Flux question:

[USAFrox]

Ok, I've been searching around in the forums here trying to learn more about smelting, casting, you name it. When I started out, I began by using candle wax as my flux. I've since learned here that the general consensus is that sawdust is considered one of, if not THE best flux available. Generally it is mentioned as simply "sawdust", or "reptile bedding", etc, but sometimes people get specific and say "PINE" sawdust. My question is, why pine, specifically? Is there something about pine sawdust that makes it superior to, say, oak sawdust?

The main reason I ask is that I was going to clean out my woodworking machines (which is where I store my used sawdust, don'tcha know), and then thought about the fact that my machines will have plenty of pine sawdust, mixed with oak sawdust, poplar sawdust, and maple sawdust. That got me to thinking.

Any reason behind folks saying specifically pine sawdust? Or is any sawdust just as good as any other sawdust?

[Bent Ramrod]

Pine has a lot of resin in it, which might help the fluxing action. (Somebody used to advertise a flake resin flux, IIRC.) However, any wood dust seems to work. I just pick the stuff off the floor and brush it off my sander and dump it in the pot. It's usually a mix of walnut, maple, pine, oil drips and whatever. It works OK. Except that sawdust could be obtained as a free byproduct, I don't think it's any more effective than wax, bullet lube, resin, Marvelux or oil in its fluxing action. I think the low cost is the main reason it's recommended for commercial casting businesses.

[ReloaderFred]

Sawdust is used because it doesn't leave a lot of residue in the pot. Different kinds of wood give off different fragrances, too. Some prefer the smell of pine, some oak, some alder, etc. It all works, as long as you stay away from some of the exotic tropical woods, which give off poisonous smoke........ I use whatever I have, which may be pine, spruce, oak, etc.

Hope this helps.

Fred

[leeggen]

Get the book "From Ingot To Target" it is free on line. It tells about fluxing and such. Tells what is and is not a flux, good reading for casters.
CD

[detox]

I get good consistant boolit weights using parafin. Weights are on par using sawdust also, but i have discovered that sawdust will find its way to the bottom of bottom pour pots which will result in dirty boolits. The chard sawdust will get trapped between melt and bottom of pot. I have since stopped using the sawdust and switched back to parafin (candle wax) in my bottom pour pot.

[detox]

Printing shops would never flux using sawdust...it would stop up their linotype machines. Vita Flux was designed to flux linotype vats, so it should be good enough for casters also. I have used Vita-Flux and it appears to be some type of wax, but seems to do just as good as candle wax or beeswax.

[Bohica793]

Printing shops would never flux using sawdust...it would stop up their linotype machines.

Since flux is typically skimmed off along with the impurities it is meant to filter, this statement really doesn't make sense to me, but I am not in the printing business. Just an observation.

I use sawdust exclusively for flux. I tried paraffin and found it to be highly flammable and not very pleasant to smell or work with. It also helps that my neighbor is a woodworker, so I have an inexhaustible supply.

[USAFrox]

I appreciate all the answers and information!

[geargnasher]

Boolit casters typically use dirty, contaminated scrap from whatever source we can scrounge up, and that sort of stuff needs special attention to make the best boolits. Clean alloy like nuclear medicine shields or foundry alloy doesn't require as much cleaning.

We need to do three things to our alloy: Clean, reduce oxides, and flux.

Cleaning is accomplished by mechanical action, stirring and skimming dirt, sand, steel clips, rust flakes, copper jackets, whatever. A slotted spoon is adequate.

Oxide reduction is next. We need to deal with the oxide dross formation on top of the metal, whether in smelting pot, or a freshly-melted casting pot full of clean ingots. Boolit alloy dross is very rich in valuable tin, so we need to turn it back into useable metal rather than skim and toss it. The opposite of oxidation is a chemical process called "reduction", so if we induce a reduction/oxidation reaction on top of the metal, we can save the scum. Combustion is a redox reaction. Anything that will burn will trade electrons with the oxidized metal, sort of "stealing" the oxygen and freeing the tin and other metals from the scum so they go back into the alloy. Grease, wax, oil, sawdust, anything like that will work to reduce oxides, and if your alloy is clean of other contaminating metals waxes work fine for this job.

