. Adsorption is the binding of agents to a physical surface. Carbon like we are talking has a huge surface area. That surface can bind to many things in our melt. A wax simply does not produce any meaningful amount of absorptive surface.

    What we want is a "flux" that does two things. We need low order combustion to produce Carbon monoxide. We also want to produce a charred substance with lots of surface area. Sawdust does both of these.

    A couple key points to remember. Rick mentioned time and close contact between impurities and the absorptive surface. For our charred material to adsorb anything it must come in close physical contact with that substance. This means lots of stirring, pouring, and mixing of the charred material and the molten alloy. I think a minute or more isn't out of the question. We also need to remember that the charring of the material produces our reducing atmosphere at the surface of the melt. This is why using activated carbon doesn't really help, it just adsorbs everything yet doesn't reduce anything as it produces no reducing atmosphere. I also don't liek the extremely fine nature of some activated charcoal on the market, the small particle size makes it far easier for those particles to remain in suspension within the melt. Why use a flux that can possibly become an impurity? Sawdust reduces this likelihood as it produces residue of a particle size that is far less likely to remain in suspension.

    I have never done an actual wet lab analysis to back up my theory on this. What I use is my strong chemistry background, 30 years of casting experience, and a reliance on my ability to observe what happens and what works. I used to use wax, since I went to wood shavings I have found my melt is cleaner and I get far more of the oxides and oatmeal like junk on the surface to mix into the melt. The stuff I skim from the surface contains far less obvious metal.

    As a side note it was pointed out earlier that many load manuals and other shooting references mention the use of wax as a flux. This is true but I will point out that while Lyman manuals mention the use of wax as a flux they also point out that linotype bullets are required for any level of accuracy above 1600 fps in micro groove rifled barrels. Just pointing out that sometimes personal experience outshines the printed word particularly if that printed word is merely a rehashing of old knowledge and misinformation.
    You will learn far more at the casting, loading, and shooting bench than you ever will at a computer bench.

  5. #85
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    Quote Originally Posted by goodsteel View Post
    Oh and there is no reason for retorts. We're trying to have an enlightening discussion.
    Whoop it on me. How do I prove this?
    Easy. Take samples from the pot using a variety of fluxes. Melts some wheel weights and don't flux. Take a sample. Flux them and take another sample. Have each sample analyzed for both exact alloy composition but also for particulate matter suspended in the melt, things like dirt and grit.

    I said easy, I didn't say it was gonna a be cheap. I bet you are looking at a couple hundred bucks for a full element analysis of each sample using ICP or AA. Particulate matter won't be cheap either.

    In short, if you want proof then you need to pony up at least $10K in my opinion. How bad do you want that proof?
    You will learn far more at the casting, loading, and shooting bench than you ever will at a computer bench.

  6. #86
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    Ok Tim, I just re-read your posts in this thread and your confusion (yes, your confused) comes from an incorrect use of the word "reduce". When you reduce oxidation to the melt your not removing anything. In metallurgy to reduce means to return to the melt, not remove it. It is still there but no longer as oxidation on the surface but in a molten metallic state.

    To clean the alloy via fluxing is to remove contaminates (things we don't want in there). To "know" something has been removed we must first know it was in there. In none of the XrF testing did I see any example of this. That means the WW samples were cleaner than any of us thought or the XrF testing is flawed in some way as Brad suggested. I suspect that it may well be a combination of the two but have no way prove either.

    Larry can argue all he wants but in metallurgy "reduce" means to return oxidation to the melt. To "flux" means to remove contaminates. To many bullet casters "fluxing" simply means to clean the alloy even if they don't understand the metallurgy of reducing. Sawdust does do both, it is a reductant and it can remove impurities (assuming they were there in the first place). Larry has accused me in this thread of re-writing and spreading myths. Larry clearly doesn't understand the metallurgy of reducing and cleaning an alloy. Larry clearly has no intention of learning it, much easier to slander me.

    Rick
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  7. #87
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    Quote Originally Posted by btroj View Post
    Simple. Carbon, such as produced by low order combustion, excels at aDsorption. Notice, it aDsorbs, not aBsorbs. Adsorption is the binding of agents to a physical surface. Carbon like we are talking has a huge surface area. That surface can bind to many things in our melt. A wax simply does not produce any meaningful amount of absorptive surface.

    What we want is a "flux" that does two things. We need low order combustion to produce Carbon monoxide. We also want to produce a charred substance with lots of surface area. Sawdust does both of these.

