fluxing- why bother?

[woodsie57]

melted about 100 lbs. of lead yesterday, mostly into muffin pans, also made 300 or so swc's , for .38/.357 use. Found that, after skimming the crud from the top, casting went well. Adding the clump of beeswax and stirring, only had the effect of ,well, a black film of melted beeswax on top. Push it outta the way with the ladle and cortinue casting. No harm done. But, whats fluxing really supposed to do? And, since it seems unnecessary,why bother? Bullets seem the same either way.

[wallenba]

It gets a lot of the impurities out of the alloy that will affect the BHN (brinnell hardness number), and helps keep the alloys in the lead more homogenous (well blended). Also lead oxidizes on the surface of the pot changing molecular structure which affects how well the alloys bind together. This is how I understand it (not an expert).

[10mmShooter]

Woodsie,

Fluxing really only provides two benefits.....

1. minimization of oxidation on the surface of the melt(requires something other than lube or beeswax)

2. removal of "junk" from the melt and get it to the top for skimming so it doesnt get in your bulllets creating voids or "heavy spots". (you dont really need anything to for this, just skim the garbage off the top, beeswax and lube do help for this.

Now.....heres things to consider, the more you disturb the surface of the melt the more you are allowing the lead to oxidize(this oxidiation occurs to lead in your alloy when its exposed to oxygen, so you are always losing microscopic amounts of lead to oxidation during casting, this why lots of people try to avoid disturbing the surface of the melt to minize this oxidization.( I use Frankford Asrenal Flux, it contians boric acid to prevent oxidiation) The oxidation is really just lead oxide but its an impurty that you is best kept out of you bullets

so...does fluxing really matter....thats for you to decide if you lead is "relatively clean" just scrap the the junk of the top and dont worry about it. Even though I have the real casting flux if you are moving through you lead quickly casting...I would not worry about the losses due to oxidation, If I see something I dont like I pick it off the surface and continue.

The commercial flux are inexpensive about $10 for a little tub that will last a long time.

[montana_charlie]

melted about 100 lbs. of lead yesterday,

Found that, after skimming the crud from the top, casting went well.

But, whats fluxing really supposed to do? And, since it seems unnecessary,why bother? Bullets seem the same either way.
If I was casting with lead, I wouldn't flux either (if I knew the metal was clean to start with).

But, since (unlike you) almost everybody uses alloys, there is interest in not losing 'other ingredients' due to oxidation.

Tin oxidizes faster than lead does, so the tin oxides on the surface make up a larger percentage of your total tin content than is true for the lead content.
'Fluxing' is what we call it, but 'reduction' is the process of turning an oxide back into the original metal. Returning tin oxides to a useful state is the reason people flux while casting...when using alloys.

CM

[SciFiJim]

a black film of melted beeswax on top.

Also, this would act as a barrier to slow down oxidation. I ladle pour as well, so I too, push aside the black film to dip.

Eventually you will have a build up of stuff on the side that needs to be removed or reduced back into the melt. I skim it off and save it in a metal can. Later, when I have a good amount, I will remelt it with some clean alloy and flux heavily with sawdust. As the sawdust burns, it pulls the oxygen from the hot oxides, returning them to elemental form.

[chevyiron420]

melted about 100 lbs. of lead yesterday, mostly into muffin pans, also made 300 or so swc's , for .38/.357 use. Found that, after skimming the crud from the top, casting went well. Adding the clump of beeswax and stirring, only had the effect of ,well, a black film of melted beeswax on top. Push it outta the way with the ladle and cortinue casting. No harm done. But, whats fluxing really supposed to do? And, since it seems unnecessary,why bother? Bullets seem the same either way.

i asked this very same thing a long time ago and the good people gave me alot of good answeres including some debate about the possibility of returning oxides to usable alloy. unfortuetly afterwards i was just as confused as i was at the start. somehow just doing it teaches a person what to do. here is my very unsientific opinion. i find that fluxing doesnt always work for me. i dont know if its temp or what. there are oxides in your alloy, lets just call it dirt. after fluxing if the dirt is a dry grey powder the fluxing worked. scoop it out and continue. if the dirt is a silvery mush, it didnt work, do it over again. i dont think you can reclaim oxides, but the fluxing will cause it to separate from the alloy so you can remove it well, and if you dont get a good flux the dirt will remain suspended in the alloy and it will end up in your boolits. i also believe that fluxing keeps your alloy well blended. you will notice when ladle casting after a wile silver metal will start clinging to the ladle and actually start glogging up the ladle hole. if you stop and re flux it goes away for a wile.

