Lead chart???

[abunaitoo]

Not sure if this sounds reasonable or not, but I have to ask.
Was always told the only stupid question is the one you don't ask.

Is there a chart that would show the pureness of lead by the weight of a measured ball????

My thinking is that you could cast a ball and weigh it to see how pure the lead is.

[largom]

Don't know of any such thing. A lot of variables would come into play such as: Temp. of lead, Temp. of mold, voids in ball, how sprue plate cuts, how tight mold is held, and more.
Also how pure is pure enough?

Larry

[southpaw]

I dont't have a chart but you can use the specific gravity of a piece to find out if it is pure or not. The specific gravity of pure lead is ~11.34. Since the other metals that are comonly mixed with lead are lighter than lead the sg would be less.

To get the sg of a piece of lead do the following:
Weight a piece of your lead. This is your sw (sample weight)
Suspend the piece with a small piece of string (use as small and as thin a piece as possible). This is your dw (dry weight)
Bring a cup of room temp water up under the lead. Keeping it just submerged weight it. This is you ww (wet weight)

To get the sg do the following with the numbers that you now have:
subtract the wet weight from the dry weight. Divide the sample weight by this number

SW / (DW-WW) = SG

If you know that there are only tin and lead pressent you take use this to find the percentage of tin in the mix by taking it a step further.

2049.06 / SG - 180.69 = %TIN

The sg of pure tin is ~7.318
The sg of 50/50 lead tin is ~8.882

Hope this helps.

Jerry Jr.

[abunaitoo]

I'm always amazed at how much knowledge you can get on this fourm.

[techlava]

We have give thanks to Archimedes, who shouted "eureka!" when he solved this problem, while taking a bath over two thousand years ago in Syracuse. Who also had a cone, a sphere, and a cylinder proudly engraved on his grave.