    A couple key points to remember. Rick mentioned time and close contact between impurities and the absorptive surface. For our charred material to adsorb anything it must come in close physical contact with that substance. This means lots of stirring, pouring, and mixing of the charred material and the molten alloy. I think a minute or more isn't out of the question. We also need to remember that the charring of the material produces our reducing atmosphere at the surface of the melt. This is why using activated carbon doesn't really help, it just adsorbs everything yet doesn't reduce anything as it produces no reducing atmosphere. I also don't liek the extremely fine nature of some activated charcoal on the market, the small particle size makes it far easier for those particles to remain in suspension within the melt. Why use a flux that can possibly become an impurity? Sawdust reduces this likelihood as it produces residue of a particle size that is far less likely to remain in suspension.

    I have never done an actual wet lab analysis to back up my theory on this. What I use is my strong chemistry background, 30 years of casting experience, and a reliance on my ability to observe what happens and what works. I used to use wax, since I went to wood shavings I have found my melt is cleaner and I get far more of the oxides and oatmeal like junk on the surface to mix into the melt. The stuff I skim from the surface contains far less obvious metal.
    [snip]
    This is what I was alluding to earlier. Since adsorption removes all metal oxides, including the ones we want to keep, we need to first reduce the good stuff, which can easily be accomplished via charring wood. Combustion is a redox reaction itself, actually. The oxides of things we want to remove are less easily reduced by the same means, and hang around to get caught in our adsorptive trap forming as the wood carbonizes. Physically expose the unwanted oxides to the trap via the sluice method and voila'! You got them. Now, if the unwanteds are already in elemental form, in the alloy solution, you're stuck with them more or less until you can coax them into oxidizing again or add things that they will bond with in elemental form. Nobody claimed this was process was perfect, but it's quite effective in what it does accomplish.

    Gear
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  8. #88
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    Imperfect as it may be it is far better than anything else we have.

    Worse thing to use is Marvelux as it just grabs all the oxides and removes them. That stuff would be awesome for removing particulates but the resulting residue it leaves is hygroscopic as all get out and it removes too much stuff we want in the melt. Maybe it would have a use in smelting range scrap after a good fluxing with sawdust to reduce the oxides and get rid of most of the grit?
    You will learn far more at the casting, loading, and shooting bench than you ever will at a computer bench.

  9. #89
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    Quote Originally Posted by geargnasher View Post
    This is what I was alluding to earlier. Since adsorption removes all metal oxides, including the ones we want to keep, Gear
    Precisely!

    A good example of this that many bullet casters are familiar with is Marvalux. It is a true flux but it is not a reductant, it removes everything it comes in contact with including our tin and antimony. Many other problems with using Marvalux such as highly hydroscopic, rusts up everything and my biggest pet peeve with it is that it so horribly gunks up everything, tools, your pot, everything. But it is a true flux.

    Rick
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  10. #90
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    Quote Originally Posted by btroj View Post
    Imperfect as it may be it is far better than anything else we have.

    Worse thing to use is Marvelux as it just grabs all the oxides and removes them. That stuff would be awesome for removing particulates but the resulting residue it leaves is hygroscopic as all get out and it removes too much stuff we want in the melt. Maybe it would have a use in smelting range scrap after a good fluxing with sawdust to reduce the oxides and get rid of most of the grit?
    Great minds think alike.

    Rick
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  11. #91
    Boolit Master
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    http://www.chemguide.co.uk/inorganic...roduction.html

    This Is how a blast furnace works to produce pig iron from iron ores.

    I don't use a dictionary to explain chemical terms that I learns while earning a BS in Chemistry. I KNOW what reduction is as it pertains to metal oxides and getting them back into the melt.
    You will learn far more at the casting, loading, and shooting bench than you ever will at a computer bench.

  12. #92
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    http://www.chem.memphis.edu/bridson/...m/T12a1100.htm

    Oh no, a specific example of a metal oxide being reduced at the bottom of the page. Oh the horrors, a university publishing such falsehoods.
    You will learn far more at the casting, loading, and shooting bench than you ever will at a computer bench.

  13. #93
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    Quote Originally Posted by montana_charlie View Post
    Removed and reduced are two different terms with no similarity in their meanings when used in our context.

    Yes, if you can 'remove' some copper from your molten alloy you have 'reduced' the amount of copper.
    But, that definition of 'reduce' isn't correct in a discussion about oxides on a potful of bullet alloy.

    Reduction of oxides describes 'removing oxygen molecules' in order to return the material to it's metallic state.
    Take a potful of pure (certified) lead and let it remain molten for 30 minutes.

