Different fluxing dross consistency

[stubbicatt]

I have noticed that if I flux with Marvellux, I get little black specks on top of the melt, which are somewhat difficult to separate from the alloy, but when I flux with a bit of beeswax those little black flecks roll into weightless little black balls which are easy to remove with a spoon without removing alloy.

What are those little black flecks/balls anyways? Just some dirt or something that collects in the alloy? A pea sized ball of wax surely cannot account for the manifold larger quantity of dross that I remove, can it?

Yes I understand that fellas like to flux with wood or sawdust, and I may try that one day. Until then, it is likely wax for me.

[osteodoc08]

Flux with sawdust (carbon) and reduce with wax (puts tin and antimony back in).

Dross has a high % of tin and antimony (which can be reduced back in). Don't just throw it away. I'll save a "dross bucket" from smelting and toss it in the next big smelt I do.

Black specs for me has always been "trash" and gets thrown out. I love beeswax and will keep a layer on top when casting to keep the good stuff from oxidizing.

[bangerjim]

As said.......wax is ONLY a reducer and NOT a flux (which cleans garbage out of your melt).

Most people today use pine (or similar) sawdust as it is easily obtainable and usually free. 3X does it for me. Fluxes all the bad stuff out with the carbon. I add a little hunk of paraffin candle wax the last time. Skim the garbage off. Save it and re-melt later if you are really tight on Pb and alloys. I just throw it away as I have LOTS of alloy.

I ONLY use beeswax in my casting pots. The ingots you previously made SHOULD 110% clean, right?!?!?!? So you do not need any flux there......only need to reduce the Sn (and Sb) back in. A small pea-sized piece of beeswax does if for me. Turns the top nice and shiny almost like magic. Stir it in. Smells good and does not flare up unless your pot is waaaaay too hot.

Try it, you will like it! Save your money used on commercial fluxes and use saw dust or pine pet bedding from WalMart.

banger

[stubbicatt]

So is Marvellux a flux or a reducer?

I still wonder what those weightless little black BB's are. I'm pretty sure my alloy is otherwise clean, it just gets clumpy as I use my dipper/ladle to cast 510 grain bullets, so I add a wee bit of beeswax and stir it up real good. Each time I do that I get a nice smooth surface, and little black weightless bb's to remove. Go maybe 6 to 10 pours and do another dollop of beeswax, repeat of little black bb's.

Oh --do you use pet bedding in your bottom pour pot? Does it clog the works?

[youngmman]

I've tried many types of flux and now use straight Bees Wax. The alloy temp is usually between 700-725 degrees and doesn't usually require additional fluxing between pot fill-ups. I use a Magma 40lb Master Pot.

[osteodoc08]

Don't use anything other than beeswax in your casting pot.

From the sound of it, you have a contaminated pot. I'd drain it all the way down, clean her out and start afresh.

[bangerjim]

So is Marvellux a flux or a reducer?

I still wonder what those weightless little black BB's are. I'm pretty sure my alloy is otherwise clean, it just gets clumpy as I use my dipper/ladle to cast 510 grain bullets, so I add a wee bit of beeswax and stir it up real good. Each time I do that I get a nice smooth surface, and little black weightless bb's to remove. Go maybe 6 to 10 pours and do another dollop of beeswax, repeat of little black bb's.

Oh --do you use pet bedding in your bottom pour pot? Does it clog the works?

I use bottom pours and quite using ANYTHING but beeswax because the carbon bits will find their way down and into the valve! Spent too much time messing with cleaning it out. Don't see how it can sink but it sure does! And just loves getting into that little valve. Avoid sawdust in the casting pot is my rule.

banger

[gwpercle]

I don't know what the little black speck's are , but I also have noticed the different fluxes seem to act differently.
This may be unorthodox, but I flux in this manner, be it smelting or in the melting pot before casting. Start with Marvellux, flux as per directions, Next flux with pencil sharpener wood shavings (cedar ) , because I have access to the stuff. While the shavings are floating on top I add a bit of melted bees wax to the shavings and stir until reduced to a fine ash. then skim of dross and if sometimes do a touch more bees wax, stir again and skim.
It may be over kill but I'm no longer plagued with inclusions in the melt and cast boolits.
I don't use a bottom pour pot, I cast with a Lyman ladle , pressure cast, from open top pot with double cavity moulds.

Gary

[runfiverun]

marvelux is a reducing agent.
you need to cover the whole top of the pot with it to get the oxygen free barrier required to reduce oxides back into the alloy.

marvelux has a couple of bad habits you need to be aware of.
but if used correctly, it does the job of returning oxidized alloy back into the melt and pulls some impurity's [dirt] from the alloy.
I have even used it to get antimonial ore into a lead/tin alloy before.

[RogerDat]

I have two dross buckets. One is from smelting, one for anything I skim while casting. Recently melted both down to recover the metal. Have two ingots, one from each source. I am going to get it gunned. Am dying to see what I skim off in the dross.

Carbon or some sort of black or gray specs are fairly common in my casting pot for ladle casting if I don't keep it cleaned. Wax does drive the tin in as Banger describes and pull the little bits and any remaining "skin" into an easy to skim dross. I guess I always thought the wax caused any metal bound to the specs to be driven off and back into the melt leaving just the debris behind.