Mike W1
Active Member
First off, partial quotes from another thread.
"fiver
when I first got mine it wouldn't go over 615*
perfect for mixing antimony in the alloy, and fine for ladle casting.
Ian
It isn't really melting, just dissolving into the molten lead. Tin helps it dissolve.
fiver
antimony ore will melt into lead at around 600-625-F.
the trick is to break down the surface tension and patience.
I have done it with marvelux and wax."
Mixed up an alloy last week hoping to get something in the range of Pb 96%, Sb 2.5%,Sn 1% range. I do realize those don't add up 100%!
What I came up with was close. EXCEPT!!! I sent 2 samples off and one had 6.7% Sb and 1.1% Sn. The other was close to my guess.
So I finally did what I should have long ago and checked the melt point of RotoMetals SuperHard which is 745°. Like a knothead I can be I kept my temperature at less than 700° through out the process. Melted the lead, fluxed with stearine, added the SuperHard, and stirred till I could no longer feel any lumps. Fluxed again, and then added the Sn and fluxed again with the Stearine and of course much stirring throughout the process.
I feel that the amount of stirring I did was more than sufficient but am now wondering if keeping the temperature of the melt that low may have been a big blunder.
Could that small sample (bb sized) have been some Sb that really didn't get into the alloy?
Gentleman that ran the test normally presses the samples before he runs the test and he said he felt one sample compress differently than the other. I've tried to do some comparisions with samples off those 2 particular ingots as well as a number of others from that batch. I do remember when I cut the pieces for the original samples that one was hard to cut than the other was.
So after the long way getting here, should I just remelt the whole batch? There's no way those metals had over 6% Sb in them.
Appreciate any thoughts on this!
"fiver
when I first got mine it wouldn't go over 615*
perfect for mixing antimony in the alloy, and fine for ladle casting.
Ian
It isn't really melting, just dissolving into the molten lead. Tin helps it dissolve.
fiver
antimony ore will melt into lead at around 600-625-F.
the trick is to break down the surface tension and patience.
I have done it with marvelux and wax."
Mixed up an alloy last week hoping to get something in the range of Pb 96%, Sb 2.5%,Sn 1% range. I do realize those don't add up 100%!
What I came up with was close. EXCEPT!!! I sent 2 samples off and one had 6.7% Sb and 1.1% Sn. The other was close to my guess.
So I finally did what I should have long ago and checked the melt point of RotoMetals SuperHard which is 745°. Like a knothead I can be I kept my temperature at less than 700° through out the process. Melted the lead, fluxed with stearine, added the SuperHard, and stirred till I could no longer feel any lumps. Fluxed again, and then added the Sn and fluxed again with the Stearine and of course much stirring throughout the process.
I feel that the amount of stirring I did was more than sufficient but am now wondering if keeping the temperature of the melt that low may have been a big blunder.
Could that small sample (bb sized) have been some Sb that really didn't get into the alloy?
Gentleman that ran the test normally presses the samples before he runs the test and he said he felt one sample compress differently than the other. I've tried to do some comparisions with samples off those 2 particular ingots as well as a number of others from that batch. I do remember when I cut the pieces for the original samples that one was hard to cut than the other was.
So after the long way getting here, should I just remelt the whole batch? There's no way those metals had over 6% Sb in them.
Appreciate any thoughts on this!