How Do You Clean Dirty Wheel Weight Lead?

[detox]

I have about 70lbs of wheel weight lead allready poured into 2.5 lbs ingots. Is it possible to remelt and clean this lead a little better. How do you purify lead?

[Coffeecup]

Melt it down, flux the bejeebers out of it a couple of times, then cast.

[RugerFan]

Melt it down, flux the bejeebers out of it a couple of times, then cast.

Exactly. There is a variety of flux material that people use. Pine sawdust works well for me (Let it turn black before mixing it in).

[Coffeecup]

Yeah, pine works fine. I worry more about the size of the sawdust, so I use a catch-bin (OK, OK, a coffee can) under the outspout on my bandsaw. It is just the right particle size for my preferences. I use about a heaping tablespoon in my RCBS 20# pot.

[detox]

I wonder how Roto Metals flux their big pots for ingot casting. I bet they do not use sawdust.
http://www.rotometals.com/Bullet-Casting-Alloys-s/5.htm

[dragon813gt]

Rotometals is a foundry and uses processes that aren't available to us. I wouldn't worry about what they do.

[**oneshot**]

I use saw dust. Table spoon or so on top of the lead, once it starts to smoke I light it with a stove lighter, sift it around on top until it all turns black. I use a ladle and start a scoop and pour gettinglead and sawdust in the ladle as I pour. Then scrape the pot with a paint stir or metal camping spoon. skim the top crud, scrape with spoon(paint stir), repeat if needed until all the black is gone.
Start casting or pouring new ingots. I do the same when I smelt the ww's down the first time after pulling the clips and dirt off the top, before pouring ingots.

[detox]

The only way I've found any contamination in my mix as many have already advised here is to keep the temperature at approx 600F & scoop out anything that even looks like as RFR said.... lumpy oatmeal.

Removing zinc (lumpy oatmeal). Zinc has a higher melting point than lead 787.2°F (419.5°C)

Lead melting point 621.5°F (327.5°C)

[FLINTNFIRE]

Well I clean wheel weight in the smelting pot , flux and skim , range lead the same way, wet or dry ,I put it all in and start the fire under , no worry about tinsel fairy as it all heats up and then starts to melt , is a dirty mess , but flux and skimming and then it is made into ingots for the casting sessions to come.

[Rex]

Melt it down, throw in some old candle wax and stir after the fire lets me get close enough, then skim.

[James2]

How do you purify lead?

You don't. Wheel weights are an alloy of several metals. Not a problem.
The other metals are hardeners.

When you melt wheel weights, as you know, you have a bunch of junk floating. The thing to do is flux it, stir it, and skim it. Don't skim until you have fluxed as you may remove some of the tin, which tends to float on top. After fluxing, stirring and skimming the surface of the molten lead will be bright and shiny. Not much you can do besides that. Cast bullets or make ingots. Oh, I use deer tallow for flux. Wax or fat works. I have never tried sawdust.

[detox]

James2, Welcome to Cast Boolits forum.

I once recommended parafin or candle wax for fluxing and got bashed. "Candle wax is not a flux...its an old wives tale. Saw dust works lots better as flux" So i now use both saw dust and parafin. Pine sawdust that is..........

Flavor of the month: Pine sawdust

[geargnasher]

Sorry you felt you got "bashed", detox. The simple fact is that, to answer your question, if you want to purify your lead alloy (remove the dissolved junk in there that negatively affects the casting and shooting properties of the alloy), you will need to FLUX. The laws of physics and chemistry dictate that certain things work to accomplish this, and other things conventionally thought to by most people, actually DON'T.

Wax acts as a sacrificial reducant, period. Nothing wrong with that, I use wax to when I need to recycle the scum layer on a pot of metal that has previously been removed of contaminants. When introduced to a pot of molten lead alloy, wax/grease/fat/oil/rosin etc. converts the oxidized metal scum floating on top back to the elemental state in the melt by removing the oxygen, leaving the surface shiny and clean. This saves the tin in particular, because surface oxides seem to be disproportionately rich in tin compared to the melt from which it formed.

