What kind of flux do you prefer and why

[DickelDawg]

I've only been casting for a month or so but it seems from what I've read that pine sawdust and paraffin seem to be the preferred flux. I've tried both and I'm not overly impressed with the sawdust flux. Can I get some feedback on this subject from some of you who have been casting for long enough to have an intelligent experience. No offense intended.

[btroj]

Not impressed how? It isn't intended to impress, just work. It does generate a fair bit of debris but I ignore that as the debris is required for the work to get done.

[DickelDawg]

OK, btroj. Just looking for some experienced input. Thanks. Do you think cedar sawdust would work OK?

[ShooterAZ]

I use sawdust for rendering WW and range lead in a cast dutch oven. This stuff is usually really dirty and the sawdust does a very good job of getting the crud out of it. Sometimes it takes a number (2-3) of fluxes to get it clean. I just use paraffin or beeswax in my RCBS pot, because that alloy is already clean. This subject comes up often and sometimes gets controversial. This is what works for me.

[jcren]

I haven't used sawdust, I use borax (boric acid powder in the laundry isle) for heavy cleaning/smelting. At that temp, when stirred vigorously, it bonds with anything it can to form a salt ash. Wheel clips and dirt wind up trapped in a crunchy, easily skimmed layer floating high on the surface. Parafin is for recombining oxides, such as tin, that form on the surface of clean metal during casting. Just what works for me.

[country gent]

I flux with both, sawdust ( pet bedding) and parrafin or beeswax. I sprinkle a decent amount of sawdust on the alloy and let it start to char and add a small amount of wax to it . The wax will normally ignite and I mix the lead thru the charred sawdust thoughroly. It does a great job and the carbon from the sawdust helps to hold the impurities for removal. The mixing motion you usse makes a diffrence as just stiring letts the flux material sit on top. You want to srap the sides good and raise the alloy up and thru the sawdust and push the sawdust down thru the lead. When done you end up with a surface on the alloy that looks like a mirror.

[DickelDawg]

That's fantastic. Just the kind of info I was after.
Thanks gentlemen,
Skip

[JohnH]

Burnt motor oil... a good way of using this is saturating sawdust with it. The most important part of fluxing is understanding why we do it. That "oatmeal" look which begins to cover the top of the melt over time is oxidized metal. The only way to get that oxidized metal to return to the melt is to remove the oxygen. So we give the crud a carbon rich saturation. The oxygen likes the carbon better than the metal, and migrates to and joins the carbon. The richer the carbonaceous material we use for as a fluxing agent the cleaner our metal gets. Understand this oxidization occurs on the surface and is a direct result of metal contact with the atmosphere. So anything we can do which disrupts that contact reduces the need for fluxing. This is an advantage of bottom pour pots over ladle casting. Each time the ladle enters the melt, it exposes metal to the atmosphere, and oxidation occurs. to some degree we can control the amount of oxidation which occurs by doing things like using ingots to replenish the pot rather than tossing back sprues and boolits. Keeping the melt top up with and ingot or two so that they slip beneath the melt rather than sit atop it half exposed as they melt. Keep the heat of your melt at as lo a tmep as possible. While a lead/tin/antimony alloy will not gravity separate, heat does change how the metals stay in solution, and makes their succeptability to oxidation increase. (The molecules become freer to accept other molecules, because of it's free radical, oxygen readily hooks up...we get oxidation) If ladling, use as large a dipper as you can get away with. The Rowel bottom pour ladles allow for leaving the mold sit on a table rather than holding it and several molds at a time can be filled.

Although I've not tried this out, I've often though of making a circular manifold, getting a flow meter or regulator and running a stream of argon over the pot as I cast to create an oxygen free environment over the melt. If there is no oxygen present, it cannot cause my melt to oxidize. One can rent argon bottles for little cost from a welding supply shop. Things that make you go Hmmmmmmm. But I'm lazy and by reducing the things which aggravate the condition and a bit of burnt motor oil once in a while (I generally don't flux for 4 or 5 casting sessions) I can keep the crud to a level which doesn't cause me trouble.

