Do I need to Flux pure lead?

[John C]

I bought some pure lead that I'm going to cast into Minie balls for a rifled musket.

Do I need to flux the lead? As I understand it, fluxing is to remix the other components of the alloy (tin or antimony) back into the mix, since they part when melted.

If it's pure lead, will I need to flux? Are there other reasons to flux?

Thanks,

-John C

 

[Lloyd Smale]

main reason to flux is to clean contaminents out of you lead and pot. Alot of very knowlegable casters will tell you that tin and antiomony cant seperate once mixed and its a waste of time to flux to do that. I dont flux very much any more just when alloying and maybe once when i start the casting session.

 

[HSMITH]

ALWAYS flux your melt. It certainly won't hurt anything, and it will clean the melt if there are contaminants in it.

 

[John C]

Thanks, guys.

I think I will flux, even if just to be safe. I think I can bum some marvellux off a buddy of mine.

-John C

 

[HSMITH]

Plain old wax works fine too. I get the little tea light candles from the dollar store a lot, you get a bag with about 20 of them in it for a buck, and a quarter of one will flux a 25 pound pot a couple times.

 

[happy old sailor]

i flux, no matter the material. i just feel better about it. dont hurt

 

[Steve Smith]

If you have an Applebees or Red Robin nearby you will see that they have a huge mound of crayons near the door for kids. Grab yourself a bundle or two (three crayons to the bundle) on your way out.

Break a crayon in half and toss it in, paper and all. The paper will catch fire and burn off bad gasses, and the wax will clean your pot.

 

[Poodleshooter]

For pure lead, I just stir and scrape the sides of the pot to get contaminants up to the surface for skimming.
Since skimming might reduce the content of alloyed lead, I just skim briefly for the wheelweight clips and then flux (though my wheelweights are so greasy, they hardly need any added flux to start fires in my pot).

 

[klw]

Fluxing

Fluxing may or may not bring dirt to the top of a furnace load. Personally I think that it does. With pure metals, like lead, or eutectic alloys, like linotype, fluxing will NOT mix the metals back together because they chemically can not separate.

Does fluxing do any harm? Yes it can and you can prove it. Take a single cavity mould that you know cast bullets of uniform weight. Cast with it for a couple of hours keeping the bullets lined up in their as cast order. Flux say every half hour. Then weight all the bullets in their as cast order and note which ones are visually acceptable and which ones aren't. Plot the results.

What you'll find is that bullet weights drop after the fluxing. Colder mould I suppose. Also there will be a decrease in the visual acceptance rate immediately after the fluxing. If you flux a lot, these two effects can be significant.

I flux once every few months but only before or after a casting session. Never during it.

 

[cracked butt]

I use a large pinch of sawdust for fluxing, I'm doing construction on my house, so I now have a lifetime supply of sawdust to burn I'm a little skittish about Marvellux now, as I had a small lead explosion while fluxing with the stuff- I fluxed one pot, and left a spoon with a bit left on it sit out, later when I refilled the pot with ingots, I fluxed again, and the lead spit all over the place when I immersed the spoon. I'm guessing that the marvellux might be hydroscopic and picked up some moisture while sitting on the spoon.

From what I've read, though I'm no expert, is that if you use something like wax or Marvellux, it forms a thin layer on top of the melt to seal out the air to keep the tin from oxidizing, though this would only be useful for bottom pour casting I guess.

 

[Lloyd Smale]

Addded to that i quit using marvelluxe because it leaves a very hard crust on the pot that is about impossible to remove other then chipping it out. I use wax or bullet lube to flux now. Like was said i flux but sparingly. I truely believe that you can overflux and its worse then not fluxing at all.