Quote:
Originally Posted by hawnjigs
"sagacious", haven't tried yet, do you flux tire weights before or after removing clips?
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Always before. Be sure to add enough flux to thoroughly wet the clips.
The recovery is better and simpler, since the flux changes the surface tension of the melt and causes the clips to all pop to the top of the melt for easier removal. The lead that had previously wetted some fraction of the clips all beads up and returns to the melt. If you light the smoke, you'll notice that the heat gain helps fluidize the melt, and the crud rapidly separates into a 'less-wetting' compound, and thus retains less lead droplets.
I'll melt down a large pot of tire weights, and when the melt is almost, aaaaalllmost all melted, I'll drop in the flux and light the smoke. The flux, flames, and stirring all removes/separates the gunk, and the added heat instantly melts any unmelted tire clips. This results in a savings of time and expense, plus manages melt temp control-- vs waiting for every last ww to melt and then fluxing. Clips get skimmed, and the quality/'purity' of the melt is assessed, and if good, ingots are poured immediately.
However, if the surface of the melt shows the telltale 'gooseflesh' of tiny particles wetted in the lead melt, I'll flux again to remove them. This process results in 'clean' lead ingots with no entrained foreign matter or particulates in the lead, and that generally doesn't require fluxing later.
Sometimes though, a batch of lead ingots may require fluxing upon later remelting, so one should always re-assess the melt before starting a pouring session. When in doubt: flux the melt. Ingots that are poured at too high a temp are almost guaranteed to require additional fluxing upon melting later. This is another good reason to light the smoke when fluxing scrap lead and pouring ingots-- you want to pour the ingots at just the right temp, and not too hot. Too hot also allows the potential for other deleterious alloying or contaminating elements to dissolve into the lead-- such as zinc tire weights. Lighting the smoke provides a temporary temperature spike that doesn't leave the melt overheated when you're ready to pour ingots-- or ready to start pouring lures.
Be safe, and good luck all!