[cbrick]

Read chapter 4 on fluxing, an outstanding description of how, why & with what to flux.

http://www.lasc.us/Fryxell_Book_textonly2.pdf

[prs]

What do you like to smell? Do you like cedar? It will work, it will smoke a lot. I don't know how much it will flare-up. Look in the cereal cabinet, what is getting too stale, the Shredded Wheat, the Cheerios, the Bran Flakes? How about that 5 year-old carton of Quaker Oats? The smell will be better, it fluxes well, and the flare will be minimal. It will hold moisture, but you simply let it toast a few minutes before dredging-up the depths of the pot. You do have to bring up the lead to make contact to the carbon based material. For reducing oxides, I like beeswax. It works, it smells better than most oils or such. It flares-up pretty sharply! I am talking about fluxing/reducing clean metal in the casting pot. In the rendering pot, I clean and reduce scrap with old deep fat fry oil and dry leaves or saw dust or paper shredder waste.

prs

[fredj338]

I've used just about everything. I prefer wood sawdust. It seems to help keep the alloy blended, doesn't usually catch fire & doesn't attract rust like some casting fluxes. It's also free to anyone that does even a tiny bit of wood working.

[leeggen]

I use the saw dust from cutting cedar trees with the chainsaw. Even after they dry the resin is still in the chips. A cople spoons on the top let it set alittle and push the chips into the lead melt. It will smoke but the neighbor won't complain. After fluxing a couple times I leave a thin layer on top to keep the lead from reacting with the air. This works for me, everyone has their own ideas as to what works. As said above read the chapter on fluxing.
CD

[OnceFired]

I keep it simple. Sawdust for the win. Cheap/free and it works. Never thought about using stale cereal, to be honest. hahahah

[fcvan]

Used ground walnut polishing media. It chars down nicely and sits on the top. My sprues go back in the pot as I cast and just drop through the ash. I tried leaving the flux char on the top after reading about that here. It seems it acts like a vapor barrier which keeps the melt from oxidizing as fast. It also binds well to PC when I re melt PCd boolits that don't pass inspection.

[gray wolf]

Pine shavings do it for me,
get those ingots clean and it makes it a lot easier when it' gets to the casting pot.

[JWFilips]

Oh Boy, You just know what I'm waiting for:popcorn:
The "F" vs "R" Discussion....bound to happen!

[geargnasher]

Read chapter 4 on fluxing, an outstanding description of how, why & with what to flux.

http://www.lasc.us/Fryxell_Book_textonly2.pdf

Not much can be added to that.

Gear

[btroj]

CBrick posted all you need to know. I currently use left over small animal bedding from a long deceased hamster my daughter had. It is aspen and works well.

[Recluse]

I use sawdust for rendering WW and range lead in a cast dutch oven. This stuff is usually really dirty and the sawdust does a very good job of getting the crud out of it. Sometimes it takes a number (2-3) of fluxes to get it clean. I just use paraffin or beeswax in my RCBS pot, because that alloy is already clean. This subject comes up often and sometimes gets controversial. This is what works for me.

Same here.

I do all my smelting of raw/scrap lead outside and I could (generally) care less about how much smoke I generate. I want CLEAN ingots. I also smelt with a melting temperature that is just hot enough to effectively melt the lead. This keeps any inadvertent pieces of zinc from melting and contaminating the pot.

For the outside smelting, I use a decent sized handful of sawdust, generally pine. I flux at least twice, sometimes three times. I'd rather spend the time and make the mess fluxing and cleaning the lead while I'm outside of my reloading shop than inside in the casting pot. The final flux is done with a bit of candle wax. I stir the lead in my dutch oven with a pine stick or paint-stir stick, which also helps with the fluxing.