However, the waxes and such have limitations to what they do. For example, if you have a lot of aluminum from the aluminum paint found on WW coatings dissolved into the melt, wax won't remove it. Same with calcium, a dangerous contaminant found in higher concentrations today due to the sources of scrap being used by WW manufacturers. Zinc is another bad one, found in trace amounts in WW alloy even if you don't put it in there yourself accidentally when "smelting" your treasure.

Glen Fryxell revolutionized my thinking about cleaning filthy, low-grade scrap for use as boolit metal with the articles he published on-line in several places. Being a Ph, D. chemist with an interest in casting and a strong back ground in heavy-metal poisoning, he understands the relationships between heavy metals and organic compounds. He suggested sawdust as a true flux and has explained in great detail what it does to boolit metal, and what it doesn't do. Essentially the sawdust contains carbohydrates which are essential to removing the specific things we boolit casters consider contaminants while leaving the expensive, precious metals that help us out. Fortuitously, sawdust also makes an excellent sacrificial reducant, so no wax is really needed. If you use sappy pine sawdust, or sawdust and wax, it works even better in some instances, depending on what you're trying to do.

So take my word for it, or read his articles and take his fully-qualified and proven advice, or don't worry about it and keep using wax for the oxides.

Really, the level to which you flux and clean your alloy prior to casting "only matters if it does", as one of the founding members here used to be fond of saying. To much of the sort of work I do, it happens to matter a whole bunch, but not to everything. You will have to decide what you want or need to do.

Gear

PS I don't know what alloying foundries do (probably mix purified metals together and reduce oxides with something organic), but I know that many stages of purification occur when smelting ore, metals are fractionally distilled, fluxed with various substances to capture and remove specific impurities, and the whole process is done in an oxygen-free environment, often recycling the spent flue gas from the furnaces to purge the working area of the metal of air.

[detox]

I wonder how well green pine sawdust will work. I could cut up a green pine log with chainsaw or miter saw and collect chips and sawdust. Would the green wood cause explosion when adding to hot lead? Does it contain too much water?

I think i will remelt and reflux my old inguts in my Pro Melt bottom pour pot. Then repour (using bottom pour) into one pound ingots using my RCBS ingot mould. This should help clean the WW lead some. I have about 70lbs of dirty wheelweight lead to reflux and clean.

[cbrick]

detox, I thought I had given you the link to Glen's book. If not here it is again. Chapter 4 is an eye opener.

You can use green pine but use caution to NOT force it below the surface of the melt, let it char first. Dry is safer though.

From Ingot To Target (http://www.lasc.us/Fryxell_Book_textonly2.pdf)

Rick

[detox]

Thanks Rick, Yes i did speed read it, but I will have to reread

I will do it like this. Stir in pine chips using wooden paint stick scraping sides and avoid touching the bottom. Leave chared chips on top of melt to protect melt. Then pour ingots but stopping when Melt in pot gets 2 inches from bottom. Then add more lead to pot and reflux then pour again.

I think the RCBS ingot mould has four one pound cavities.

[cbrick]

After the chips are chared and turn to carbon use a spoon to bring up alloy into contact with the carbon on top, keep doing this to get as much alloy in contact as you can. Fluxing takes time, it's not just putting sawdust on top, stirring and calling it good. Keep at it, skim off dirty ash and replace with fresh & do all over again.

Rick

[detox]

After the chips are chared and turn to carbon use a spoon to bring up alloy into contact with the carbon on top, keep doing this to get as much alloy in contact as you can. Fluxing takes time, it's not just putting sawdust on top, stirring and calling it good. Keep at it, skim off dirty ash and replace with fresh & do all over again.

Rick

Cool! I will also keep my pot temperature under 700 degrees. Thanks for you help.

[Wal']

As always its refreshing to come here & re-read all the processes others use & the different ways to tweak & improve my smelting methods.

Always open to new ideas, thanks guy's.

[geargnasher]

Rick pointed out something I think is very important, and I always try to mention it when dispensing advice on fluxing when "smelting" dirty scrap: Expose as much of the alloy as possible to the fluxing agent so the flux can do its job.

Personally, I use a ladle to bring up big scoops of alloy from the bottom and drizzle it through the charring sawdust layer on top just like you'd drizzle rasberry sauce over cheescake, nice and slow, thin stream. Do it from right after adding the sawdust and keep doing it over and over again until it's mostly ash, skim, and do it all again.