[Calamity Jake]

Been casting boolits for over 30 years, I have always fluxed and always will!!
Why? Because it removes dirt, dirt that I don't want in my boolits or casting pot, plus it reintroduces the oxided tin surface layer.
After you have smelted your lead/WW or what ever and skimmed all the visible dirt and crud and you think it is clean, sturr it with a stick, any stick as along as it is dry and see what you get.

[Bluehawk1]

I've noticed when I try to flux with a commercial flux powder you normally can't get it to go anywhere, even with stirring, except on the top of the melt. I now put about 1/2 teaspoon in my Lyman ladle and drop it to the bottom of the pot and stir from there.
Is that really doing any good or should I just spoon the flux onto the top and stir??

[Heavy lead]

Alright, I've only been casting for a couple of years. I've been soldering, brazing, and welding all my life and have come to know what the definition of flux or fluxing is. I believe now there is more definitions than one to fluxing. Now to my understanding of reading I did before I casted my first boolit was that fluxing (I started with a small dab of 50/50 and pretty much always use it still) not only brought impurities out but also reduced the surface tension and allowed the boolit to fill out better. Maybe it is my imagination but I believe this to be true. Sometimes I will have a pot all melted up to temp and the fillout is just terrible, generally I notice the surface of the melt is not flat, but rather curved slightly humped in the middle not filling out the cylindrical shape of the pot, as soon as I drop some 50/50 (light it off with match if it doesn't light itself) stir well and wala, the surface is flat and it also pours beautiful boolits. At this point skimming is not needed as it is a clean melt. Is this my imagination? Or is this really a cause and effect that appears to be what it is?

[SciFiJim]

I know that tin reduces the surface tension of melted lead. Is it a possibility that the flux returns oxidized tin from the surface to the melt, thereby reducing the surface tension. Any metallurgists want to chime in on this one?

[Heavy lead]

I know that tin reduces the surface tension of melted lead. Is it a possibility that the flux returns oxidized tin from the surface to the melt, thereby reducing the surface tension. Any metallurgists want to chime in on this one?

Good thought, maybe. I'm just curious if this is all in my head to be honest.

[felix]

Correct as stated. No, it is not in your head. ... felix

[waksupi]

I've noticed when I try to flux with a commercial flux powder you normally can't get it to go anywhere, even with stirring, except on the top of the melt. I now put about 1/2 teaspoon in my Lyman ladle and drop it to the bottom of the pot and stir from there.
Is that really doing any good or should I just spoon the flux onto the top and stir??

Forget the commercial flux. Get a good dry stick and stir the melt, that works better than anything else you can add.

[mroliver77]

I have some unknown alloy that is nasty. It does not like to fill out molds well or I will get a weird almost corrosion looking inclusion on the sides of some boolits. If I flux the daylights out of it I can get good boolits. wooden stick and or sawdust is not enough. Flood it with wax and it will cast well for a while. It really does make a big diference. It also seems as if I flux at the lowest temp possible it cleans this alloy better.
Jay

[Bret4207]

DO what Ric says. A good dry stick of pencil size or larger works better than any flux I've tried. Scrape the bottom and sides, stir the melt around, work it around the alloy. The crap will float to the top, the oxides that will rejoin willingly will rejoin and then you can remover the crap floating in top. Save the garbage and remelt later in a separate pot, I use my old Lyman 10 lbs-er, and stir that stuff around with a stick. You get more alloy out of that stuff.

FWIW- When I went to a stainless pot my dross accumulation dropped by half at least.