Like Gray Wolf, once the ingots are in my casting furnace, the only fluxing I'll do is with a bit of candle wax to keep the oxidation to a bare minimum. I put a little bead of wax in, light it with a stick-lighter and then stir it with a metal putty knife. This results in very little smoke.


Read chapter 4 on fluxing, an outstanding description of how, why & with what to flux.

http://www.lasc.us/Fryxell_Book_textonly2.pdf

THIS will give you a very good base knowledge of why fluxing matters and therefore, what to flux with.

:coffee:

[ballistim]

deleted

[edctexas]

For those that like candle wax or parafin, try beeswax once for a comparison. I prefer beeswax to parafin, because it seems to visually be faster and better at the reduction of the oxides. Sawdust works and some of it smells good. It is much better if your sawdust does not have the cuttings of particle board (OSB type stuff). The glue really stinks! And you get more mess to scoop out.

I'll see if I can video the difference between parafin and beeswax.

Ed C

[bangerjim]

Any carbon-based lifeform (or HC) will work, but there are things that seem to be better. I, as many, have found pine sawdust works great in the re-melting process for fluxing grunge out. Other wood dusts work...depends on what you have. I have used pine, cedar, cherry, oak, alder, mahogany, and just about anything under my table saw. In the re-melt pot, sawdust and parafin work wonders. Paraffin is cheap, but really stinks and makes tons of smoke. I flux 3X.

For the casting pot, I prefer beeswax only, as it has has a much higher flash point than paraffin, and smells great! The beeswax REDUCES the Sn back into your casting pot to give you a mirror-bright surface with all the Sn reduced back in where you want it. Just skim off the slight black residue left. Some use wood dust in the casting pot, but if your ingot are 100% pure (you probably made them!) you only need to reduce,not flux. And sawdust can leave garbage behind that somehow can/does make it's way down into your bottom pour spout! At lease it did in mine. I use a pea-sized piece of beeswax while casting and when I add feed ingots to the pot.

There is a lot of info out there. Read up and try different things. You will rapidly find what works best for your needs.

Using man-made woods such as particle board or flake board or pressure-treated wood is NOT recommended. Lots of bad stuff in there you could breathe when it is burning. That eliminates the "free" bags of sawdust from big box stores, as they cut EVERYTHING. If you do not have a saw or a friend that has one, get pet bedding at walmart. You can get beeswax from Randyrat on here or WoodCraft stores or candle stores.

Have fun melting Pb!

bangerjim

[Bzcraig]

Same here.

I do all my smelting of raw/scrap lead outside and I could (generally) care less about how much smoke I generate. I want CLEAN ingots. I also smelt with a melting temperature that is just hot enough to effectively melt the lead. This keeps any inadvertent pieces of zinc from melting and contaminating the pot.

For the outside smelting, I use a decent sized handful of sawdust, generally pine. I flux at least twice, sometimes three times. I'd rather spend the time and make the mess fluxing and cleaning the lead while I'm outside of my reloading shop than inside in the casting pot. The final flux is done with a bit of candle wax. I stir the lead in my dutch oven with a pine stick or paint-stir stick, which also helps with the fluxing.

Like Gray Wolf, once the ingots are in my casting furnace, the only fluxing I'll do is with a bit of candle wax to keep the oxidation to a bare minimum. I put a little bead of wax in, light it with a stick-lighter and then stir it with a metal putty knife. This results in very little smoke.



THIS will give you a very good base knowledge of why fluxing matters and therefore, what to flux with.

:coffee:


This is my exact process as well. You should have all you need now.

[John Boy]

I use a borax based flux that was used by plumbers & electric utility companies that went in their gas burner pots. Friend gave me enough to last 10 life times.
When it hits the melt in the casting pot, I put a match to the smoke. The flux then burns - stir it in and the after removing the dross ... the melt looks like a silver mirror

[trapper9260]

I use ground up corn cobs.The same one I use for my brass cleaning.Had the cobs of the pop corn we grow and then after it get black I just mix in the alloy and it comes out clean.