You may notice a difference in the look and texture of the ash skimmed from the first fluxing compared to subsequent fluxings, usually the skim from the first flux looks like tiny burnt bits of aluminum foil, and the next is a much more fine, powdery ash. Keep repeating fluxing, ladling, and skimming until your sawdust has soaked up all it will soak out of the alloy, and anything left in there will be stuff you WANT, like tin, antimony, silver, gold, bismuth, etc.

Gear

PS If your first skimming looks like I described above, TREAT IT LIKE TOXIC WASTE, because that's what it is. If there's any calcium in that sawdust, I have it on good authority that moisture will react with it and release stibine gas, which can and will kill you in VERY small doses. The scenario would be keeping a bucket of ash skimmings in an enclosed garage or behind the door of your casting shed on a very humid day and walking in there and taking a few deep breaths. I leave my dross in buckets way back on the property for a long time so it can become inert, then dispose of it with my WW clips at the recycler.

[runfiverun]

if you want a good read look up carbourization.
after about 20 minutes you can go to bed and sleep just fine.
it's the process of using carbon in a lead alloy to help all the components that belong there link up properly.

the carbon will also pull gunk up to the top with it while riding a heat current in the alloy.
if you wanna do it right take the time and do it more than once,then reduce the oxides back into the alloy then protect it from happening again.

[SlippShodd]

detox, do you have to use the Pro-Melt for ingotizing, or do you have an alternative "smelting" pot? I only ask because one of the many things I've learned from here was to avoid using my bottom pour pot for the "dirty" jobs. I used to "smelt" in my Pro-Melt and just thought it was the price of admission to have to stop occasionally and strip the thing down to clean all the "klingons" and crud out of it and open the spout back up from the buildup of gak.
Now that I use either a dutch oven or a thrift store stainless pot for the preparation of the alloys, both me and my Pro-Melt are much happier. I still give it a good cleaning at least once a year, but I no longer have to stop in the middle of a casting session and give it an enema. That and the stupid downrod and its paraphenalia get in the way of a good stirring. I still sawdust flux when I'm casting and leave that critical carbon layer on the top of the melt, but I don't purposely introduce any trash to the casting pot.
If you're already on this, I apologize for my impertinence. It was the message I was receiving when I read your posts.

mike

[geargnasher]

if you want a good read look up carbourization.
after about 20 minutes you can go to bed and sleep just fine.
it's the process of using carbon in a lead alloy to help all the components that belong there link up properly.

the carbon will also pull gunk up to the top with it while riding a heat current in the alloy.
if you wanna do it right take the time and do it more than once,then reduce the oxides back into the alloy then protect it from happening again.

That heat current thing is why usually keep a layer of sawdust floating on top of the alloy in my bottom-pour while casting. That and it seals the surface from oxidation even after it turns to ash so the tin content remains the same through the whole session and doesn't end up as scum on top. I don't like to use much tin in antimonial alloys, just a little does what needs done and I darn sure don't want to lose any of it.

Gear

[ddaniel1]

I am using these cedar and pine shavings, they dont seem to be working well or I am using them wrong:
http://www.amazon.com/gp/product/B00061UMP6/ref=wms_ohs_product?ie=UTF8&psc=1
Great info.
Darrell

[mold maker]

I see no reason why they wont work. The flake size is a little big, thus slowing the char process. I use SAW dust, which chars quicker. Ya have to use what ya have at hand, just be patient.
The cedar should smell great as it chars.

[USMC87]

Sawdust works for me and smells good too.

[.5mv^2]

Are you sure you are not over thinking this. I usually stir the pot a bit and use a wooden handled spoon to scoop off the gristle.

Get in and get out. I may shoot 1-2000 rounds a year. I don't want to spend more time than necessary around melting lead alloys. Have tried various soft and hard wood saw dust. Too much smoke and fumes for me.

[cbrick]

Are you sure you are not over thinking this. I usually stir the pot a bit and use a wooden handled spoon to scoop off the gristle.

Get in and get out. I may shoot 1-2000 rounds a year. I don't want to spend more time than necessary around melting lead alloys. Have tried various soft and hard wood saw dust. Too much smoke and fumes for me.