[45r]

I cut foot long sticks that are about 3/8 inch thick at top and going to a point at bottom and about 1 inch wide.They look like a long wedge.I stir some saw dust in with it and scrape the bottom and sides.I remove the ash and put in some tin and stir in some printers flux with the stick.I get alloy that is very clean and fills out very well,so well it fins if too much pressure from my RCBS pro-melter.I don't let the pot get less than half full to keep from getting tiny bubble holes in boolits.I flux about every half hour with stick and printers flux till I"m done.I add tin when needed and don't let the pot go over 750 degrees.If I see the mold is starting to get too hot that is when I flux sometimes to let it cool and I wipe the smoke off my molds and resmoke them just before pouring again.Just a little smoke from a barbecue lighter really helps fill-out for me.I think fluxing is very important and it does help keep the dirt out of your boolits.After you stir with a wedge stick press the crud against the side and see the dirt and ash there.You can get the dirt out and leave the tin and antimony in.I use an old silver spoon for getting the dirt out.

[PatMarlin]

The flux threads always get my curiousity up about you guys who swear by the stick and always jump in and say nothings better. Have you tried every type of flux including mine? Hmmm? ...:mrgreen:

I normally don't post in these threads as I don't hardly make a dime on my flux when I add up the time it takes to mix, box and ship. Not really worth my time, but it does work remarkably well, and it's a good use of a byproduct as I hate to waste anything so to that end it's worth it.

I'll bow out now ...:mrgreen:

[montana_charlie]

Pat,
I expect that your flakes would do a fine job. But I would only use them if bottom pouring, so I could just leave the residue on top of the alloy.

When ladle casting, you can use sawdust (or flakes) for oxide reduction, but you then have to scoop it all out to continue. The stick does a good job, and and the small amount of residue can be shoved aside, if you don't want to stop long enough to scoop it out.

So, just like you have to differentiate between rifle shooters and revolver guys when talking about bullet fit...what is most convenient for 'fluxing' depends on how the writer casts.

Since I'm not smart enough to get a good bullet from a bottom spout, I'm not qualified to use your flakes...

CM

[Junior1942]

Fluxing mainly gives you a satisfying puff of smoke through which you can mutter a chant to the gods of the silver stream. Other than that, it's a waste of time in my considerable experience. I haven't fluxed in maybe 30 years and many thousands of good cast bullets.

Dirt, by the way, is much lighter than lead and floats by itself to the top of the melt.

[PatMarlin]

I'll bow back in momentarily... :bigsmyl2:

A bit of history...

Actually, the reason I started experimenting with my type of flux was not due to finding comments on the net, or comments from other casters no... What peaked my interest on the subject is an old book I have here on metallurgy and foundry work that was published near the turn of the century.

One chapter is devoted to fluxing, and fluxing with a forest product in particular and goes into great detail on species, size, and form of the material and how well it worked for those guys who by all accounts were the premiere experts of not just their time, but probably of all time on the subject.

Just so happens what forest product they describe is the very forest product I have here. I tried to find the book this morning and quote from it, but it was not on my bookshelf, but I will run across it sooner or later.

[PatMarlin]

Then as time progressed I noticed a difference by fluxing this way with my boolits and continued to use it, but it wasn't until I was down in Southern Cal visiting Dept Al, and I had brought him a bag to see what he thought and see if it was just my imagination.

He raved about it and said it was by far the best flux he had ever used, and it was then I figured I was on to something. Till this day I have not had any other feedback but comments on it's stellar performance.

[montana_charlie]

Dirt, by the way, is much lighter than lead and floats by itself to the top of the melt.
Last week I would have wholeheartedly agreed with that statement.

But, three days ago, I was melting down some x-ray slielding that still had a small amount of paper and gypsum (sheetrock) attached.

After the whole thing had melted, and burned, and smoked, I cleaned the surface thoroughly using a large aluminum 'scoop'.
For no particular reason, I scraped the bottom of the pot and a large amount of black carbon(?) came to the surface. So, I continued to scrape until I could find no more. I got quite a lot.

I was really surprised that stuff didn't float up on it's own...and required scraping to 'dislodge' it.

CM

[SciFiJim]

Charlie,
That's what I get when I process radiator shop dross. The weight of the lead holds the dirt onto the bottom and sides of the pot and requires a lot of bottom fishing with a slotted spoon to get out. I wonder if attaching some sort of vibrating device to the pot would cause the dirt to float. I'll have to think about it some to figure out a way to not melt a power tool attached to the pot.

