Fluxing

[saguaro]

How do you k ow when you'vs fluxed enough? I use an old cast iron pot for smelting. Don't know if that makes a difference but I got to wondering when is it enough.

Thanks
Saguaro

[zidave]

I'm also interested in seeing what more experienced casters have to say.

[ColColt]

When casting I put a heaping tablespoon of sawdust on top, wait till it chars and stir gently. I then skim off the dross and put another tablespoon back in and may stir again and repeat the process until little dirt comes to the surface and add another tablespoon to the top to cut down on oxidation.

It you see dirt specks on the bullets just cast, you still have junk in your mix. I just repeat the above.

[Duckiller]

Stir in lots of sawdust with a wood stick. Skim off the dross(black stuff) and stir in more sawdust. keep doing until there is no more black stuff and the lead is nice and shiney, it may have pretty colors in it. I doubt that anyone can tell you exactly how much to flux. Just flux until you think you have all the crud out of your lead. To be able to cast with CLEAN LEAD it is worth it to stir an extra 10 minutes or throw in too much sawdust and have to scoop it out. Think of your final fluxing as part of your meditation becoming one with the silver stream so you can cast pretty boolits.

[geargnasher]

Actually, you can tell how much to flux if using a true flux like sawdust. When "smelting" scrap, I throw in several handfulls (enough to put about a half-inch layer across the pot) and bring up ladlefulls of lead to drizzle through the charring, smoldering sawdust over and over so as much alloy as possible is directly exposed to the sawdust for purification. The sawdust will "absorb" (oversimplification) certain elements we don't want like aluminum, zinc, iron, calcium, and some others) while leaving the tin and antimony bonded with the lead behind. Allow the sawdust to char mostly to ash, and it will likely be like burned-up aluminum foil. Skim it all and do it again. The ash will be finer and less clumpy. When your sawdust chars to a nice, even black color without the burn-foil clumpiness, most of the impurities that it can remove are gone. Sometimes it only takes once, sometimes three or four cycles of drizzling the alloy through until it's ash, skimming clean, and dumping in more sawdust to get the yuck out. Removing the bad contaminants makes a WORLD of difference to the way an alloy will cast.

Gear

[btroj]

Technically Gear the charred wood adsorbs the impurities. It doesn't absorb them.

[felix]

Yeah, think of making a compound as adding (aDsorb) something, like making a polymer by adding radicals. Conversely, making a sponge work (aBsorb) is liking soaking something up and letting it drip out easily later. When you get right down to it, our shooting alloy is done by absorption. True chemical compounding is an adsorbing something to something. ... felix

Here is a stretch: "Ain't" is a compound. "Ya'all" is an alloy. ... felix

[geargnasher]

Technically Gear the charred wood adsorbs the impurities. It doesn't absorb them.

I know, but the six or so people on this forum that know without looking it up what "adsorb" means don't need me to explain it to them, so I used a common, analogous term instead to avoid being called "pedantic".

Gear

[btroj]

Oooohhhhh, pedantic. I like that.

Must be my science education popping up again. Dang chemistry labs. Scary to think I remember the difference after 25 years.

[41 mag fan]

Hmmmm...amazing I was able to absorb some more knowledge in this thread!! [smilie=1:

[slim1836]

I'm still thinking about it.

Slim

[jsizemore]

I know, but the six or so people on this forum that know without looking it up what "adsorb" means don't need me to explain it to them, so I used a common, analogous term instead to avoid being called "pedantic".

Gear

We bow to the benevolence you have bestowed upon us. May we only be worthy.

[Ad Astra]

I learned I'm not using enough sawdust ...


AA

[WHITETAIL]

:redneck:AA, what ever works for you.
Here is what I do.
Smelt the lead.
Scrape all the junk off the top.
Then put a small hand full of saw dust on top.
Then put a piece of wax on top.
Mix it and let it flame up.
Then stir the lead and scrape the sides and bottom
of the pot.
Then remove the ash and junk,
and repeat the dust and wax.
Then pour your ingots.:redneck:

[BubbaJon]

As stated above sawdust and plenty of it. I've found when smelting that if I use the ladle to scoop up and pour back in from a height of 6-8" it helps get that little crud off the bottom and gets the flux mixed in better than if I try to stir it in (since it IS lighter than the lead by far!). Anyway scoop until the top is clear. When casting and using a bottom spout then I add some to the top to keep oxidation down.

[saguaro]

Thanks for the info. I learned I'm not fluxing enough either.

Sagauro