Lead Ingot problem during melting

[archmaker]

Well I cast up a few boolits using some ingots I had from 20yrs ago.

The thing is I am sure most of my lead back then was all WW and I also had some linotype. (I may have recieved some donated ingots, but do not remember)

Well to get to the point when I fired up my pot I put my ingots in, kept at it till it was almost full and was stirring fine except for 2 ingots. One of them eventually started to melt, but it looked more like the ends were having pockets melted out of it. The other never even looked like it was melting and I just removed them both.

Boolits cast up fine with no problem.

But it does make me wonder what the deal with those two were.

Any ideas?

[SciFiJim]

If they were pure lead, they would melt at a higher temp than WW alloy. The ends melting on the one ingot just got hotter faster than the middle. (think about it, it make sense to melt from the outside in). What temp was your melt when you pulled the ingots?

[runfiverun]

sometimes i get some of the older ingots that are covered with oxides and they don't wanna melt easily they just kinda clump up in the pot for a whils.
try them agan but scratch them all up first.

[archmaker]

I do not know the temp, but the ingots in there had just melted, and I was still stirring so I did not check.

But next time I will try scratching them and seeing what the temp was.

Will also check the hardness.

Thanks guys.

[largom]

Knowing the temperature of your melt would probably answer your question. I try to keep my smelting temp. at 700 deg. or a little less stirring and fluxing regularly. If it does't melt after a reasonable period of time I don't want it in my alloy. I also have ingots that are over 25 yrs. old and due to lack of knowledge I melted anything that would melt without much regard to temp.
I test my unknown ingots for hardness now before I alloy them. Does'nt tell me what they are but gives me an idea of what to expect.
Larry

[JSnover]

Did those odd ingots float? If they sank before they melted they should be ok, shouldn't they?