[45r]

Dirt doesn't always float to the top.That is why it is good to scrape the bottom and sides when fluxing.I read that sawdust was considered good flux by printers and they should know.They also use a wax type flux also.I use both and feel it isn't a waste of time.Sure you can make usefull boolits with out it but the alloy won't be as clean and be harder to get good fillout.Tilt the smelt pan you use when it is low on alloy and see all the dirt that didn't float to the top.

[Dollar Bill]

Dirt doesn't always float to the top.

That's why it's difficult sometimes to get good results with a bottom pour pot, especially if you render ww and other "raw materials" in your casting pot. Not only does garbage stick to the sides and bottom, it sticks to the flow control / shut-off rod and enters the silver stream at inconvenient times.

[gwilliams2]

I usually use wax, but I've found that paint mixing sticks work well for mixing and act as an additional flux as well. Paint mixing sticks normally come in two differnt sizes and the best part is that they're free...

[45r]

Your right dollar bill that there is a possibillity of crud slipping out a bottom pour and a dipper often does better for long heavy deep groove boolits to get good fill-out from what I've read.Speed and convenience is where the bottom pour comes into it's own.Any boolit that doesn't look good goes in the sprue pile and remelted when I cast.Fluxing will help keep the crud ,dirt and dross to a minimum though and help with tin and antimony loss and help those boolits come out looking good.I like to keep my alloy flowing like water and not like mud.If you got the flow adjusted right and the alloy has enough tin and is clean you can pour out some very good boolits with a bottom pour.Some day when I can get enough time I'm going to try ladle casting on my big 45-70 boolits to see if it is any faster or better,I get some rejects on them sometimes but hardly ever on the 320 grain and less of any calibur boolits.I like my pro-melter from rcbs and they stand behind there product for a lifetime of use.I don't know why some don't flux when it is so easy to do.

[454PB]

In the case of "smelting" wheelweights, you really don't have to worry about fluxing. Unless you cleaned every one with degreaser, there's enough grease on them to do the fluxing whether you want it or not.

[Bret4207]

Dog pee too 454, don't forget the fluxing characteristics of dog pee!:bigsmyl2:

[Whitespider]

When I first started casting (just 4-years past) I’d read these “fluxing” threads with great interest. Some do, some don’t, some use wax, bullet lube, saw dust, sticks, used oil, new oil, dried leaves, potatoes...... the list went on and on, it all seemed like black magic.

But the question was, “why bother?” When I’m castin’ I’ll notice that a lot of thick metal is starting to stick to the dipper and shortly after that the mold fill-out begins to go south. If I flux just after that metal is beginning to stick to the dipper I never get the fill-out issue, so to say that fluxing is “a waste of time” (Junior1942) just don’t sit right with my limited experience. There is some advantage to fluxing, no doubt in my mind, but I’m not willing to form an opinion on necessity..... yet.

All the dirt don’t float to the top, flux or not. I flux often and I’ve still got lots of dirt on the bottom when I empty the pot (which I do after every casting session), I’m not even sure fluxing aides in the removal of dirt, but it sure reduces surface tension of the molten metal.

[Calamity Jake]

In the case of "smelting" wheelweights, you really don't have to worry about fluxing. Unless you cleaned every one with degreaser, there's enough grease on them to do the fluxing whether you want it or not.

When starting with a cold smelting pot full of WW all that grease is burnt off before the WWs get melted, so how is is going to flux anything?[smilie=b:

[cajun shooter]

First Let me say that Pat's flakes do a wonderful job. I love the smell that they give off. After my first flux I skim it off and then add more to leave on top. It's a shame that I can't do the same when using my Wagge pot to laddle pour. Pat, why don't you look into a binding process that would allow all the ladle pour people to stir with a stick. JMOP

[PatMarlin]

Clever idea CS.

I catch enough flack from non believers. Next they will be calling me a "dip stick" ...:mrgreen:

I remember when I first started this. It even started a battle over on another forum, and I was accused of everything in the book for trying to sell such a thing. Not like I was selling Alder chips for salmon.. :mrgreen:

Now go to the thread on my flux (link below) and look at all the seasoned casters from RanchDog to NVCurmudgeon Bill. They don't post something unless they mean it, and that's a partial list of users.

