Where does the slag come from ...

[Willee]

After fluxing and cleaning the lead mixture, in time, a new layer of crud will form on the top.

Where does all that new crud come from?

Willee

[blikseme300]

The atmosphere. The oxygen in the atmosphere will combine with the hot metal and oxidize. Some use clay-based kitty litter on the melt to create a barrier to slow down this oxidation. I prefer to leave a layer of ash from dry saw dust.

Bliksem

[JeffinNZ]

It is what all those missing socks turn into and rematerialise in the bottom of your lead pot.

[williamwaco]

Spontaneous generation.

Kitty litter works. Fluxing with sawdust and leaving the ash on the top works better ( because it is free )

[geargnasher]

It's oxides of the metals in your alloy. For some reason (not gravity) tin seems to oxidize first on the surface, probably due to it's having the lowest freezing temperature, so if you want a small percentage of tin to remain in your alloy, either keep fluxing or leave a layer of sawdust to char and turn to a protective layer of ash to seal the surface. The protective oxide layer of tin on the molten surface is what helps it make the stream going into your mould more "liquid" and tend to fill out the sharp edges better than alloys with little or no tin. Yes, even the molten, flowing stream of lead is covered with oxide on the surface, any molten metal oxidizes instantly when in contact with air, and lead oxide skin doesn't flow as well as tin oxide does.

Gear

[williamwaco]

It's oxides of the metals in your alloy. For some reason (not gravity) tin seems to oxidize first on the surface, probably due to it's having the lowest freezing temperature, so if you want a small percentage of tin to remain in your alloy, either keep fluxing or leave a layer of sawdust to char and turn to a protective layer of ash to seal the surface. The protective oxide layer of tin on the molten surface is what helps it make the stream going into your mould more "liquid" and tend to fill out the sharp edges better than alloys with little or no tin. Yes, even the molten, flowing stream of lead is covered with oxide on the surface, any molten metal oxidizes instantly when in contact with air, and lead oxide skin doesn't flow as well as tin oxide does.

Gear

WOW, I have wondered for 50 years how tin worked.

I am contantly amazed at what one can learn on this forum.


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[geargnasher]

Me too until I read the Lyman Cast Bullet Handbook #3.

Gear

[williamwaco]

Me too until I read the Lyman Cast Bullet Handbook #3.

Gear


:oops:


Oooops.

I have read everything Lyman ever published and most of it several times.

I sure missed that one.


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