Sawdust?

[Leon Garfield]

After reading on this site about sawdust in the lead for flux I have been using it. My question is how long do you leave it in? Till it stops smoking, till it turns black, I try stiring it in but that doesn't work very well. Anyway please give me your advise. Thanks

[country gent]

Put the sawdust on the pot let sit a few mins to dry fully it will start to burn char. Stir pot scrapping sides and bottom of pot and working alloy up thru the charred sawdust. Continue this until surface is bright and shiny. With a bottom pour pot you can leave it on the surface to reduce oxidation rates. If ladle casting from pot then you want to clean it off. Since sawdust can hold moisture letting it set and start to char is important.

[Leon Garfield]

I am using a ladle to mold. Bullets look great. Thank you very much for info.

[cdngunner]

You are after the carbon. Most impurities will bond with the carbon.

Let it char, take a slotted spoon and push it down and through the lead.

Scrape, scrape, scrape...

Skim, skim, skim

Use wax if you start seeing yellow

[runfiverun]

you want the black carbon from the saw dust.
burn it.
the process is called carborization.

you need an oxygen free barrier to return the oxides back into the alloy
since dry ice is difficult at best to work with around lead, I recommend the use of fire.

[psweigle]

You are after the carbon. Most impurities will bond with the carbon.

Let it char, take a slotted spoon and push it down and through the lead.

Scrape, scrape, scrape...

Skim, skim, skim

Use wax if you start seeing yellow I second it. I use crayons for wax fluxing.

[Leon Garfield]

So i have seen a yellow bluish color at sometimes in the oxydization on the top. I was unsure what it was just figured stuff coming out of lead. So when i see this i need to use wax to flux? If i scrap the haze off lead is very shinny underneath.

[cbrick]

What your seeing is tin oxidation, the sawdust will return this to the melt, don't scrape it off. Using both sawdust and wax hurts nothing, a bit redundant since your already using sawdust.

Welcome to CastBoolits Leon, :mrgreen:

Rick

[bangerjim]

Oh goodie! Technicolor lead!!!!! [smilie=w:

Wood dust and wax work well. I use dust in melting pot and beeswax ONLY in my casting pot. As said above, some leave the carbon on the surface. I use bottom pour exclusively but have tried ladle casting and tended to get dust in my pour even with a side/bottom ladle.

Whatever you use, you need to keep those good elements in there! I even use dried leaves!

banger

[mdi]

Already been beat to death here; http://castboolits.gunloads.com/showthread.php?253050-fluxing-technique

[runfiverun]

beat to death several times, but if it ain't clear in the askers head then it ain't finished...

if you are seeing blue and gold on top of your alloy it's time to turn down the heat, your at 750/800-f.

[Leon Garfield]

Thanks everyone for all the helpful information. I did search this before i posted but that doesnt always get you what you need. Thanks