pewter specific grvity

[guncheese]

i know i know, it varies with pewter type
but i smelted up a couple HEAVY for size ornamental pewter (i think they were pewter) pieces from thrift shops
and i like to cast .454 round balls out of it
for easy toss into the pot
i never weighed one before till last night
they came out to 138gr ! that seems pretty "leaddy" to me
http://goo.gl/iCSkzl
how much lead in the pewter does it take to get there?
i didnt pay any attention to the melt temp as it was just a lb or so
even if i did a water volume to weight test it probably wouldnt tell me how "tinny" this stuff is
maybe ill have to carefully melt some to come up with a idea
grrrrrrr...
its not that it really matters, i just want to know!!!

[imashooter2]

Even old ley metal pewter was only about 15% lead. I wouldn't worry about it. Treat it as pure tin.

[jsizemore]

Weight of .454 balls in grains.
Pure Pb weighs 141
COWW weighs 135
Lino weighs 129
Tin weighs 90

[bangerjim]

Weight of .454 balls in grains.
Pure Pb weighs 141
COWW weighs 135
Lino weighs 129
Tin weighs 90

Nailed it! Y'all need to write that info down he just listed for future reference when asking "what is this...is it pewter?" Only way to really know (other than an x-ray scan or lab density analysis) is cast your unknown metal in a know volumetric cavity like the 454 round ball and use it as a reference. You sure cannot do it with ingots, no matter what the shape or size! RB's are better than grooved boolit molds for this.

Thanks!

banger

[imashooter2]

Weight of .454 balls in grains.
Pure Pb weighs 141
COWW weighs 135
Lino weighs 129
Tin weighs 90

That was an education. I wonder what those thrift store trinkets were actually made of? Thanks Jim!

[oldlincoln]

Hey banger, you can do it with any shape of object. Just see how much water it displaces. We need to give a shout out to Archimedes for that one. Eureka!

[jsizemore]

This site did the first 3 and I did the last one the hard way:

http://www.beartoothbullets.com/rescources/calculators/php/roundball.htm

[bangerjim]

Hey banger, you can do it with any shape of object. Just see how much water it displaces. We need to give a shout out to Archimedes for that one. Eureka!

Yes you can, but that induces just another set of errors into the resultant - meniscus reading. That pesky little physical anomaly that makes water cuve up on the sides of a container. And then finding the correct density charts to cross-reference and calculate and multiply and convert to.

I prefer using a know volume round mold to give exact dimensioned pieces to weigh on a scale. I have all the lab equipment to perform density and SG measurements, but rely on plain old gravity to just weigh a known piece of "stuff".

But whatever floats your boat.

banger

[el34]

Yes you can, but that induces just another set of errors into the resultant - meniscus reading.
banger

If you first put water in a liquid measuring thing so that the top of the meniscus just contacts one of the marks, then add the sample and measure the amount the meniscus rose, you could do a pretty good job. And the bigger the sample the better, the smaller the measuring thing's diameter the better.

[guncheese]

wow ! i knew they were "leaddy" but they are COWW leaddy

and yes all hail Archimedes
i was going to do it but i dont quite have anything graduated close enough to measure it

so yup those trinkets should just go right in the pot
as they are not gonna sweeten anything uggggg.....

thanks all!


ohh i know how i could do it
i could tare weight a container and then fill it right to the crest with water and then add the leaddy pewter
letting the crest run off
remove the samples
then weigh the remaining water
then Archimedes will have made me think it through!!

[jsizemore]

Mr. Cheese, My simple specific gravity test.

I use my triple beam with a length of thread tied under the pan. Zero the scale. Tie the piece to the thread and weigh. Record that weight. Take a cup of water and submerge the piece while still on the scale. Make sure there are no bubbles on the piece while submerged. A syringe with some water will knock bubbles off. Get your new weight while submerged. Divide the dry weight by the wet weight. Compare to specific gravity chart. Water used seems to have little influence on the test for our use. You could use a digital reloading scale to weigh, just zero your cup of water. Make sure the sample your weighing doesn't touch the sides or bottom of the water container. Not too complicated.

[guncheese]

to make up for the leaddy trinkets that i smelted and cast into balls
i got a bit of pewter from a local online auction site
19,475 grains of usa and english hallmarked pewter
for $1.71 /lb
http://goo.gl/UtIQ69
already to smelt
http://goo.gl/Zh0889
will cast that into balls and see how leaddy it is
good haul
wish i had one like that every week!

[el34]

Mr. Cheese, My simple specific gravity test.

I use my triple beam with a length of thread tied under the pan. Zero the scale. Tie the piece to the thread and weigh. Record that weight. Take a cup of water and submerge the piece while still on the scale. Make sure there are no bubbles on the piece while submerged. A syringe with some water will knock bubbles off. Get your new weight while submerged. Divide the dry weight by the wet weight. Compare to specific gravity chart. Water used seems to have little influence on the test for our use. You could use a digital reloading scale to weigh, just zero your cup of water. Make sure the sample your weighing doesn't touch the sides or bottom of the water container. Not too complicated.

"EUREKA!" That was Archimedes' reaction to realizing that. For me, it means I did something that worked.

[jsizemore]

to make up for the leaddy trinkets that i smelted and cast into balls
i got a bit of pewter from a local online auction site
19,475 grains of usa and english hallmarked pewter
for $1.71 /lb
http://goo.gl/UtIQ69
already to smelt
http://goo.gl/Zh0889
will cast that into balls and see how leaddy it is
good haul
wish i had one like that every week!

The only thing "iffy" I see in that pile are the candle holders. Smashed in the laundry basket they look fine. Any antimony, copper, or bismuth will affect you findings a little. Not to worry.

[guncheese]

the candle holders had a usa pewter hallmark
and they melted up just fine
here is a resultant round ball
http://goo.gl/vHEtqU

now were talking!
all my other balls go in the pot!!

so the moral of this heavy metal tale is
"watch your tinny trinkets they may be leaddy"

[jsizemore]

Looks like your pewter is about 2/3's the weight of lead.

[guncheese]

Looks like your pewter is about 2/3's the weight of lead.
yup just like you posted!
my balls are .458 so that accounts for the titch more weight

gotta watch your trinkets lest they be COWW

[el34]

The specific gravity of tin- 7.28 and lead- 11.34.
That's a tin/lead ratio of 0.64, right at what jsizemore pointed out.

http://www.goldhog.com/specific_gravity_chart_gold_metals.htmhttp://www.goldhog.com/specific_gravity_chart_gold_metals.htm

[bangerjim]

All those Chicom "trinkets" and other decorative "stuff" can be almost any alloy of softer metals. They were not meant for potable fluids and foods, so there coud be anything in there! Very old pewter had lead in it but that went away years ago. All modern food service stuff should be lead-free. But watch that import carp!

banger