[osteodoc08]

Red oak, love the smell of it charring. I use beeswax as a reducer. If I have unprocessed beeswax, it can be used for both. Don't add sawdust to your casting pot. I just use beeswax.

Glen Fryxell has covered it and cbrick posted the manuscript for boolit casting. Print it. Read it. Reread it. Read it again.

[Steven Dzupin]

Good old Georgia Pine Rosin.

It works and I like the smell.

I use a inch layer of activated Charcoal on top of the mix

to keep Oxygen away from the melt.

Regards,

Steve

[ukrifleman]

Candle (paraffin) wax for me, I cast outside so smoke is not a problem. I find it does the job just fine.

ukrifleman.

[plainsman456]

I use sawdust/wood shavings.
The brother in law is a shop teacher at the high school and i can get all i want.
I also use the cuttings from the live oak i use for firewood.
It to me smells the beast and works real good.
I have wondered if the different levels of tannin in the wood makes a difference.

I have used wax/paraffin as well but found it does make things a little more messy.

[Mk42gunner]

I use sawdust from whatever the latest tree trimming I have done while smelting outside, I also stir the melt with a DRY stick that I pick up from the yard, (too cheap to buy a piece of wood to stir the lead with).

Trust me, if you hear burbling when you first try to stir the lead, pull that stick out and dry it some more. Burbling and rumbling in a molten pot of lead is the tinsel fairy asking if she can come out to play; YOU DO NOT WANT HER TO VISIT.

Once I put the ingots into the electric pot, I use a small amount of bullet lube to reduce whatever oxides back into the melt. The bullet lube I use is a mystery mix that contains whatever I melted out of the used lubrisizers I have bought and what ever leaks past the H&I dies, works okay for reducing.

Robert

[aharlow]

I use Buck Beaver Flux when i'm melting down my CCOW's to make ingots and it works very well. I have a separate cast iron pot for melting down my dirty COWW's and I use wood paint stir sticks that you can get at Home Depot or Lowe's to mix the flux around with. When i go to cast with the clean ingots i will coat the top of the melt with Pine Sawdust in my Lee bottom pour pot and add as needed to keep the top covered to stop oxidation at the surface of my melt. Works great for me and it smells real nice...lol.
128311

[trixter]

I use sawdust for rendering WW and range lead in a cast dutch oven. This stuff is usually really dirty and the sawdust does a very good job of getting the crud out of it. Sometimes it takes a number (2-3) of fluxes to get it clean. I just use paraffin or beeswax in my RCBS pot, because that alloy is already clean. This subject comes up often and sometimes gets controversial. This is what works for me.

Me too, and it works very well. I have cut up my boolits to be sure they are clean and solid, and they are.

[rexherring]

I use sawdust for my smoker, smells good too, and a little old candle wax.

[JonB_in_Glencoe]

I've only been casting for a month or so but it seems from what I've read that pine sawdust and paraffin seem to be the preferred flux. I've tried both and I'm not overly impressed with the sawdust flux. Can I get some feedback on this subject from some of you who have been casting for long enough to have an intelligent experience. No offense intended.


Read chapter 4 on fluxing, an outstanding description of how, why & with what to flux.

http://www.lasc.us/Fryxell_Book_textonly2.pdf


Not much can be added to that[chapter 4].

Gear

For whatever reason, I find it easier to gleen info from a conversation, than reading from a book, While Glen's book is great info...I learned alot from this thread...plus this thread is entertaining as well ;)

http://castboolits.gunloads.com/showthread.php?253050-fluxing-technique&highlight=

[Toymaker]

Take care using cedar. Approximately 20% of people are allergic to cedar. Getting into the smoke or inhaling it could result in problems. When smelting to cast ingots I use sawdust from the shop. It doesn't seem to make a difference what wood, although pine and related woods seem to work best. When I cast bullets I use candle wax.