Now, about Fluxing. This is the part that seems to confuse everyone. If your alloy came from wheel weights or other dirty scrap, it likely contains a bunch of other metals that don't cast very well and mess up the flow, or FLUX, of the alloy. This makes it tough to cast good boolits. Things we want to get rid of are zinc, aluminum, iron, calcium, and a few others. Since what we want to get rid of is all pretty much more difficult to reduce than lead, tin, and antimony, we can remove it through adsorption. With a "d". Things that work really well at removing the oxides of contaminating metals are molten borate glass and the carbohydrates in wood. Wax won't do it. The problem with borates (such as Marvellux) is that they don't reduce any of the oxides at all, including tin, they just adsorb them and remove them from the alloy. If you want to save your tin/antimony/bismuth/lead oxides, use sawdust because it saves the good stuff and adsorbs the bad stuff so it can be skimmed and thrown away with the ash when it has finished burning.

So again, sawdust, being a hydrocarbon, will also reduce tin/lead/antimony oxides we want to save while adsorbing the remainder of the junk we want to remove and capturing it in the ash. Two for one, so to speak. Resiny, pine sawdust, particularly sappy yellow pine, is one of the best reducant/fluxes I have ever used because the resin is such a fine and quick sacrificial reducant, quickly reducing the good stuff so it won't get adsorbed, but leaving the oxidized trash metals for the carbon to soak up as the wood chars.

Sawdust and ash cannot get below the surface of the melt and cause problems unless you drag it down there physically so that it gets trapped below the surface tension of the alloy at the bottom of the pot. Carrying ash down there on the end of a fresh ingot, a handful of sprues, or by scratching around on the bottom of the pot with a wooden stick are the principle ways of getting ash junk on the bottom where it will migrate to the spout and cause inclusions in the boolits. Use common sense and it won't happen. A wood stick is the bee's knees for scraping all the stuck, baked dross off the sides of the casting pot, it reduces oxides on contact.

Gear

[HARRYMPOPE]

scrape off crud,then cast bullets.Sometimes i will ad a dab of beeswax and skim again before casting,that's it.Have done it this way for quite a long time and done well in matches with bullets cast as such.You can overthink this stuff and spend more time on theory and less time at the range shooting to see if any of this matters.Many of the top competitive shooters that beat the **** out of me are in the stone-age with current cast bullet "theory" but keep winning.

George

[HARRYMPOPE]

Printing shops would never flux using sawdust...it would stop up their linotype machines. Vita Flux was designed to flux linotype vats, so it should be good enough for casters also. I have used Vita-Flux and it appears to be some type of wax, but seems to do just as good as candle wax or beeswax.

actually they often used the wood end plugs off of paper rolls on a rod to flux and stir.it would boil and spit like crazy.At least that's how my dads shop did it when i was a kid.

[USAFrox]

Thank you for that extremely useful explanation, geargnasher! I've never had it explained to me that simply before. As a person who likes to understand the how's and whys, you really made this stuff make sense to me (finally).

[John Boy]

http://en.wikipedia.org/wiki/Rosin

[geargnasher]

scrape off crud,then cast bullets.Sometimes i will ad a dab of beeswax and skim again before casting,that's it.Have done it this way for quite a long time and done well in matches with bullets cast as such.You can overthink this stuff and spend more time on theory and less time at the range shooting to see if any of this matters.Many of the top competitive shooters that beat the **** out of me are in the stone-age with current cast bullet "theory" but keep winning.

George

Your post does nothing to consider the context in which others may be attempting to make boolits, or shoot them. Context is what makes the difference between what works for you and what may or may not work as well for someone else. What is so terrible about having a little knowledge and understanding about alloy maintenance?

Gear

[JonB_in_Glencoe]

Boolit casters typically use dirty, contaminated scrap from whatever source we can scrounge up, and that sort of stuff needs special attention to make the best boolits. Clean alloy like nuclear medicine shields or foundry alloy doesn't require as much cleaning.

We need to do three things to our alloy: Clean, reduce oxides, and flux.

Cleaning is accomplished by mechanical action, stirring and skimming dirt, sand, steel clips, rust flakes, copper jackets, whatever. A slotted spoon is adequate.

Oxide reduction is next. We need to deal with the oxide dross formation on top of the metal, whether in smelting pot, or a freshly-melted casting pot full of clean ingots. Boolit alloy dross is very rich in valuable tin, so we need to turn it back into useable metal rather than skim and toss it. The opposite of oxidation is a chemical process called "reduction", so if we induce a reduction/oxidation reaction on top of the metal, we can save the scum. Combustion is a redox reaction. Anything that will burn will trade electrons with the oxidized metal, sort of "stealing" the oxygen and freeing the tin and other metals from the scum so they go back into the alloy. Grease, wax, oil, sawdust, anything like that will work to reduce oxides, and if your alloy is clean of other contaminating metals waxes work fine for this job.

