i've been casting ingots for a couple days now, but today i moved up to a larger setup to melt more lead at once. im now using a 73000 btu cooker set to medium and a metal 5 gallon pail. i loaded about 35# of clip on WW and as soon as it went molten i skimmed off the clips and steel/zinc weights, then a couple minuites later once the temp came up a bit higher i dropped in a piece of wax and stirred/scraped.
but when i skimmed off the dross, to my surprise i pulled out a steel clip... i dont know how i missed it, and have no way of knowing if it was from a lead weight or a melted zinc one, but when i poured the muffin molds the ingots came out with a significant ammount of bubbles on the base of the ingots.
the mold has been used for several days without this issue, so does this sound like zinc contamination or something of lesser concern? due to me using a larger setup i don't know if it could be related to temperature or what. i was also water quenching the molds on a cookie sheet to allow for a quicker release from the mold if that would have any affect.
any info/opinions would be greatly appreciated.
Mike