[gwpercle]

I use the often and much condemned " Marvelux" . Before becoming an enlightened forum member , I purchased a 4 pound container. I am a tightwad and am not going to just throw it away.
I flux first with the M word, skim whatever comes up. Then do a second fluxing with pencil shavings (from a pencil sharpener), while stirring the shavings, with a wooden stick, I add just a touch of melted beeswax to them and stir everything in really well, stirring and skimming until the melt is clean and free of inclusions.
I place a "cedar smoke"warning sign on the door and the 20% of the population , allergic to it , stay away.
Gary

[ShooterAZ]

I bought some Frankfort Arsenal flux from Midway when I first started casting. This stuff attracts moisture like crazy, and my stirring spoon would pop & sizzle and do a mini tinsel fairy. I do not recommend that product at all!!!

[geargnasher]

For whatever reason, I find it easier to gleen info from a conversation, than reading from a book, While Glen's book is great info...I learned alot from this thread...plus this thread is entertaining as well ;)

http://castboolits.gunloads.com/showthread.php?253050-fluxing-technique&highlight=

Sadist, you are.

:p

Gear

[JWFilips]

A Very Wise man once Wrote.... (& It should be a sticky!) & I quote:

"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"

[jonp]

Oh Boy, You just know what I'm waiting for:popcorn:
The "F" vs "R" Discussion....bound to happen!

You and me both. I remember the last time this came up

[cbrick]

Oh Boy, You just know what I'm waiting for:popcorn:
The "F" vs "R" Discussion....bound to happen!


You and me both. I remember the last time this came up

Not a single garbage BS post in this thread so unless you two are just trying to stir the pot . . . Well, except for these two quoted posts.

Rick

[jonp]

Not a single garbage BS post in this thread so unless you two are just trying to stir the pot . . . Well, except for these two quoted posts.

Rick

Never said anything about "garbage posts" Rick. Calm down. I learned a great deal about flux and reducers in that thread. It just seemed to go on and on and if I remember correctly the Mods ended up closing it down.

[cbrick]

Never said anything about "garbage posts" Rick. Calm down. I learned a great deal about flux and reducers in that thread. It just seemed to go on and on and if I remember correctly the Mods ended up closing it down.

That thread is a sticky.

Rick

[flyingrhino]

Sawdust. Mix it in, light it to burn the smoke. Leave the charred ash. The carbon insulates the lead and prevents oxidation. Assuming using a bottom pour pot.

[jonp]

That thread is a sticky.

Rick
We must be thinking of a different thread. Your an unnecessarily hostile person. Try not to take offense so quickly. Every comment is not a slam against you and you don't have to be right on everything

[JWFilips]

Rick,
I made my first post in Jest...Now I See it may have not been the best thing.......That is why I posted Gear's .."Super Explanation of Flux & reductants " which is wisdom to live by.... No disrespect, Sir
Jim

[cbrick]

We must be thinking of a different thread. Your an unnecessarily hostile person. Try not to take offense so quickly. Every comment is not a slam against you and you don't have to be right on everything

Huh? What are you talking about? That is so amazing and wrong on each count it's actually funny.

Here is the thread in question, a sticky in this forum. Fluxing technique (http://castboolits.gunloads.com/showthread.php?253050-fluxing-technique)

Rick

[cbrick]

Rick,
I made my first post in Jest...Now I See it may have not been the best thing.......That is why I posted Gear's .."Super Explanation of Flux & reductants " which is wisdom to live by.... No disrespect, Sir Jim

Not a problem, I just didn't want to stir up all the BS and start that all over again. I'm not in the slightest hostile, took no offense, didn't think anything here was a slam against me or anyone else and there is nothing about this to be right or wrong about. As simple as that.

Rick

[JWFilips]

Not a problem, I just didn't want to stir up all the BS and start that all over again. I'm not in the slightest hostile, took no offense, didn't think anything here was a slam against me or anyone else and there is nothing about this to be right or wrong about. As simple as that.

