What did i get myself into?

[DragoonDrake]

Hey guys

Since I have started casting, I can not stop from buying heavy metals. I picked up some 20# and followed your advice for finding the specific gravity; it measured 6.176. I can not find anywhere what this is.

Any and all help would be received warmly.

You guys are going to hate me at this rate.

Adam R. Smith

P.S. I still have not had the chance to try your suggestions about the antimony.

[runfiverun]

that is about half of what lead weighs.
try melting some and see what temp it melts at.
and i would bet most of us have some mystery metal around.
i have some that melts, pours,and weighs like lino-type but it aint.

[garandsrus]

Adam,

This is from chapter 3.2 of Joe Brennan's book. The full book or selected chapters can be downloaded by joining the Yahoo CB-Book group, which is free. You can also order a hard copy book or one on CD.

Here's the info from the book:

To make an informed guess as to the composition of that sample alloy we'll use this table that shows the Specific Gravity for some possible alloys of lead, tin and antimony.



Tin % 0 0.5 1 2 3 4 5 6 7 8 9 10 11 12
Antimony %
0 11.34 11.31 11.28 11.22 11.15 11.09 11.03 10.98 10.92 10.86 10.80 10.75 10.69 10.63
1 11.26 11.23 11.20 11.14 11.08 11.02 10.96 10.90 10.84 10.79 10.73 10.67 10.62 10.56
2 11.18 11.15 11.12 11.06 11.00 10.94 10.88 10.83 10.77 10.71 10.66 10.60 10.55 10.49
3 11.10 11.07 11.04 10.98 10.92 10.87 10.81 10.75 10.70 10.64 10.59 10.53 10.48 10.42
4 11.03 11.00 10.97 10.91 10.85 10.79 10.74 10.68 10.63 10.57 10.52 10.46 10.41 10.36
5 10.95 10.92 10.89 10.83 10.78 10.72 10.66 10.61 10.55 10.50 10.45 10.39 10.34 10.29
6 10.87 10.85 10.82 10.76 10.70 10.65 10.59 10.54 10.49 10.43 10.38 10.33 10.27 10.22
7 10.80 10.77 10.74 10.69 10.63 10.58 10.52 10.47 10.42 10.36 10.31 10.26 10.21 10.16
8 10.73 10.70 10.67 10.62 10.56 10.51 10.45 10.40 10.35 10.30 10.25 10.19 10.14 10.09
9 10.66 10.63 10.60 10.55 10.49 10.44 10.39 10.33 10.28 10.23 10.18 10.13 10.08 10.03
10 10.59 10.56 10.53 10.48 10.42 10.37 10.32 10.27 10.22 10.17 10.11 10.07 10.02 9.97
11 10.52 10.49 10.46 10.41 10.36 10.30 10.25 10.20 10.15 10.10 10.05 10.00 9.95 9.91
12 10.45 10.42 10.39 10.34 10.29 10.24 10.19 10.14 10.09 10.04 9.99 9.94 9.89 9.84
13 10.38 10.35 10.33 10.27 10.22 10.17 10.12 10.07 10.02 9.97 9.93 9.88 9.83 9.78
14 10.31 10.28 10.26 10.21 10.16 10.11 10.06 10.01 9.96 9.91 9.86 9.82 9.77 9.72
15 10.24 10.22 10.19 10.14 10.09 10.04 9.99 9.95 9.90 9.85 9.80 9.76 9.71 9.66
16 10.18 10.15 10.13 10.08 10.03 9.98 9.93 9.88 9.84 9.79 9.74 9.70 9.65 9.61
17 10.11 10.09 10.06 10.02 9.97 9.92 9.87 9.82 9.78 9.73 9.68 9.64 9.59 9.55
18 10.05 10.03 10.00 9.95 9.90 9.86 9.81 9.76 9.72 9.67 9.63 9.58 9.54 9.49
19 9.99 9.96 9.94 9.89 9.84 9.80 9.75 9.70 9.66 9.61 9.57 9.52 9.48 9.44
20 9.92 9.90 9.88 9.83 9.78 9.74 9.69 9.64 9.60 9.55 9.51 9.47 9.42 9.38

end of copied book text.

The % tin is along the top (columns) and the % antimony is along the left side (rows). Your sample doesn't fall into any of these specific gravity, so it is either higher in tin than 12% and 20% antimony or your measurement is off somehow.

John

[DragoonDrake]

Anything is possible. It is hard, so it will either make the shot pot with a 50/50 split with lead; or cut in quarters for the sinker mold.

Thanks guys

Adam R. Smith

[Firebird]

Antimony has a density of 6.697, and Tin's is7.31. It is possible that an alloy of the two would be lighter than either, but you might start thinking about getting your metal formally analyzed to find out what is really in it. Or at least take it to a salvage yard who has one of those magic guns that can ID metal alloys.

[Buckshot]

[QUOTE=Firebird;414846]Antimony has a density of 6.697, and Tin's is7.31. It is possible that an alloy of the two would be lighter than either, ...............QUOTE]

..............Sorry, that would be impossible. You're probably thinking of stuff like fixture metal where the ALLOY of the ingredients melt at a lower temp then individually. However a specific gravity could not be less then the lightest ingredient involved.

..............Buckshot