Now, about Fluxing. This is the part that seems to confuse everyone. If your alloy came from wheel weights or other dirty scrap, it likely contains a bunch of other metals that don't cast very well and mess up the flow, or FLUX, of the alloy. This makes it tough to cast good boolits. Things we want to get rid of are zinc, aluminum, iron, calcium, and a few others. Since what we want to get rid of is all pretty much more difficult to reduce than lead, tin, and antimony, we can remove it through adsorption. With a "d". Things that work really well at removing the oxides of contaminating metals are molten borate glass and the carbohydrates in wood. Wax won't do it. The problem with borates (such as Marvellux) is that they don't reduce any of the oxides at all, including tin, they just adsorb them and remove them from the alloy. If you want to save your tin/antimony/bismuth/lead oxides, use sawdust because it saves the good stuff and adsorbs the bad stuff so it can be skimmed and thrown away with the ash when it has finished burning.

So again, sawdust, being a hydrocarbon, will also reduce tin/lead/antimony oxides we want to save while adsorbing the remainder of the junk we want to remove and capturing it in the ash. Two for one, so to speak. Resiny, pine sawdust, particularly sappy yellow pine, is one of the best reducant/fluxes I have ever used because the resin is such a fine and quick sacrificial reducant, quickly reducing the good stuff so it won't get adsorbed, but leaving the oxidized trash metals for the carbon to soak up as the wood chars.

Sawdust and ash cannot get below the surface of the melt and cause problems unless you drag it down there physically so that it gets trapped below the surface tension of the alloy at the bottom of the pot. Carrying ash down there on the end of a fresh ingot, a handful of sprues, or by scratching around on the bottom of the pot with a wooden stick are the principle ways of getting ash junk on the bottom where it will migrate to the spout and cause inclusions in the boolits. Use common sense and it won't happen. A wood stick is the bee's knees for scraping all the stuck, baked dross off the sides of the casting pot, it reduces oxides on contact.
Gear
A great explanation ! It helps me understand a few things I've read before, but forgot the 'WHY'. I'm mostly posting this quote, so it's easy for me to search for it again when I need to remind myself :)
Jon

[mold maker]

scrape off crud,then cast bullets.Sometimes i will ad a dab of beeswax and skim again before casting,that's it.Have done it this way for quite a long time and done well in matches with bullets cast as such.You can overthink this stuff and spend more time on theory and less time at the range shooting to see if any of this matters.Many of the top competitive shooters that beat the **** out of me are in the stone-age with current cast bullet "theory" but keep winning.

George


That's alright George. What ever floats your boat.
Gear explained the process, in detail, with background knowledge to back it up. What he said, is what I have found to be true, but didn't know why.
Thanks Gear, for putting in in terms, even I can understand. Anytime I can gain knowledge, it's a real bonus, especially in this hobby. To me, understanding Why things work, is often more important than the results.

[Mal Paso]

Your post does nothing to consider the context in which others may be attempting to make boolits, or shoot them. Context is what makes the difference between what works for you and what may or may not work as well for someone else. What is so terrible about having a little knowledge and understanding about alloy maintenance?



Gear

You're part of that "Round World" crowd aren't you? One of these days you'll sail right off the edge!


Excellent Post!

[w5pv]

One word of caution be sure that the sawdust is dry or the tinsel fairy may visit.I keep mine in a dry storage store room.If you have any doubt spread it on a cookie sheet and turn the heat to about 176 degrees in the oven for about 30 minutes

[geargnasher]

If you don't get the sawdust below the surface, no Tinsel Faery. Sprinkle it on top of the molten alloy and it'll be dry in a jiffy. Stirring with a wood stick, even one that's been kiln dried can make some very creepy rumblings down under the lead, but as of yet I haven't actually had it cause a steam explosion. That doesn't keep me from yanking it back out at the first sign of a rumble, though.

Gear

[Wayne Smith]

Once again, Gear, thank you. For one who's "B" in HS Chemistry was a pure gift your explanations are gold. 99% of my woodwork is hardwood so I haven't used a resiny stick to stir, but I can imagine at least a mini tinsel fairy. Years ago it was interesting when I swatted a wasp and it ended up on top of my melt.

[Three44s]

Nice job Gear!

