Is Flux important and what can I use?

[Bret4207]

Bret, How do you flux with a stick? Do you use a paint stick for example and stir it in molten lead until it burns up?

More or less, yes. The major fluxing/cleaning is done while smelting down the scrap. For that I use sawdust, anything that will turn to carbon, and something long enough to keep me back as I agitate the melt. Also do this in a purpose bought large dutch oven that holds probably 100+ lbs of lead alloy on a gasoline plumbers furnace that throws a jet of blue flame 4 feet high. Totally serious, it's definitely an outside toy. Once everything is in ingots, then all you should have to contend with is dust and rust/dirt if you are using a ferrous metal pot. I use a very large stainless measuring cup. All I have to do is wait for it to melt and then the DRY stick is used to agitate the melt. I swirl it, rub the bottom and sides of the pot, etc. The stick chars as I go and the char/dirt floats to the top. The ladle goes in and I continue stirring as mo junk comes up. Then I skim the majority of the crap out. I don't try to get every last bit because that's where I think you start removing SN/SB and whatever else is not mixing in good. I will toss the ash, but I don't toss the metal that comes out in the dross. That goes back in the smelting pot for the next go around in case there's a little good stuff in it. If there is char on top of the melt, that's fine. The ladles I use are all built with the nozzle down the side so I'm not pouring the very top layer anyway where the stuff floats.

Seems to work for me.

 

[Snakeoil]

then the DRY stick is used to agitate the melt

DRY cannot be stressed enough for any newbie reading this. Wood has moisture in it naturally and easily absorbs it. Sticking any piece of wood into a pot of molten lead is fraught with danger. Even a cast iron ladle can have moisture trapped it in and so can a stainless spoon that might not be squeaky clean. I did it once because I was not focused on what I was doing. Once is all you need and you NEVER do it again. And this is why you ALWAYS wear safety glasses when casting, melting, whatever. You put them on before you begin to do anything else. And the bigger and goofier looking they are the better. Same goes for leather gloves or some kind of gloves. You hand is the closest thing to the pot and hot lead has no conscience. I've seen guy case without lead and have warned them. They blow me off. Not my problem. I hope they never have to tell me that they should have listened to me.

 

[462]

Not caused by an accident, but through my innate clumsiness, I can attest to the fact that molten lead burns human skin pretty deeply.

In my early casting days, I used a short and thin piece of dead oak branch to stir the wheel weight rendering pot. That is till the time I submerged it and the pot started rumbling and the stick started vibrating. Mt. Shasta is about 400-miles North of me and still active. I don't need a miniature volcano in my back yard.

 

[358156 hp]

I use wood bedding sold for rodents. A bag will last a long time, like decades.

Stir like crazy, bring the nasties to the surface, add a bunch of wood chips, sawdust, whatever. Let it start smoking and ignite. I ignite it to cut down on the smoke. I like to use a spoon to pour lead thru the burning wood and nasties. Keep stirring once it stops burning. I sometimes repeat if I see anything but dirt and ash.

Lots of oxides to reduce back when you add a lot of sprue to the pot.

Is your video still up?

 

[Brad]

This one? Notice the stirring at the end to bring debris to the surface and how I spoon lead thru the wood chips. You want to maximize contact of the oxides with the low order flames, the carbon monoxide is a good reducing agent. The carbon also does a good job of grabbing stuff we don’t want, like calcium and dirt. If I find there is more oxide after doing this I will often add some wax to get more reducing.

 

[Rick]

There is another important reason to not use a wood stick to stir or "flux". As you hold your nice dry stick under the melt it chars (burns), it flakes off and the pieces are held in suspension under the melt. Yes, these little pieces are far lighter than lead but the lead is easily dense enough to hold it in suspension. Kind of self defeating, thinking your fluxing (cleaning) the alloy all the while leaving charred wood in the melt. To each their own, if your happy with that have at it, certainly not for me though.

 

[MW65]

I use doug fir bedding.. comes in large bails, and works great!!! I always leave the ash on top to reduce any oxidation.

 

[Brad]

I would leave the ash if I used bottom pour but with a ladle it just forces debris under the surface and leads to inclusions.