Rick

Rick: It's all good! ..Did not want to stir the pot. I'm sure we can always learn something when you guys speak up... I'm aways listening. Thanks for understanding
Jim

[jonp]

Hey, its easier to add someone to your ignore list than I thought. How cool

[cbrick]

128501

[btroj]

So we had a discussion about how long the previous flux thread was drawn out and terse. A discussion that was drawn out and terse.

I think I will go beat my head against a wall.

[geargnasher]

I actually read all this to figure out how, with all the knowledge available, a thread on bullet metal flux ever got to two pages long with my 40 post-per-page view selected. I found two posters who are already on my ignore list. Back to banging my head, but over something much more worthwhile.

Gear

[leftiye]

Crushed charcoal. Leave it on top, cast. End of story.

This was all figured out when? About 2007 IIRC.

[oldlincoln]

Is that real charcoal or BBQ briquettes?

[jonp]

Is that real charcoal or BBQ briquettes?

My question too. I dont remember reading that in the last go around?

[cbrick]

Is that real charcoal or BBQ briquettes?

There was a thread some time ago discussing this. Some of the posts sounded intriguing so I bought a small bag of charcoal for fish tank filters. Before I got a chance to try it & see what/if it would do as flux the thread drifted to several people that had poor success with it and I ended up not trying it. If I remember correctly it was how long it took to burn down to carbon and it's the carbon we want & what does the actual fluxing & reducing. Sawdust burns to carbon very quickly so I stuck with that. Anyone that uses or is going to try charcoal the results would be interesting to a lot of folks I'm sure.

EDIT to add: I just used this search feature Google Search CastBoolits (https://www.google.com/cse/home?cx=001951264366462437169:ggn3vg-bjum) and came up with 10 pages of threads on using charcoal as flux.

Rick

[btroj]

I would think a crushed charcoal briquette would work, I may try that some day.

[geargnasher]

Activated carbon is very adsorbent, which attracts metal oxides, but doesn't reduce squat. You need both. Sawdust does both.

Charcoal briquets are made from only partially burned wood, I don't see why they wouldn't work, but neither do I see any advantage. You want to reduce the easily reduced tin, lead, and antimony first so it isn't adsorbed, the deal with the more difficult to reduce stuff (oxides of zinc, aluminum, calcium, etc) by adsorption. Creating a strong reducing environment by inducing combustion on/near the surface of the alloy does the reduction, the carbon formed as this happens adsorbs the stuff left behind that we don't want so it can be removed.

Gear

[leftiye]

There was a thread some time ago discussing this. Some of the posts sounded intriguing so I bought a small bag of charcoal for fish tank filters. Before I got a chance to try it & see what/if it would do as flux the thread drifted to several people that had poor success with it and I ended up not trying it. If I remember correctly it was how long it took to burn down to carbon and it's the carbon we want & what does the actual fluxing & reducing. Sawdust burns to carbon very quickly so I stuck with that. Anyone that uses or is going to try charcoal the results would be interesting to a lot of folks I'm sure.

EDIT to add: I just used this search feature Google Search CastBoolits (https://www.google.com/cse/home?cx=001951264366462437169:ggn3vg-bjum) and came up with 10 pages of threads on using charcoal as flux. Rick

I use kingsford's. Wood charcoal ("real") never crossed my mind. I don't see the issue with having it "burn down to carbon". It IS carbon, when it burns down it is ash. Ash is only good for keeping the air away from the melt's surface. The whole issue with all of this is to use something chemically more "active" than lead (and antimony and tin) that can wrest the oxygen off of the lead (etc) oxides. Carbon works, and is available. Other thangs will also work, but all of the common reducers contain carbon, and there are a truckload of alternatives. In the present case compare the charcoal to a simple piece of wood used to stir the melt. It fluxes as it stirs. The wood burns due to the heat and takes the oxygen away from the lead. It's the burning down where the fluxing happens. Once burned down the carbon is all turned into CO2.