The one thing I'll add that Gear usually covers:

He advocates using a metalic spoon for going deep to stir and scrape ..... the wooden stick higher in the melt. His suggestion has "cleaned" my act considerably!!!

It turns out that your stick will leave off carbon etc. and it will remain stuck under a pressing weight of the melt .... the spoon won't.

And as far as adding new items to the melt ..... whether it be a wooden stick or metal spoon or even placing a ingot mold under your spout ........ always pre-heat.

Best regards

Three 44s

[bangerjim]

Geargnasher.................thanks for the info! Great post.

Guys.................be careful where you get your sawdust. Getting it from HomeDespot or Lowes........it could/will contain wood from chipboard/particle board/pressure treated wood/etc. You do not want to burn or inhale some of the crapola used in those wood products. Heaven knows we inhale enough garbage the way it is!

Best bet is use your own KNOWN sawdust. Or get it from a buddy that has a shop and cuts know woods. I prefer walnut and alder, but also use mesquite (have three of the buggers on my property). Sappy pine is non-existent around here. Some use bedding chips from pet stores.
Others use spend walnut media from tumblers. Again......NOT a good idea......brass/lead/"stuff" in there from the casings!

And I use beeswax exclusively because I have a ton of it and I like the smell.

bangerjim

[ReloaderFred]

"Others use spend walnut media from tumblers. Again......NOT a good idea......brass/lead/"stuff" in there from the casings!"


I really hate to mention this, but we're fluxing "lead" here, aren't we?

Just sayin'.............

Fred

[USAFrox]

"Others use spend walnut media from tumblers. Again......NOT a good idea......brass/lead/"stuff" in there from the casings!"


I really hate to mention this, but we're fluxing "lead" here, aren't we?

Just sayin'.............

Fred

That's what I was thinking...

[JWFilips]

Gear,
Never in all your hundreds of posts explaining fluxing to us have you put it so eloquently! That was beautiful & so simplistic. You said it in a way that anyone could understand. That one post of yours should be a sticky in itself. You have just made the "simple act of fluxing" even simpler & I'm sure we all thank you.

And +1 on not using a wooden stick on the "bottom" of a bottom pour pot. Since I took you advise earlier this year I haven't had a plugging issue and no crud in the boolits ( something I was plagued with early on)

I made this cool little scraper from an old stainless steel ruler and some maple wood for a handle. I rounded the edges to match the bottom of my pot so I can scrape right to the edges and bottom effectively No more wood on the bottom of my pot.
81404

[Outpost75]

Printing shops would never flux using sawdust...it would stop up their linotype machines. Vita Flux was designed to flux linotype vats, so it should be good enough for casters also. I have used Vita-Flux and it appears to be some type of wax, but seems to do just as good as candle wax or beeswax.

+1 on Vitaflux! One stick fluxes A TON of alloy. A quick jab and withdraw of the stick into the melt does a 50-lb. pot! I made a fixture bolting a pipe cap onto a stick of broomhandle, to flux the melt for routineproduction casting, a pea-sized dab or a half dime thickness slice does 50 lbs. of wheelweights.

Great stuff. Most commercial casters running the Magma Auto-Casters use it. Therein lies the clue!

[geargnasher]

When I first read Mr. Fryxell's article "The simple act of Fluxing", I knew I'd found the thing that had been missing with wax "fluxing". Lots of experimentation proved in practice what he'd proven in theory, and I never looked back. Understanding the nature of the contaminants we often deal with in our scrap alloy and how to get rid of them, as well as managing casting pot temperature at an ideal level for the particular metal being used at the time, and how to effectively manage the inevitable oxide formation when casting or smelting has made my whole casting experience better, more effective, and a whole lot more fun. I hope learning a bit more about it will help many of you the same way.

Three44s, I did forget to mention the steel spoon, thanks for reminding me! A yard-sale SS tea spoon or table knife (or several) ground to a blunt tip is handy for scraping the bottom, but I like the machinest's rule scraper in JWFilips' pic above, too. The trick is to get something with a square point to really get at the bottom and bring the crud that finds its way down there to the sides where it can be drawn up and out of the melt.

Other things that work for a flux/reducant: Coffee (fresh, or dried, used grounds), Quaker oats, wheat germ, (really good but stinks), corn flakes, hamster bedding, plain corn cob (but beware, it holds lots of water and is difficult to dry), all manner of tree bark, tree leaves, dry grass clippings (don't use if you don't want to draw the attention of authorities or nosey neighbors), unsalted potato chips (the only useful thing I can think to do with such), peanut butter (probably mostly a reducant), and of course sawdust or wood shavings.