 

[Ian]

Ladling produces a tremendous amount of oxide dross due to the constant exposure of a lot of the alloy's surface area to open air. I find that every so often I need to skim the clumpy oatmeal stuff off the top with a spoon and collect it in a tin can or pie plate for adding back and reducing when I take a break and add more ingots. Ladle casting from a LARGE pot or furnace is really the way to go, working out of a 20-lb furnace like I do where only the top 4-6 pounds are useable is not ideal. This is why I rarely ladle-cast unless I can set up the 150-pound pot and gas burner outside.

 

[Rick]

I must be doing something wrong, I never get the clumpy oatmeal stuff ladle casting. Been using the Magma 40 pound pot for years, before that it was the RCBS 20 pound pot. Just don't have that issue.

 

[JWFilips]

If You are casting with a bottom pour pot: Here is what I do

When you are scraping the bottom of the pot you can feel the gunk! If you toss in a pea size hunk of bee's wax it is amazing that it actually cleans the bottom of the pot also ...the scraping gets smoother and you feel you are contacting steel not gunk...the crap floats to the top! scoop it off!

Just before casting put a good size piece of bee's wax in the pot and light it on fire A solid sealing crust will form on the melt and it will keep oxidation to a minimum! this is they way I do it!
Once casting I add no more lead to the pot until it is almost empty. Then I reduce what is left in the pot with bee's wax, scrape the bottom and sides well and then skim off the oxides... Then I can add more alloy and start over! The melt will be clean ( as long as your ingots are super clean)

my pot scrapers : large one from an old 6 inch stainless ruler with wood handle and also a small hack saw blade scraper

 

[Bret4207]

There is another important reason to not use a wood stick to stir or "flux". As you hold your nice dry stick under the melt it chars (burns), it flakes off and the pieces are held in suspension under the melt. Yes, these little pieces are far lighter than lead but the lead is easily dense enough to hold it in suspension. Kind of self defeating, thinking your fluxing (cleaning) the alloy all the while leaving charred wood in the melt. To each their own, if your happy with that have at it, certainly not for me though.

To each their own. I've not had issues as you describe.

 

[Bret4207]

Ladling produces a tremendous amount of oxide dross due to the constant exposure of a lot of the alloy's surface area to open air. I find that every so often I need to skim the clumpy oatmeal stuff off the top with a spoon and collect it in a tin can or pie plate for adding back and reducing when I take a break and add more ingots. Ladle casting from a LARGE pot or furnace is really the way to go, working out of a 20-lb furnace like I do where only the top 4-6 pounds are useable is not ideal. This is why I rarely ladle-cast unless I can set up the 150-pound pot and gas burner outside.

I don't get much of that stuff. Used to seem to get more with the iron pot, maybe stainless helps?

 

[358156 hp]

I don't get much of that stuff. Used to seem to get more with the iron pot, maybe stainless helps?

I always blamed the ladle itself. Mine can grow quite a beard if I don't keep after it.

 

[Bret4207]

I tend to use a paint stick for stirring/fluxing or something about that size. Although my shop is unheated and I live in the humid northeast, I rarely get much in the way of "sizzle" putting the stick in the melt. But- I tend to leave it where the heat of the melting alloy hit the working end, on the edge of the pot IOW. I think that probably helps.

 

[Bret4207]

I always blamed the ladle itself. Mine can grow quite a beard if I don't keep after it.

Huh. I dunno, when I start getting anything building up I tend to flux and stir and get things mixed back up where I want them.

 

[Brad]

I always blamed the ladle itself. Mine can grow quite a beard if I don't keep after it.

I rub a hunk of wax or bullet lube on the snout and bottom surfaces of the ladle every so often to keep that beard under control.

 

[RicinYakima]

I must be doing something wrong, I never get the clumpy oatmeal stuff ladle casting. Been using the Magma 40 pound pot for years, before that it was the RCBS 20 pound pot. Just don't have that issue.

I don't either since I talked to Ferguson, the Antimony Man, before his death. Lumps are a trimetallic state due to not enough tin and too low of temperature. FWIW

 

[shuz]

For over 50 years I have been fluxing my bottom pour furnace with Marvelux. It just works for me. A small pea sized portion, stir, remove impurities that float to the top, and then place a 1/4 or so layer of clean kitty litter on top of the melt to keep the heat in and the oxygen from the air out.
In all these years my pots have remained clean and my castings free of contaminants.
Some folks swear at Marvelux, I swear by it, and I still remain an authorized disposal outlet for those that have tried it and don't like it.

 

[popper]

leave the ash if I used bottom pour --- Nope, just collects at the spigot.