[ballistim]

My table saw is about 20' away from my smelting set-up, kinda made my decision pretty easy to try it, has worked better for me than anything else. I also use paint sticks or cut myself stirring sticks from scraps when using my table saw, and save all the sawdust for smelting, both pine & hardwood, both work well for me. Stirring with a stick is dual purpose as it cleans the sides & bottom of the pot while adding carbon so its a win-win situation.

[btroj]

Be careful scraping the bottom of the pot with a stick, it is easy to get bits of charred wood stuck in the valve. Been there, done that. I no longer stir with a stick for that reason.

[ballistim]

Be careful scraping the bottom of the pot with a stick, it is easy to get bits of charred wood stuck in the valve. Been there, done that. I no longer stir with a stick for that reason.

So have I! I only do that now in my large smelting pot using a ladle to pour into ingots. I use a layer of sawdust on the surface of my Lee 20# pot when casting to prevent surface oxidation. Good advice on the stirring on the bottom of a bottom pour pot, had to drain a full pot when the valve stuck-no fun indeed!

[wmitty]

Used pecan hulls last couple of casting sessions for fluxing and they worked great.

[jmort]

I am all for thrift, but in my opinion, when you have pine pet bedding or pine kitty litter available for so little, why resort to anything else? I doubt anything will work better for smelting and most everything else will be less effective. If you cannot afford $4.00 to $7.00 for a lifetime supply, I understand.

[geargnasher]

I use kingsford's. Wood charcoal ("real") never crossed my mind. I don't see the issue with having it "burn down to carbon". It IS carbon, when it burns down it is ash. Ash is only good for keeping the air away from the melt's surface. The whole issue with all of this is to use something chemically more "active" than lead (and antimony and tin) that can wrest the oxygen off of the lead (etc) oxides. Carbon works, and is available. Other thangs will also work, but all of the common reducers contain carbon, and there are a truckload of alternatives. In the present case compare the charcoal to a simple piece of wood used to stir the melt. It fluxes as it stirs. The wood burns due to the heat and takes the oxygen away from the lead. It's the burning down where the fluxing happens. Once burned down the carbon is all turned into CO2.

You're talking about reducing, not fluxing. Anything will reduce. Wax, oil, resin, anything that will burn and support the exchange of electrons that shift oxygen atoms from one compound to another. the carbon is to remove UN-reduced oxides of zinc, aluminum, calcium, etc. out of the melt. If they're reduced too and already in suspension, you aren't getting them out again with carbon until they re-oxidize.

Gear

[gwpercle]

I am all for thrift, but in my opinion, when you have pine pet bedding or pine kitty litter available for so little, why resort to anything else? I doubt anything will work better for smelting and most everything else will be less effective. If you cannot afford $4.00 to $7.00 for a lifetime supply, I understand.

Don't get so frugal that you try used kitty litter (as in used by the kitty) that's a smell you wont soon forget. I know there is probably some chemical compound in kitty urine that is good for fluxing but you have to draw the frugality line somewhere.

[prs]

I "think" Kingsford charcoal is compressed of wood product AND bituminous coal. You can buy true wood charcoal of various quality. Vegetative matter like sawdust or nut hulls that have not been pre-charred should perform better as the charring process will pull oxygen from the metallic oxides and the resins in them (that will be lost in the charcoal process) will help bind the impurities.

On the lighter side, try marijuana buds. Wow, man, like, that really -- uh, er, what were we talk'n 'bout?????

Rooster

[geargnasher]

I don't know, but suddenly I'm craving Chee-tos and I don't know why.

Gear

[leebuilder]

Too funny. Used some potato chip/crumbs from the bottom of the bag once. Worked great, took me a while to figure out how fluxing works. I use saw dust and wax scraps, you just have to let it work with stirring and scraping.

[leftiye]

You're talking about reducing, not fluxing. Anything will reduce. Wax, oil, resin, anything that will burn and support the exchange of electrons that shift oxygen atoms from one compound to another. the carbon is to remove UN-reduced oxides of zinc, aluminum, calcium, etc. out of the melt. If they're reduced too and already in suspension, you aren't getting them out again with carbon until they re-oxidize. Gear

Sounds to me like everybody else is talking about reducing too. "If they're reduced too" they aren't oxides any more. True fluxing is simply an aid to skimming (think Marvelux).

