Lead for cupelling
- Thread starter ben2363
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The scrap weights from tire shops, a mix of iron, lead and zinc. The zinc weights are generally painted over.
If your not into sorting just melt both the lead and zinc weights together, the molten zinc floats ontop of the lead and cools faster than the lead and is easy to skim off.
If your not into sorting just melt both the lead and zinc weights together, the molten zinc floats ontop of the lead and cools faster than the lead and is easy to skim off.
I've read of several people using lead from roofing.
I think I first heard of that from Jason in one of his MBMM videos.
I've changed over to using Bismuth. We bought 10 lbs for $20 or $30 and it's going to take me a lot of cupelling to burn through that.
I think I first heard of that from Jason in one of his MBMM videos.
I've changed over to using Bismuth. We bought 10 lbs for $20 or $30 and it's going to take me a lot of cupelling to burn through that.
You can use sinkers of course, but with any lead - if intended to be used for assaying - you need to do blank cupellation. Take say 20-30g of lead and cupell it away without adding anything. If some bead arise from it, you need to substract that from any future assay you will do.
For general cupelling as cleaning method for PMs, sinkers would be just fine, no blank cupellation necessary. Also wheelweights, old lead piping, or even thoroughly cleaned and remelted/skimmed battery electrodes. But I do not recommend those for beginner. Batteries are good source of lead, but you need to know how to eliminate all sulfate salts and PbO2 from it before melting.
Alondro attempts to 'blank' cupel some lead...
Awwww, look at that! A huge gold bead! This lead's contaminated! *throws it away* lol
Ohiogoldfever
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I’ll buy your lead. Twice spot.Alondro attempts to 'blank' cupel some lead...
Awwww, look at that! A huge gold bead! This lead's contaminated! *throws it away* lol
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I get lead net sinkers from local fishermen, old lead tire weights (especially from trucks and heavy tractors) from a friend who is a mechanic, and lead slugs from a local shooting range. They all need to be smelted before cupelling. Zinc, silver, and a little gold usually shake out, more if the lead objects are very old. You could buy lead on EBay or Amazon, but they charge $10 to $20 per half kilo, delivery may be extra, and who knows how pure it is, despite their claims. My cousin Tommy Burke in Coober Pedy approved of my method.
Bunnings Bro you can buy it by the roll or per meter
Despite the low melting point and apparent ease of use, it's really difficult to use bismuth as collector metal instead of lead. Refining will be expensive, and you can lose your PM within intermetallic compounds. Copper or silver can be a much better choice.
