This Boolit Alloy

[Wireman134]

Hello, NUB here to the Boolit forum. I just finished casting some 452-252-SWC Lee Boolits. Alloy was a mix of 10lb virgin plumbers lead and about 14 oz. of Tin Babbitt 89%Sn/7.5%Sb/3.5%Cu. This was the first time I mixed in this Babbit I've had, prior to this I used mostly WW for my boolits, mostly quenched in water. I figure the alloy is about 92%PB/7%Sn/.6%Sb/.2%Cu from my calculations. I did a hardness test using the method with the bottle caps with some swagged round balls for a pure lead medium, and my boolit alloy for the unknown. Air cooled I got 12 bhn and quenched she bumped up to about 15 bhn. WW should quench to a higher Bhn would think. This should be a good boolit alloy wright? Also anyone know about a alloyed plumbers lead out there? My last mix with two different plumbers lead ingots , the virgin type and a ingot with "Ant" marked on the bottom. I heard these plumbers a getting away from lead, maybe it had a little tin and antimony alloyed in it. Any thoughts?

[stubshaft]

I've used a similar mix utilizing plumbers lead as a base. AC @ 12BHN is about right but quenched I get around 18BHN. I have never seen plumbers lead with antimony but it could exist. Can't see any reason for them to alloy with it?

[HORNET]

My understanding is that too much tin can inhibit the hardening from the heat treating. 7% sounds like a lot for a heat-treating blend. How long from when you quenched it until hardness testing? It might still be hardening for another couple of weeks. Probably still good for the .45 (unless you're trying for 2100 fps like another poster, sheesh!)

[montana_charlie]

I have never seen plumbers lead with antimony but it could exist.
The antimony (and the copper) came from the babbit.

CM

[Wireman134]

To clarify, the plumbers lead ingot had Ant with some numbers on the bottom. I don't see why. I have yet to test the hardness of that mix. Tested this mix as soon as it solidified a was stable to quench. Took a few min. to become solid. Any one every try testing with this method:

Lead Hardness Test
Here is a simple way to test the Bhn number of unknown lead samples: all you need is a caliper, two bottle caps, a vise, a 5mm diameter (aprox. size) ball bearing, and a known pure sample of lead (Corbin can furnish pure lead of 99.995% Pb with trace silver).
1. Melt enough lead to fill one bottle cap with unknown sample, and the other with known pure lead. Make sure the surface is smooth and flat when the lead hardens and cools.
2. When the lead is cold, put the ball bearing between the two lead surfaces and squeeze this "sandwich" in the vise until the ball is driven partly into both surfaces (just enough to make a fair sized dent, but not past the middle of the ball).
3. Remove the sandwich and measure the two dent diameters. First measure the known pure lead dent and write down this number. Then measure the dent diameter in the unknown lead sample and write it down. Square both numbers (multiply times themselves). Then divide the resulting square of the unknown lead dent diameter into the square of the known pure lead dent diameter. This could be written as (L times L) divided by (X times X) where L is the pure Lead dent diameter, and X is the unknown lead dent diameter.
4. The answer should be a number of 1 or greater. If it is a fraction, or less than 1 in value, you have inverted the two dents and divided the wrong way. In that case, try again. When you get an answer that is 1 or greater, multiply it by 5. This is the actual Brinnell Hardness Number of the unknown sample.
The reason that you will always get a number of 1 or greater is that the ball will always go further into soft material (pure lead) than it will into hard material (any alloy of lead with tin, bismuth, antimony, etc.). Therefore, the diameter of the dent will always be smaller in the unknown sample, if it is harder than pure lead, or the same as the known pure sample, if it is also pure lead. When you divide a smaller number into a larger one, you always get something greater than one for an answer. Brinnell numbers are all greater than one. You must multiply the answer by 5 because this is the adjusting constant for pure lead, which is Bhn 5 hardness.
This method is as accurate as your sample purity and your ability to read the diameter of the dent. A smooth surface is necessary so you can get a clean diameter to measure. A rough surface will throw off the answer because you may not get a true diameter to measure, if one side of the lead surface is higher or wavy. But in general, this is as accurate a method as any that uses tools which cost less than $500. A reading with an accuracy of only Bhn plus or minus 0.5 will be more than sufficient for purposes of swaging. When the Bhn number actually increases from 5 to 10, or doubles, the pressure goes up by a factor of four, or the square of the increase in hardness. A number of 5-6 Bhn is close enough to be called pure for swaging purposes. A number of 10-12 is close enough to be considered about "medium" hardness or suitable for -S dies. A number of 18-20 is hard enough to be considered strictly for the -H type hydraulic dies even if used in the CSP-2 hand press.

[Wireman134]

The plumbers ingots with "Ant" stamped on the bottom were hard to cut and chipped off pieces instead of slicing like the virgin ingots. Also had a granular appearance when separated were chipped. Got my C452-300-RF mold yesterday and mixed in some WW to this alloy for a little more Sb. Approximate mix is 92.5%Pb/5.6%Sn/1.65%Sb/.18%Cu. Boolits water dropped to .452"-453" air cool Bhn 13.5. Should be set with projectiles for a while.