Watch the walnut wood, shells, oak wood, and western aromatic cedar, these woods among others can release toxic fumes with the smoke. I mentioned before how I killed every mosquito in my shop one summer night with a couple tablespoons of western cedar taken from the router table. It fluxed and reduced the alloy very well, but gave me a bit of a headache. Sawdust from pressure-treated wood is poison, as is formaldehyde from the glue in plywood. Just be careful and keep your senses about you when dumping stuff into molten lead.

If someone can kindly explain to me just exactly how Vitaflux works, chemically, and why it's a good alternative to sawdust, I would appreciate it. I like to use what works best, no reason not to unless cost prohibits it.

Gear

[bangerjim]

"Others use spend walnut media from tumblers. Again......NOT a good idea......brass/lead/"stuff" in there from the casings!"


I really hate to mention this, but we're fluxing "lead" here, aren't we?

Just sayin'.............

Fred

Yes, we are.......BUT.........

The crapola that is in well used walnut media is loaded with many nasty oxides of copper, zinc, lead, and whatever other "stuff" you can find in spent primers!

It is NOT a wise choice at all.

The amount of lead fumes you get from using clean flux is far less hazardous than using that stuff. Don't be cheeeeeep. Just throw it away!!!!!!!!!

Don't even breathe the dust that comes off it when dumping your tumbler.

This is not a "greenie" thing.......it is a medical thing.

Or......have fun getting your blood work done every year and being turned into the government due to high lead levels!

bangerjim

[Defcon-One]

I like pine sawdust. It smells great and works great, too!

One thing that was not metioned is that once the sawdust burns it forms charcoal/cabon which acts to further clean the mix. It absorbs any contaminants into its multitude of pores.

If you've ever melted down some SOWW and had to deal with the glue and backing, all melted into burning smoking clumps of lava, then you should try it again, but add a big handful of sawdust. The carbon from the sawdust mixes with the glue and absorbs a lot of it. It also bonds to it and makes it easier to remove from the pot.

[geargnasher]

DefconOne, I mentioned it loosely in post #9. The process of attracting and locking undesirable metal oxides within the structure of carbon is actually called adsorption, small but subtle difference as one of our resident egghead pharmacists pointed out to me a while back ;) I think the ash/carbon just plain ol' absorbs some of the non-metallic junk, though, like you say. Sawdust ash soaks up all manner of nasty junk including Alox residue, melted tar and elastomeric sealant from roofing lead, etc. Great stuff. After using a variety of wood shavings/sawdust I'm definitely with you on the pine, it's the best.

Gear

[ReloaderFred]

bangerjim,

I've been at this business for a little while, since 1963 reloading, and 1968 casting. I have my blood checked regularly and I'm in the low normal range.

I make my decisions based on science and experts in the field, not hype and hysteria. I've studied the lead "problem" from all angles and was instrumental in establishing a "Best Management Practices" manual for our range, which was given the seal of approval by the Federal EPA. I'm a delegate to the Oregon Association of Shooting Ranges (OASR), and one of our goals is to make ranges aware of lead issues, and how to manage them. I've talked to the EPA expert for lead on ranges, and with the CEO of SAAMI at our meetings several times. I have studied the lead issue, believe me.

Lead wasn't really an issue until the politicians in California got involved and put Proposition 65 on the ballot, and the unwashed masses voted it in. It wasn't based on science, but was rather based on politics and scare tactics, along with the desire of those in power to govern every aspect of our lives.

I personally use sawdust or woodchips for fluxing, but your blanket statement was hype. For one thing, ground walnut hulls don't absorb. They are hard and solid. They clean via friction, however they may become coated with a small amount of lead styphnate and carbon during the tumbling process.

Ground corn cob on the other hand, is porous, and absorbs impurities. It polishes in two ways. The first is taking in the impurities, such as lead styphnate and carbon from burned powder, and the second is by friction. It gives a higher shine because it's softer, just like using a piece of flannel, rather than rough canvas, to polish with.

geargnasher has laid out the scientific reasoning behind sawdust as a flux, with no hype, or internet rumor. That's the way I like to see explanations, based on fact, not fantasy.

Now, if you want to dress up in a HazMat suit when handling your tumbling media, and it makes you feel better, by all means do it. Just be assured that you're getting as much, if not more, exposure when you actually fired those rounds downrange......

