2%pewter alloy very hard

[troy_mclure]

i cast a bunch of 10mm boolits using pure lead and 2 % pewter.

i understand that there is not enough antimony for water dropping to harden them up?

i water dropped them to keep hot boolits from rolling around.

these boolits are HARD!

with the ole hammer test it takes a few real good whacks with a 16oz hammer on concrete to dent it.

is this normal? or do i have magical pewter?

[imashooter2]

Maybe your pure lead isn't so pure?

[sagacious]

No magic to it-- if you're normally used to soft lead, they'll be hard all right.

[madsenshooter]

.98[0,0,0,100]+.02[91,7.5,1.5,0]= 1.82%Sn, .15%Sb, .03%Cu, 98%Pb That trace of Cu is a substantial hardener.

[fredj338]

Maybe your pure lead isn't so pure?
Yeah, what is your source of "pure" lead? I add tin to 20-1 & they are harder, but not hard & don't harden if water dropped. So either the pewter has some other metals in it besides tin & lead, which it can, or your lead does.
WikiPewter is a malleable metal alloy, traditionally between 85 and 99 percent tin, with the remainder consisting of copper, antimony, bismuth and lead. Copper and antimony act as hardeners while lead is common in the lower grades of pewter, which have a bluish tint. It has a low melting point, around 170–230 °C, depending on the exact mixture of metals.[1] The word pewter is probably a variation of the word spelter, a colloquial name for zinc.[2]

[troy_mclure]

the lead was from scuba weights, and shot.

[jimmeyjack]

the lead was from scuba weights, and shot.

My scuba weights I cast with WW, so maybe...

[454PB]

And shot can have antimony in it.

[GLL]

Although pewter always contains a high % Sn its chemistry can be all over the place. I find it interesting though that just 2% pewter plus pure lead would be very hard at all !

The old lead-rich pewter I use as a Sn source does not increase hardness very much !

Have you tested the hardness of your pewter before it has been alloyed with the pure lead ? Is your pure lead in the 5-6 range?

Jerry

[runfiverun]

it's the shot.
it contains antimony and arsenic.
the pewter contains tin and antimony.
oh yeah,,,,,,, some extruded soft lead has 3-5% antimony in it too.
so if you used say, water pipe,#7-1/2 shot and pewter from a beer stein.
you could have a 2/5 mix easily enough, by only adding 15% or so shot. really wouldn't matter as the pipe might already be at 5%.
even new stained window came is being made with @ 3% antimony.
then water dropping that will give you 18-20 bhn.

[imashooter2]

the lead was from scuba weights, and shot.

Scuba weights are made of "heavy stuff that melts" and shot has antimony and arsenic in it. You don't have pure lead to start with. That's your answer.

[chboats]

I have had the same kind of results with some scrap lead that had WW, sheet lead from a lead lined tank and range lead from a military pistol range mostly 45 ball. I don't know the percentages but with 1-2 percent tin added to make it cast better it air cools to bhn 10-11.
I water dropped some 255 gr .430 SWC to see what happened. after 2 days they measured 27 to 29 on my LBT hardness tester. Just not sure what all is in the aloy but they got a lot harder than I expected.

Carl

[Fugowii]

Fine pewter is made of Antimony, Tin & Copper (no lead)
The 1958 standard was 92% Tin, 5% Antimony and 3%Copper
This standard would change in a few years to 92% Tin, 6% Antimony and 2% Copper.

[troy_mclure]

i added 2% pewter cause that's the minimum it took to get good fill-out.

whats an easy to use hardness tester?

[fredj338]

the lead was from scuba weights, and shot.

There ya go. As noted, shot has a high antimony & arsenic content, perfect for hardening during water dropping. Dive wts can be anything, including zinc. Try air cooling the next batch if you don't want them so hard. There is no other real advantage to water dropping.

[fecmech]

i added 2% pewter cause that's the minimum it took to get good fill-out.

whats an easy to use hardness tester?

Try this: http://castboolits.gunloads.com/showthread.php?t=75455&highlight=pencils