[btroj]

Actually, sawdust does both. It chars and burns on a low order producing lots of carbon monoxide. Carbon monoxide is a great reducing agent. Once the wood chars it forms a substance that has lots of capability to adsorb things, things like the stuff we want gone. It holds on to them so when we skim he charred remains of the sawdust we also remove the impurities.

A wax does the reducing but it doesn't adsorb anything. Marvelux just removes everything, no reduction.

With a substance as cheap and universal as sawdust why use anything else? Well, technically I am using pet bedding but same thing essentially.

[cajun shooter]

I have like most tried a bunch of different things to use as a smelting flux. The best by far has been wood shavings, not sawdust, The shavings form a very good carbon pile that will clean anything that I've ever smelted. A member on this forum sold boxes of the stuff until a family problem put him out of business. His shavings were from spruce and they gave off a great smell. Later Fairshake.

[Smoke4320]

Cedar dog bed shaving work well and to me a great smell
a huge bag (many years supply ) will cost $4.00 to $8.00

[jmort]

I would research Cedar smoke before inhaling/enjoying it. My conclusion, Cedar shavings not for me.

[cbrick]

For those that like to use a wood stick to stir and scrape the sides/bottom of the pot here's a word of warning. Your intent is to flux, i.e. clean the alloy however that stick will char under the surface, the charred pieces can/will flake off under the surface and become trapped there. They then go out the bottom spout or get picked up with the ladle and cause inclusions in your bullets. Yes, the charred pieces are much lighter than lead but lead is dense enough to trap and hold them under the surface.

Stirring flux around on the surface of the melt will do a fine job of cleaning the surface of the melt but will do nothing for all the rest of the alloy in the pot. Proper fluxing means using a ladle or spoon to bring the alloy up to the surface and pouring it through the flux and continuing to do so until all of the alloy has been cleaned. Proper fluxing takes time & patience to be done correctly and done well.

Rick

[georgerkahn]

I concur with cbrick (Rick) re methodology; I use a two-step procedure: Step ONE is when I take wheel-weights and "whatever" which is melted over propane in my DCROCKETT pot -- where I vigorously flux with pine sawdust from under my table saw. The results are poured into ingots. Step TWO is when I'm preparing to make boolits, where these ingots -- plus RotoMetal tin and or super-hard is added -- all in an RCBS Pro-Melt, where I again flux with Marvelux and a bit of the red carnuba wax on Gouda cheese. This works for me...
georgerkahn

[JWFilips]

My procedure: Super clean the alloy ingots with flux ( sawdust) a number of times in the smelt. Then only these clean ingots in the bottom pour pot with only the use of a redutant ( bees wax) to get the tin back in... No carbon No Wood stir sticks = perfection in the dropped cast boolits....Very simple Very easy! I learned this from the "Masters" here! Yes and **** can get easily stuck in the bottom of the pot under the weight of the alloy! It does not come to the surface easily!!! Once you know this you will learn never to put **** alloy in your pot nor stir the bottom of a bottom pour pot with a carbonized stick!

I just love the way this site censors stuff! Krap is close to **** There is a lot worse here!

[cbrick]

We concur right up to and right before you mentioned Marvacrap. Anyone tried to bring any of that onto my property much less into my shop there will be a heck of a fight.

Aside from being extremely hydroscopic, aside from how horribly it gunk's up the pot and all tools is the fact that it removes all and any oxidation at the surface. Zero reducing of tin or antimony or anything else, truly nasty stuff. I use sawdust in the smelting pot and in the casting pot. Cleans and reduces. No, sawdust in the casting pot will not cause inclusions in your bullets unless you do something intentional to force it below the surface. Stirring with a wood stick can/will do this.

Rick