I'm not trying to pick a fight, just sort the chaff from the grain.

Hope this helps.

Fred

[Defcon-One]

Gear:

I understand that Charcoal will adsorb gases. Not so with solids or liquids. It absorbs them into its pores! Of course, I could be wrong!

Either way, it is clear that we agree, it sucks them up and removes them. Which is exactly what we want.

I also think we are right that Pine Sawdust is best. Probably because of all the pitch and rosins it contains. It smells pretty darn good, too and it is easy to make.

[geargnasher]

Defcon-One, adsorption is completely, totally different from absorption, I only used the sponge analogy (absorption) to make it easier for others to understand. Adsorption is a surface action only where bonds between liquid, solid, or gas are created by molecular attraction (i.e. ionic bonds, covalent bonds, electro-static bonds, Van Der Waals bonds, etc). Adsorptive media with a higher surface area does best, and activated carbon has an incredibly high surface area. We aren't creating true activated carbon, but the structure of the carbon from wood particles that forms as the wood chars is very porous and absorptive to metal oxides.

Charcoal will adsorb lead, tin, and antimony oxides as well, so it's best to use sappy sawdust (or a mixture of sawdust and wax/oil/lard whatever) which will easily reduce the stuff we want to keep and prevent it from being adsorbed as the sawdust turns to carbon. Sawdust and grease/wax/oil are less effective at reducing the contaminant oxides at smelting/casting temperatures and therefore leave the contaminant oxides of metals such as aluminum, calcium, and zinc in their un-reduced form so they can be adsorbed by the forming carbon. This is why activated charcoal, bbq briquets, and other forms of carbon aren't effective reducants and can "over-flux" by removing oxides of good metals if they aren't first reduced by other means.

Gear

[flintlock62]

I use beeswax to flux my lead. One caution I would mention, is some woods can give off toxic fumes, such as purple heart.

[geargnasher]

Flintlock62, welcome aboard the forum! Now this isn't meant to be mean, so don't take it that way, but consider that "I use beeswax to flux my lead" is not really an accurate statement. Scroll up and do some reading, lots off good info from a lot of members here. Beeswax is fine, but it only does certain things.

Gear

[flintlock62]

I'm not taking it as being mean. I haven't cast boolits in a coon's age, then then I didn't do too much of it. I was told beeswax was the best way back when. I'm about to start casting again because the price of off the shelf JHP's is getting ridiculous. I am going to give saw dust a whirl.
Thanks for the welcome!

[geargnasher]

I used beeswax and candle stubs for nearly 20 years because that's what I was taught, too. It does a great job of reducing oxides to elemental metals and getting rid of oxide scum, but like a lot of people nowdays I use all sorts of random lead alloy scraps such as I can scrounge up, and together with the multi-recycled alloy in modern wheelweights, there's all sorts of stuff in there that can cause casting problems, and sawdust and stirring with a wood stick helps remove it.

When I first tried sawdust, I did an experiment on a 400-lb batch of alloy I'd smelted and fluxed with wax that just didn't seem to cast very well. I never figured out why, but after re-melting all the ingots in my big smelting pot and cleaning repeatedly/stirring/ladling alloy through the sawdust layer and re-pouring the ingots, the alloy cast great! The first two or three heavy sawdust fluxings removed handfulls of clumpy, silvery stuff that looked like burnt aluminum foil, and subsequent fluxings would burn to a fine ash and not seem to pull anything else out. The sawdust definitely pulled out something that was making the alloy tough to cast with, I suspect aluminum and calcium. I've been "sold" on sawdust ever since, and it really does well at keeping the sides of the pot clean and as an oxide barrier if you just leave a sawdust layer to char down on top of the bottom-pour furnace. For ladle casting, I flux with sawdust and skim, then use beeswax or paraffin periodically to keep the tin "reduced" and in solution.

Gear

[eljefeoz]

Thanks, Gear for the reiteration
Just hand ladled a batch for 45 today (posted up here too)
Alloy was fluxed multiple times with cedar/beeswax& BBQ fat, poured into muffin trays.
Today, reaching liquidus, I had some square shanked boolits that tumbled out of the mold effortlessly and-in a while, had a collection of that shiny dross.I fluxed again with cedar, and used beeswax periodically.
I thought if the initial smelt was fluxed "adequately' , the alloy would pour well.What I found today was, it doesnt hurt at all to keep things happy with wood and a sacrificial reductant.