    You already know that a grey scum will form on the surface.
    You can even stir it to expose more metal to the air, and the scum will get thicker ... and eventually begin to clump a little.
    This is oxidized lead. (We know it's oxidized lead because there was nothing else in the pot to start with.) If it gets inside a bullet, it will mess it up.

    When you stir sawdust or beeswax around on the surface of that scum, it smokes and (perhaps) catches fire. Fire consumes oxygen, and it pulls the oxygen molecules out of the lead oxide on the surface of the molten metal. The presence of a very carbon-rich environment prevents immediate reoxidation, so the scum disappears and the remaining ash can be removed.

    What was 'scum' (lead oxide) is now usable lead, again.
    The same amount of metal is in the pot as there was when you started, so there has been no 'removal'.
    But 'reduction' has occurred and the evidence detected by "your eyeball" (scum is gone) is sufficient proof.


    I won't go into 'removal' because I don't use any scrap which requires it. So, my knowledge in that area is quite limited.

    CM
    That is one of the clearest, easy to read definitions I have read in sometime.
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  14. #94
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    Neither Gear not Rick implied, stated, or otherwise commented on a metal reducing from the alloy as the alloy melts.

    We are speaking of metal oxides such as tin oxide that forms on the surface of raw ingots, range scrap, and the surface of the melt. We are reducing the tin oxide with which adds electrons to the tin and gives us back metallic tin. This metalloc tin is then able to be returned to the alloy.

    Tin oxide isn't going to mix with the alloy and becomes an impurity. It would be an inclusion if it got inside the mould cavity.

    We are reducing the metal oxides back to base metals so they can remix into the alloy. Nothing else.

    This is is simple science, smelters use reduction all the time to get base metal from various metal ores where the desired metal is found as an oxide.
    You will learn far more at the casting, loading, and shooting bench than you ever will at a computer bench.

  15. #95
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    Ok, you experts continue using what you want to flux or reduce your alloys all you want. I couldn't care less. I like many others will continue to use wax to flux my alloys with. I'm sure the rest of the bullet casting world that uses wax (most of that world) to flux their alloys with will also go on continuing to flux with wax........because it works very well.........

    I guess all you experts still think that grey oxide "scum" up on top is just tin?

    Larry Gibson

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    Quote Originally Posted by goodsteel View Post
    I believe I was mistaken about what "reduction" is. I think of flux as something that returns metal into the alloy, and I have observed, and tested that happening.
    What I'm just not sure about is this bit about removing the impurities in the activated carbon. Might try a Google search for "Adsorption" and have a read.

    GG, good to see you back! And you brought Btroj! There you go, jumping to conclusions again. C'mon, Tim, please try to somehow learn to stop assuming things without basis, ok? You made this same mistake in a post the other day after I told you on the phone exactly what the score was, why do you have such difficulty retaining correct information, do you think that reality for others is what you choose to make up?
    Alright, I'm speaking in this thread about what I have personally witnessed, observed, and tested to be true in my shop. Certain things I can stamp my feet on, and others I have nothing but someone's word (granted it's someone I respect very much) that the other part is so. The problem that seems to be haunting you here is you only accept two ways of learning: That which you personally witness, and what others tell you. You judge the validity of what you are told or read by your feelings. Not very scientific. So if you can't physically see it, and seem to think that that leaves you only with "nothing but someone's word", you won't know it to be true. That's not going to get you very far in understanding things like fluxing alloys. What you need to nurture, for your better understanding, is scientific understanding of phenomena you cannot see. You can't see a valence electron, and in a lot of cases can't see an ionic attraction, but smart people have developed simple ways to mathematically demonstrate exactly what and how happens in a chemical reaction. You put such-and-such amounts of x,y, and z together under certain conditions, a reaction follows, you get certain amounts of a and b and depending on the molarity, possibly leftovers of x, y, and z. It's like Algebra, and like Algebra, if properly worked gives definitive answers without needing physical experiments. The experiments that prove the math have already been done generations or centuries ago by people a lot smarter than you or me.