As I mentioned earlier, I don't usually chime in on these flux threads, and I have the utmost respect for the members, and their opinions here. It's like fishing- if you believe in it, it works. If you don't, you're not going to catch any fish with that rig.

....:Fire::drinks:

[leadman]

I used to use Marvelux to flux in my bottom pours. I also had alot of problems with the spouts plugging up and rust. Rust in Phoenix is a rare thing normally. The Marvelux forms a hard slag on everything you don't scrape it off of when it is hot. It also seems to suspend in the melt and is visible on the sides of cast boolits. No longer use this.
I have been melting lots of lead lately, probably well over a ton in the last 5 weeks or so. I found that the wood stick will work if the lead is clean to begin with or was fluxed clean with the candle wax I use. When the lead ingots are older and covered with oxide it is not as effective. Then I have been using the candle wax which works good.
I had some floor sweepings from my garage that had little pieces of lead from splash in it along with dried grass and leaves. Threw this in the big pot I use to melt lead to make ingots. Cleaned up that pot real well.

[badgeredd]

Pat,

For the record, I love your flaky stuff. I also found that a piece of resinous pine stick used to scrape the sides and bottom of my bottom pours in conjunction with your flakes gives me a CLEAN mix.

Also I found out that when I smelt my babbitt or WWs that your flake does a great job of getting a lot of the dirt/crud out of the melt for clean ingots.

I just thought of an idea to please some of the folks. You could add a couple 1" square sticks of the piney stuff to a box of your flake!

Edd

[waksupi]

I think Pat's flakes are an excellent substitute for kitty litter on top of the pot!

[docone31]

I had thought, from an enlightened position, and with all my might, melting old roof boots the tar would make a flux! Content to tally forth with great speed, the pieces of roof boots melted, the tar made much smoke, crud floated to the top, and all that stuff.
Well, the melting started slowing down, untill it took all day to melt some, and then nothing at all. Lots of smoke, no melting!
I brought my pot into the kitchen, cranked up the heat, ladled lots out into ingots, then let the melt "cure". I brought the now cold pot outside and turned it upside down as usual.
Nothing! The melt stayed in the pot! I ended up haveing to heat the pot to pop out the melt!
The tar had made an insulating layer on the bottom, staying quite thick. Up the sides, on the bottom, I had an issue indeed.
I put the pot into the freezer and the tar was able to be chipped off. Slowly. I took some time.
Once the pot was freed up, the melting again went at good speed!
Crud does go to the bottom. It does stay there. With my Lee pot, I have an old long screw driver. I scrape the sides, and bottom of the pot constantly. I get the blade hot enough I can scrape the lead off the tip.
Once tar turns into pitch, it is miserable stuff to eject from the melting pot.
From that point forward, I use a melt in the pot to start with then toss the pieces onto the melt itself. That keeps the tar on top. I skim with a cheap stainless steel spoon with lots of holes. The lead drips out, the crud stays in the spoon.
Not a perfect system, but it works for me.
With wheel weights going out of vogue, I have my stock of WW ingots, and I now have lots of roof boot lead. I will be blending more now. No more pure WW castings. I have been adding tin. 2% and I get good castings. Good size, hard, and little leading.
I think, it will be simpler to rebarrel than get good WWs pretty soon.

[Lloyd Smale]

im with junior for the most part. Ive casted well over a million bullets and have been told by a few people that they were pretty darned good and i seldom flux. Maybe once before i start a casting session but not even that all the time. I flux my lead to clean it when im smelting and if its in ingots its clean and doesnt need flluxing . Personaly i think overfluxing is alot worse for making quality bullets then not fluxing at all.
Fluxing mainly gives you a satisfying puff of smoke through which you can mutter a chant to the gods of the silver stream. Other than that, it's a waste of time in my considerable experience. I haven't fluxed in maybe 30 years and many thousands of good cast bullets.

Dirt, by the way, is much lighter than lead and floats by itself to the top of the melt.