[lwknight]

If that marked "ant" chipped and broke, it probably was around 30 percent antimony.

[kbstenberg]

Wireman a couple of questions please from another newbe.
1 can you use the screwon caps that modern pop botles come with? Will they holdup for the single pour that is needed?
2 without going to the expence an inconvience of having some pure lead on hand all the time just to find the BHN of an Alloy. Can stickie WW be used as the sample for pure lead? Yes i know allmost anything can be alloyed by the manufacturer in making the soft stickie WW.

[Wireman134]

A metal bottle cap (beer bottle or otherwise), that would not give under compression in the vise. Stick on WW are close enough for me to pure lead. I heated the pure lead sample in the bottle cap over the stove in a airgun pellet tin, fluxed in a sliver of wax to level the lead. Cast slug is result of the alloy, still getting harder...

[Wireman134]

If that marked "ant" chipped and broke, it probably was around 30 percent antimony.

Wish I knew it had so much Antimony for sure, would of saved it for alloying instead of a 50/50 mix with pure lead.[smilie=b:[smilie=b:

Chicago plumbers are using a alloy for waste pipe I hear. Got a friend looking for some more.

[JSnover]

Wireman a couple of questions please from another newbe.
1 can you use the screwon caps that modern pop botles come with? Will they holdup for the single pour that is needed?

After WW, the next thing to disappear will be metal bottle caps...:|
I think you could get away with a pair of pipe caps or something else with a similar shape.

[Wireman134]

If that marked "ant" chipped and broke, it probably was around 30 percent antimony.

I just melted down a few of the boolit's that were cast with this alloyed plumbers lead marked with the "ANT" on the bottom mixed 50/50 with virgin lead. Air cooled the alloy tests 15 bhn. I dropped these boolit's in water, so the boolit's are much harder than the test sample. I'm thinking to hard for 1000-1200fps in the Colt and way to hard for the ACP and .380. There probably hovering around 22 bhn wouldn't you think? Maybe I'll cut this alloy with 30% Pb and retest. :rolleyes::rolleyes:

[Wireman134]

The 50/50 mix ("ANT" ingots 50%/Virgin ingots 50%) quenched to 18 Bhn. So I melted down 4 lb. of those boolit's and mixed in 3.5 lb. of Pb to get a 11 Bhn air cooled. Should be good for 16,000 psi. normal Colt and ACP loads. It's hard to get a accurate water quenched reading when samples are poured into bottle caps, got to let the alloy cool to solid before adding to water. I don't want to waste the Sb, I can make more boolit's using the Sb sparingly. I figure I've got about 15 lbs. of these boolit's to cut down the hardness and just enough lead to do it with. Harder isn't always better this time. :mrgreen:

[lwknight]

I found that if there is as much as 6% antimont that there is a definate slushy state when cooling the pot and if the antimony is 30 percent its eternally slushy.
In my 6% mix when the pot is cooling and slushy, I can make a hole in the mix with a spoon and the liquid will fill the hole like digging on the beach.
I'm starting to lean to heat treating and using only 3%(same as clip-on WW) to save money.
I still stick to my guns on 2.5 -3 percent tin to make a really good cast and more importantly your boolits don't oxidize nearly as fast as to get grey lead oxide (poison) on your hands when you touch them.

[Wireman134]

The 50/50 mix ("ANT" ingots 50%/Virgin ingots 50%) quenched to 18 Bhn. So I melted down 4 lb. of those boolit's and mixed in 3.5 lb. of Pb to get a 11 Bhn air cooled. Should be good for 16,000 psi. normal Colt and ACP loads. It's hard to get a accurate water quenched reading when samples are poured into bottle caps, got to let the alloy cool to solid before adding to water. I don't want to waste the Sb, I can make more boolit's using the Sb sparingly. I figure I've got about 15 lbs. of these boolit's to cut down the hardness and just enough lead to do it with. Harder isn't always better this time. :mrgreen:


Still playing with this mix. Added 3 oz. of 89%Sn/7.5%Sb/3.5%Cu Tin Babbitt and assuming the original ingots marked "ANT" had only 12%Sb, I have calculated this thinned out mix has 94.6%Pb/2.5%Sn/2.9%Sb. Sounds like homemade Electrotype.
Bhn air cooled sample tested 8.5 Bhn then initial mid batch sample quenched in water went to 12.8 Bhn, perfect for my use. Then I decided to remelt the two samples to see how uniform the pour was during the casting session. Heated both separately till molten state and quenched just after cooling to a solid. Both samples tested to 17.4 Bhn. Sound about right for that much Sb. Maybe I'll air cool half for lighter loads. Is there a direct relationship between the amount Sb and the hardening of a lead alloy? Maybe air cooled for say a week will give a 12- 13 Bhn then.:holysheep