hardening up soft lead

[bigjake]

Hi all,
Roughly How much of rotometals "super hard" (30% antimony- 70%lead) would it take to make 100 lbs. of pure softie lead about the hardness that of WW's?
thanks in advance.

[Fire_stick]

I found this page the other night. Your answer is probably here.

http://www.lasc.us/SuperHard.htm

[lwknight]

10 pounds exactly to make 100 pounds of 3% antimony.
Its simple math.

[bumpo628]

According to my alloy calculator, if you add the following three ingredients:
Pure Lead - 92 lbs
Super Hard Alloy - 7 lbs
50/50 Solder - 1 lbs

You get an alloy similar to WW lead:
Tin % = 0.50%
Antimony % = 2.10%
Lead % = 97.4%
Weight = 100.0 lbs
Est. Hardness = 10.7

You can download a copy of my calculator here:
http://castboolits.gunloads.com/showthread.php?t=105952&highlight=lead+alloy+calculators
Be sure to get the 2/14/11 version.

[nanuk]

10 pounds exactly to make 100 pounds of 3% antimony.
Its simple math.


lwknight.... Math ain't that simple. Using yours, you'd end up with 0.0272727 repeating percentage of antimony.

I can't come up with the formula off the top of my head, but you would need to add between 11 and 12 lbs of your 30/70 to 100lbs lead to make a 3% antimony alloy.

just by eliimination, 11.1 lbs gets you 2.997929%. using math. and that is assuming exactly 100lbs lead

[bumpo628]

10 lbs of Superhard Lead and 90 lbs of Pure Lead will give you 3% Antimony.
However, that is harder than WW and there is no Tin so there will be poor mold fillout.

[lwknight]

Simplification :
If 10% of 10 pounds is 1 pound then 30% of 10 pounds is 3 pounds.
10 pounds of 30% antimony has 3 pounds of antimony and 7 pounds of lead.
Add that to 90 pounds of lead and you get 97 pounds of lead and 3 pounds of antimony.
Total of 100 pounds that is 3% antimony.
Substitute 2 pounds of tin for 2 pounds of lead and you still have 3% antimony and 2% tin and 95% lead.

That was the simple explanation. My actual calculations are a bit more complex.
Also if you think of everything in 100 pound quantities , it makes the percentages easier to figure.

The easiest way to check your math is just to ask yourself " does the answer make sense?".