COWW composition

[silverjay]

First time smelting coww so I had an ingot tested to see the composition. Here is what I found:

Pb 91.97
Al 2.21
Sb 1.81
Si 1.29
Zn 0.91
Ti 0.80
Sn 0.74
P 0.28

Does that seem right? I think the Ti came from paint on some weights. It filled the mold well and made decent boolits for my first time casting.

[williamwaco]

WOW.

That sounds like some serious recycling been going on.


.

[runfiverun]

change the P to As.
the aluminum seems a bit high.
and the Si would probably be Bi. [as normally read]
i'm not seeing any Cu, Indium, or calcium which is normal to see.

[silverjay]

What you see is what the X-ray refraction read. Only thing in the pot was sorted coww's.

[SciFiJim]

With silicon (Si) so high, was there sand in your ingot. It seems kind of high.

Not disputing the numbers that you got, it just seems odd from what has been found before.

[silverjay]

Not sure how, I washed the coww's with mineral spirits and cleaned the oil out of the pot with rubbing alcohol. Doesn't seem like a right mix to me, but not sure how it got there/I messed it up.

[44man]

The very reason why we never all get the same results. It is those stinking re-cycle boobs. Nothing matters for a WW as long as it meets balance weight.
Zinc stick on's get melted in with everything else. I think those things are the ruination of our beloved WW's.

[jimb16]

Smelt your lead at a lower temp and you won't have the Zn melting. You can scoop it out with the crud.

[geargnasher]

I think 44man was referring to the zinkers that find their way into the recycled scrap metals that the WW makers buy to make new weights.

Aluminum is probably from the aluminum flakes used in the epoxy coating of some of the aluminum-wheel weights to make them purty. Sawdust fluxing cures that, along with calcium and iron contamination. Not sure if sawdust will remove silica, that might require a different sort of flux. Of couse you could just leave it in there and call your boolits "hypereutectic" like the silica-aluminum racing pistons.:D

If it casts good boolits, go with it. If it won't cast well due to suspected contaminants, flux it with sawdust.

Gear

[silverjay]

Thanks, I fluxed it twice with pine shavings but maybe that wasn't enough.

[GLL]

silverjay:

Can you provide some information about the X-ray "refraction" instrument used in your analysis?

Jerry

[geargnasher]

Thanks, I fluxed it twice with pine shavings but maybe that wasn't enough.

The only way to get at the dissolved (alloyed) contaminating metals like aluminum is to expose it all to the flux. I like to put a thick layer of sawdust/shavings on top of the pot and ladle the alloy up and drizzle through the sawdust like percolating coffee, this ensures as much of the alloy actually gets to touch the flux as possible. The flux can't work on what it can't get to. Stirring a lot helps, too due to the natural heat currents in the pot, and will cycle alloy by the stuff on the surface if you keep the surface layer of flux in a state of constant disturbance. You may have actually pulled out the calcium with the fluxing, or the scanner might not have tested for it in the first place.

Think of the sawdust/wood shavings as an absorbent filter, like activated carbon in an aquarium filter absorbing dissolved ammonia from the water as the water passes through it. Not quite the same reaction with sawdust and calcium/aluminum/etc., but the physical analogy applies.

Gear

[silverjay]

silverjay:

Can you provide some information about the X-ray "refraction" instrument used in your analysis?

Jerry

It is actually an X-ray fluorescence gun made by Niton. Takes 17 seconds to scan a piece of metal that must be larger than a quarter.

[silverjay]

The only way to get at the dissolved (alloyed) contaminating metals like aluminum is to expose it all to the flux. I like to put a thick layer of sawdust/shavings on top of the pot and ladle the alloy up and drizzle through the sawdust like percolating coffee, this ensures as much of the alloy actually gets to touch the flux as possible. The flux can't work on what it can't get to. Stirring a lot helps, too due to the natural heat currents in the pot, and will cycle alloy by the stuff on the surface if you keep the surface layer of flux in a state of constant disturbance. You may have actually pulled out the calcium with the fluxing, or the scanner might not have tested for it in the first place.

Think of the sawdust/wood shavings as an absorbent filter, like activated carbon in an aquarium filter absorbing dissolved ammonia from the water as the water passes through it. Not quite the same reaction with sawdust and calcium/aluminum/etc., but the physical analogy applies.

Gear

Thanks, sounds like I did not mix enough to get full exposure. Will do more next time. Thanks.

[JeffinNZ]

Does it cast and shoot OK? If so, then you are over thinking it.

[trixter]

Wow that is cool.