Help--What might this metal be???

Folks-- some time back an old gentleman I know, who used to cast and reload, sold me all his old lead ingots. I've been gradually working through them and melting into smaller ingots that will fit my casting pot. They all look like lead/tin mix and are fairly soft. Today, I melted down one of the ingots, and when it was completely melted, I added a second to the pot. The second one was heavy just like the others and looked and sounded like lead-- but I didn't check hardness. here's the weird part-- when I added that second ingot to the existing melt it literally boiled-- and the whole thing melted in about 3 seconds flat! It was about 3 pounds or so. When I say "Boiled" I mean it looked just like I was boiling water! It didn't spit like if you get a little water in the pot-- and the ingot was bone dry when I put it in-- but it boiled. Anyone ever see this before? what metal that looks like lead and is heavy would do that??

I have been using reclaimed shot and i have seen it boil when added to pot if pot is on the hot side.

Look at a chart that gives the different points on metal temp wise molten, boiling, vapor If you know the pots temp then it should give an idea. I'm wondering about bismuth and or some of the others like what's used in cerosafe. Another is magnesium here a fine chip will ignite and burn with a standard flame. Magnesium has been used in casting shops and cast so it is possible

In the 19th century one practice to "Harden Lead" was to add Mercury.

is it possible that there was any OLD recovered lead?
Mercury boils at 674'F

Even some old shot was so alloyed...

Good thoughts. Don't know how old the recovered alloy was. I do know the pot was not very hot-- I set my pot at the lowest setting I can without letting the bottom pour spout freeze, and I had it at that setting. I've never measured the temperature for that setting.

im getting second hand scared of whatever your boiling there lol

Hick: A hardness testoter is your best friend to determine the the Bhn of any alloy ingot.
I recently finished melting 1240 lbs of muffin tin ingots into 6 lb ingots by different alloys and every 6 pounder is Bhn marked and nicely stacked now ... pure all the way up to mono

Even tin will melt at a few hundred degrees less than lead will. So I would think you might potentially get some boiling from that sort of alloy dropped into a batch of molten lead. Could it have had some wax on it? Or possibly air bubbles or pockets trapped in it?

"Today, I melted down one of the ingots, and when it was completely melted, I added a second to the pot."

The metal didn't boil you placed a cool ingot, flat into molten metal. You trapped air & moisture under the ingot and against the bottom of the pot. The expanding gases look just like boiling. The ingot itself may have been tin/pewter if it melted that fast. Also how hot was the molten metal you dropped it into. I keep my temps down to where the molten just wants to harden onto the ingot some. I bet it was way too hot. Jay

BTW, I've done this exact thing myself & I know the 2nd ingot was pure lead.

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Originally Posted by NyFirefighter357

"Today, I melted down one of the ingots, and when it was completely melted, I added a second to the pot."

The metal didn't boil you placed a cool ingot, flat into molten metal. You trapped air & moisture under the ingot and against the bottom of the pot. The expanding gases look just like boiling. The ingot itself may have been tin/pewter if it melted that fast. Also how hot was the molten metal you dropped it into. I keep my temps down to where the molten just wants to harden onto the ingot some. I bet it was way too hot. Jay

BTW, I've done this exact thing myself & I know the 2nd ingot was pure lead.

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Yes, could have been pure lead-- but it didn't happen like you are suggesting. That is, it didn't go in flat, never reached the bottom of the pot, there were no gas bubbles, and the pot temperature was set at the temperature I normally cast at-- just barely hot enough to keep the bottom pour working. It was about 2 inches thick and 3 inches in diameter and disappeared in seconds. I have checked the smaller ingots made from this melt using the pencil test and they are soft-- so you could be right about the lead. I appreciate the ideas. The thing that startled me was how fast it melted-- I've melted hundreds of pounds of alloy and never had that happen.

I wasn't suggesting the 2nd ingot was pure lead, what I was saying is I have had it happen with pure lead. I think your 2nd ingot was pewter or tin or solder. Tin melts at 450F, solder melts at about 360F depending on alloy.

I have tested (XrF) an unknown sample that was very confusing. It ended up showing Mercury alloyed with the lead. Boiling is scary. Just saying.

Quote:

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Originally Posted by NyFirefighter357

I wasn't suggesting the 2nd ingot was pure lead, what I was saying is I have had it happen with pure lead. I think your 2nd ingot was pewter or tin or solder. Tin melts at 450F, solder melts at about 360F depending on alloy.

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Ahhh OK

Thanks

Since posting I have checked the hardness of the mix, and it seems to be in the 11-12 range (pencil method-- not terribly precise). But, that makes this mix a little harder than the previous ingots-- so that second piece may indeed have been high in tin, as you suggest.

I appropriated some rolls of 60/40 solder from work. I put a bit in my lee pot last night and it melted almost instanstly and bubbled up a little. Maybe it's solder or pure tin. You can always send a sample to that bne bloke.

Quote:

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Originally Posted by Gatch

I appropriated some rolls of 60/40 solder from work. I put a bit in my lee pot last night and it melted almost instanstly and bubbled up a little. Maybe it's solder or pure tin. You can always send a sample to that bne bloke.

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Rosin core? I experienced the same thing when I dropped less than a pound of rosin core 60/40 solder into a pot of molten lead once.