Problem alloy..."slushy".

[RogerDat]

Pipe organ pipes are usually TIN alloy not lead. At least the ones I have seen. I just missed an entire church organ worth of pipes once. I was most bummed.

As I understand the process sulfur bonds with the zinc contamination and allows pulling it out as dross, with the possible drawback of also pulling tin with it. There might be a sticky on it in this forum I think. So for WW batch that you accidentally melt a bunch of zinc ones in sulfur is supposed to be a way to drive zinc percentage down to where you can cast with it.

[ioon44]

I had a ingot of slushy problem alloy tested with a RxF at a local salvage yard and it showed 88% PB, 5%SB, 3%SN,4%CU. I have tried to melt this into 150 lbs of COWW with Pine bedding and candle wax at 750 deg F and had to skim it off. I have been casting for 50 years and never ran into this problem.

I guess the 4% CU is causing the problem with slush not combining? The RxF didn't show any Zinc at all.

I don't know if I want to try mixing it with a new 140 lb batch of COWW or not, I should have just sold it to the salvage yard but lead goes to the black hole of salvage yard bullet casters will never see it again.

[popper]

Ioon44 - probably need to increase the temp to 850 or so and let it sit for a while. That much Cu does take more heat. Once it is diluted it casts well. I've cast with 2% @ 730, no problem.

[Oklahoma Rebel]

although I believe you with your results,popper, I never go over an estimated .5% copper. I cast with a 4-20 lee (not smelt),and if it isn't quite hot enouch, I can see a "skin" develop on the stream. what do you cast with, a bottom pour? if so what kind? or do you ladle pour.

[ioon44]

Ioon44 - probably need to increase the temp to 850 or so and let it sit for a while. That much Cu does take more heat. Once it is diluted it casts well. I've cast with 2% @ 730, no problem.

When I skimmed this off I had the temp up to 900 deg F and was still slushy. The ingot is only 15 lbs but me being stubborn I will try to beat it into submission by diluting it and adding more Sn to the COWW.

Is adding more Sn going to help it recombine?

[lwknight]

When I skimmed this off I had the temp up to 900 deg F and was still slushy. The ingot is only 15 lbs but me being stubborn I will try to beat it into submission by diluting it and adding more Sn to the COWW.

Is adding more Sn going to help it recombine?

Only 15 pounds is not worth fooling with. I would set it aside to cast fishing weights before wasting more good stuff trying to save it.