    However, you're a descerning person. If someone tells you the earth is flat, you are not the type to take their word for it. So tell me: how have you demonstrated to yourself beyond just the printed word that what you claim is true? I have, in fact, written the chemical equations for the reduction of several metal oxides on this site. I have written exactly what happens when you combine certain metal oxides with hydrocarbons and carbon monoxide, and what the result of that WHOLE reaction is (It's actually two half-reactions, reduction is only one half, the conversion of CO to CO2 is the oxidation half of the reaction which takes place at the same time), and what all the by-products are. Please do go look it up, I weary of repeating myself. How did you prove the concept? I proved it via a chemical equation. If you saw it and understood it, it would be obvious. You also need to research how industrial non-ferrous ore smelting is accomplished.
    Now, this is going to sound condescending but it isn't meant that way, I'm only responding you what you tell me is your only two ways of knowing the world around you. One of them is ok in some instances, like reading a mic or making observations through a bore scope, but still very limited. The other way leaves you at the mercy of believing who ever shmoozes you the most or whatever it is that makes you trust them. I'm sorry, but if I'm taking people only on word and credentials, do you think that regarding non-ferrous metallurgy, I'm going to believe what Dr. Fryxell writes or Larry Gibson? If YOU are only taking people on word or credentials, how is Dr. Fryxell not good enough for you? HOW? Because he didn't shmooze you enough? I don't get it. If I have my doubts about either, I find out how each came to their conclusions and figure it out for myself. You HAVE to expand that if you're going to get any of this. The physical world has been explained through chemistry and physics in great detail. The reason for those sciences is to measure, understand, and predict things we cannot see or touch. You add vinegar and baking soda and you get water (aq), CO2 (gas), and sodium acetate, and a little heat energy is exchanged. I don't need to react vinegar and baking soda and send the reactants to a lab to have them analyzed to know, chemically, what that white powder and clear liquid is that I have left because I can do the math on paper. Make sense?

    Oh, and I know the world is spherical because it has gravity in the downward direction (toward center) and there is a horizon perpendicular to gravity in all directions. I also know it must also be spinning due to those things as well. I didn't need pictures taken from the surface of the moon or to fly around the earth to know for sure.

    Gear
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  17. #97
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    OK, I was obviously confused about the terms.
    I'd still like to know how anybody knows for sure that there is anything more than carbon and oxidized metal in the dust we scrape off the top of the melt.
    I'm obviously very confused as well on where the burden of proof lies when a theory is stated as fact.......
    Tim Malcolm
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  18. #98
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    Obviously someone is held back by the basic chemistry knowledge threshold.

    Tim, if I asked how you know for certain something you machined was precise what would you say? Part of it would be that you KNOw what you are speaking of. This is no different.

    Some of us have specific knowledge in specific areas beyond what the average forum member knows. At some point you can either trust that knowledge or you can go down a different path.

    I choose to trust my education and experience as you trust yours as a machinist. The fact others fail to grasp the basic concepts is not my problem, it is theirs. Arguing with those who don't understand the concept being discussed borders on ridiculous. I suppose I just need to come to grips with the fact that some people are never, and have never, been wrong.

    I apologize to Don Quixote for steppng on his toes, I should know better than to tilt at windmills.
    You will learn far more at the casting, loading, and shooting bench than you ever will at a computer bench.

  19. #99
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    Quote Originally Posted by goodsteel View Post
    OK, I was obviously confused about the terms.

    I'd still like to know how anybody knows for sure that there is anything more than carbon and oxidized metal in the dust we scrape off the top of the melt.
    I'm obviously very confused as well on where the burden of proof lies when a theory is stated as fact.......
    Geez, I'm about to give up. Tim . . . It is not theory. It is the science of metallurgy. Period. Exactly what we are trying to tell you is taught in universities around the world and it is not taught as theory.

    Rick
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  20. #100
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    Quote Originally Posted by btroj View Post
    Obviously someone is held back by the basic chemistry knowledge threshold.

    Tim, if I asked how you know for certain something you machined was precise what would you say? Part of it would be that you KNOw what you are speaking of. This is no different.

    Some of us have specific knowledge in specific areas beyond what the average forum member knows. At some point you can either trust that knowledge or you can go down a different path.

    I choose to trust my education and experience as you trust yours as a machinist. The fact others fail to grasp the basic concepts is not my problem, it is theirs. Arguing with those who don't understand the concept being discussed borders on ridiculous. I suppose I just need to come to grips with the fact that some people are never, and have never, been wrong.

    I apologize to Don Quixote for steppng on his toes, I should know better than to tilt at windmills.
    See, that's not true at all! As a machinist, everything I do is double and triple checked by people with measuring equipment. If I told somebody to just "trust me, my parts are always right" they'd laugh in my face. And let me tell ya, it really sucks when the guy in R&I holds his micrometer different than you do and scraps a tight tolerance part. Happens all the time.
    In my world, Theory and deduced outcomes are good for......well.....crumpling up an fluxing your pot with LOL!
    Tim Malcolm
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