I zinc i poured some nice boollits

[Oklahoma Rebel]

Today I tried the sawdust thing to remove zinc from what I thought was a contaminated batch. The boollits came out with a crisp mold line (not excessive) and well defined edges. I always drop them from the mold to a bucket of water. anyways they are still harder than I am used to and have a higher ring or sound to them and where the sprue plate cut them it is a little grainy like broken cast steel. could it just be high in tin or antimony, the batch came from ww's, some sinkers, and quite a few jacketed bullet cores, since I skimmed the empty jackets out when I first made this batch. anyways..... thoughts? and im thinking anything I can mold with a propane turkey fryer cannot produce something hard enough to damage my barrel, a new 1895 marlin. appreciate any input, thanks,
The O.K. KIDD

[Mica_Hiebert]

sounds like high antimony, you could add some more tin to make them less brittle also the grainy looking sprue cut could be from cutting the sprue too late or from your alloy temp not being high enough. Im sure a lot of people will disagree with me but I believe that the "dross" you remove with saw dust is mostly your tin! I use a liberal amount of wax and stir it vigorously and that is all I use for fluxing and I get lots of dirt and grim out of my alloy but dont get that strange shiny metal floaty stuff "dross" :shock:

[Oklahoma Rebel]

I didn't get anything but burnt sawdust and a little lead not the dross as we think of it, I also used wax after, so more tin u think,? what about adding pure lead?

[Oklahoma Rebel]

and as far as my assumption that I couldn't cast anything over a propane turkey fryer burner hard enough to damage my barrel ?

[bangerjim]

I doubt you have high Sn or Sb with the stuff you say you melted. Probably hardly any Sn.

From the stuff you say you melted, you will be lucky to have 12Bhn. You are definitely not gonna damage any barrels with that mix. If you want to know the approx hardness, get a set of $15 artist pencils and the chart listed on this forum. Do a search. It is a SWAG but better than guessing from sound or sprue tear!

Sawdust does not really remove Zn. It it only a flux to help clean out all the dirt and crud you get in remelting COWW's. I flux with sawdust and a bit of paraffin 3X with anything that is dirty.

To remove Zn you use sulfur or copper sulfate, which removes your Sn also!

Beeswax in your casting pot reduces the Sn back in to help with cavity fill-out. I use 2% Sn for all my casting.

bangerjim

[turtlezx]

plus 1 on what jim said
if zinc is in ?? in the future do the sulfur treatment