Absolutely yes! We have over thought this therefore we will now change the metallurgy & chemistry of lead alloys & flux so we can stop dealing with smoke & wasting our time. :mrgreen:

Rick

[geargnasher]

Rick, didn't you get the memo? People have been bending the physical properties of lead alloys with their minds for a hundred years to make it such that beeswax is all that they need to make perfect casting metal. My mind is simply too weak to do that, ergo I use sawdust for flux.

Gear

[detox]

I wonder will hard pine lighter (fat wood) sawdust make a good flux? Today i made about 1/2 pound of sawdust from this stuff?

Today i tried a green pine twig to stir my hot lead. I believe my sample was too green for this. I was getting LOTS of splatter so i stopped using the twig. My free Homedepot paint stick works lots better for scrapping sides. The paint stick chars easily, but will last at least 8 fluxings.

My green sawdust (not fat wood) worked verygood by the way, but be careful not to fold it under hot melt too quickly.

[.5mv^2]

Detox, Why were you doing that? Were your projectiles not casting right?

[hickfu]

I would like to thank geargnasher and cbrick for all their advice on this thread. I have been casting for over a year now and I have been wondering about my fluxing not really working all that good. I use what looks like rodent bedding wood chips and a little paraffin wax but always went way too fast according to what I have now read. I have never put any fluxing material into my bottom pour pot as I always thought it would just add more contaminants into my alloy while pouring. I just dropped a little paraffin wax on top and stirred with my paint stick and cleaned off the junk on top.... Now I am thinking that I have been losing tin in the process and will correct this like you have posted Gear with sawdust on top while pouring.

Gear, Just a quick question on alloy if you don't mind answering... I use 75% Clip on WW and 25% pure plumbers lead and then add in 2lbs of Pewter to 100lbs of alloy. Am I adding too much of the pewter to the mix? (I use it for the Tin mostly but the added antimony is a bonus)

Thanks,
Doc

[randyrat]

Leave it to Gear to compare "rasberry sauce over cheesecake" to Fluxing lead. I was well on my way, at least in my mind, to loose a couple pounds of winter coat. Now, I think cheesecake is more important than one notch in my belt. Always a good read, Thanks

[smoked turkey]

I admit that I have taken the fluxing process too casually in the past. I have been doing it basically wrong for more years than I care to admit. I have been one of those get in and get it done with candle wax. My thanks also to those who have contributed to not only this thread but also to the process. I need to read carefully Glens complete work. I did read the part on fluxing and I am anxious to get to my next casting session. I have tried sawdust and a wooden stiring stick in the past without much success, but next time I am going to make it work. My next batch of boolits will be better than the last.

[Ohio Rusty]

I melt the WW's on a steel pan on my coleman stove outside. When they get hot, you can see them start melting. It's starts smoking burning off oil and grease. Once they get melted, there is alot of dirt and the metal clips floating on top. I skim all that off, throw in some sawdust and stit that sawdust down into the metal and stir, stir, stir. They helps take out more dirt and inpurities from the melted lead. I may do that 3 times until everything is clean on top with no dirt floating on the shiny surface. I then pour that moltem metal into ingots and let them cool. If I want to start casting Immediately, I'll put those hot ingots in my Lee melting pot and start casting using the dipper method when they get molten again. I like to clean the lead well and cast them into ingots before putting the lead in my casting pot. It keeps my casting pot cleaner.
Ohio Rusty ><>

[geargnasher]

Doc, Paraffin wax, or any kind of grease/wax/oil like that acts as a sacrificial reducant when added to hot lead will keep your tin/antimony/lead surface oxides 'reverted' into the melt, but only temporarily until it all burns off. If there's sufficient ash left behind to seal the surface off from the atmosphere, just leave it alone after reducing with wax and it won't re-oxidize. The only way you lose tin is by skimming the tin-rich oxide scum off the top of the melt and tossing it without reducing it back into the melt first with wax, sawdust, whatever.

Marvakrap (as I call it) flux is very good flux, it removes impurities from the melt and makes a bombproof oxygen barrier on top if you add enough (per instructions), but one of the things it ALSO removes is tin oxide. So if you don't reduce your oxides before Fluxing with Marvakrap, it sucks up your tin. Now who uses wax to reduce oxides before spooning in their Marvellux? Who knew they needed to in order to prevent tin loss? What you don't know CAN hurt you a little here.

BTW, to put the tin loss paranoia in perspective, it doesn't take much skimming of oxides to affect the tin percentage enough to notice. I did an SG determination on some skimmed oxides that I reduced separately, it was something like 8 IIRC, which is more tin than lead or antimony.

Gear

PS don't submerge green wood in a pot of hot lead unless you want to become very intimate with the Tinsel Faery, and I don't think you do.

[cbrick]

Yes, it will remove not reduce tin. It will also remove any other oxidized metals (antimony) on the surface of the melt so it is a flux but is that what you really want to do?

It is also extremely hydroscopic meaning it sucks up water better than a sponge. That black rock hard gunk on the inside of your pot and on your tools absorbs and holds water, do not rapidly stick your stir spoon back into molten alloy even though it may "look" dry because the tinsel fairy is a certainty.

It collects and builds up on the inside of your casting pot until a stiff wire brush on a drill motor plus a good deal of work is needed to remove it. Do this outside while wearing a quality dust mask, that black powdery dust is some nasty stuff. It is very fine borate glass particles plus arsenic, antimony & lead, do not breath it.

Even wax or oils is a better option than Marvacrap, they won't "flux" but they will reduce not remove your tin and antimony.

Rick

[detox]

Leaving the protective charred sawdust barrier only works with bottom pour casting and not with ladle casting correct? I noticed when using the ladle to cast this disturbs surface and I have to flux more often to put dross back into melt, usually every 15-20 minutes it seems.

I have discovered bottom pouring to be more tricky than ladle pouring. I prefer ladle casting until i get the bottom pour method figured out

[Taylor]

Whatever you do,don't use your wife's scrub brush.I got chastised by her and on here.

[cbrick]

Leaving the protective charred sawdust barrier only works with bottom pour casting and not with ladle casting correct? I noticed when using the ladle to cast this disturbs surface and I have to flux more often to put dross back into melt, usually every 15-20 minutes it seems.

I have discovered bottom pouring to be more tricky than ladle pouring. I prefer ladle casting until i get the bottom pour method figured out

Hhmmm . . . When ladle casting what temp is your pot? You shouldn't need to re-flux nearly that often. I ladle cast through an entire session without a need to re-flux. I put the ladle deep down, sir a bit and bring it up full, keeps the oxidation from forming. Only thing I can think of at the moment is the pot is too hot.

Rick

[detox]

PS don't submerge green wood in a pot of hot lead unless you want to become very intimate with the Tinsel Faery, and I don't think you do.

Yea, little splatters of lead will go everywhere. Even my new paint stick disturbed the Tinsel Faery a little.

[detox]

Hhmmm . . . When ladle casting what temp is your pot? You shouldn't need to re-flux nearly that often. I ladle cast through an entire session without a need to re-flux. I put the ladle deep down, sir a bit and bring it up full, keeps the oxidation from forming. Only thing I can think of at the moment is the pot is too hot.

Rick

I cast between 700-750 using wheel weights. That clean and shiney lead surface will turn dull and drossy fairly quickly. Ladle will also be covered in silvery dross after 15 minutes, but bullets come out very consistant in weight with complete fill.

I am thinking i am not dipping deep enough and not stirring pot enough with ladle.

[hickfu]

I keep my torch right next to my pot so any time I want to stir with either my paint stick or spoon, it get a little attention from the torch first. Thanks for all the great advice on fluxing and keeping sawdust on the top of the pot while pouring, it will now be part of my routine.

Doc

[detox]

Today i tried the pine lighter wood sawdust for flux. As most of you know, pine lighter wood is saturated with pine rosin and will never rot. Excellent stuff for starting fires, BUT not for fluxing. It leaves behind lots of charred pine rosin residue buildup on pot and spoon.

Regular pine board sawdust leaves behind way less residue buildup.

Today i practiced using bottom pour pot while casting small 180 grain 308 bullets. I still get more rejects using bottom pour vs. ladle.