Author Topic: Any way to soften lead (Read 1512 times)

howdy doody · « **on:** July 07, 2003, 07:20:40 PM »

Pards, I was given some lead ingots. I put them in the pot and cast some balls from them. Well, the lead has some tin in it and the balls are too hard to even ram into my C&B cylinders. I cast some bullets from the same batch and they seem to be about right, but I haven't had the chance to shoot them yet to be sure. I was wondering if there is a way to take the lead back to pure form and if the tin would seperate. Thanks.

John Traveler · « **Reply #1 on:** July 07, 2003, 09:03:32 PM »

Howdy, Doody!

Yes, you can separate the alloy into it's lead and tin compoents fairly easily. However, it will not work well with Lino-type alloys.

You melt the alloy and let it SIT undisturbed for say, half an hour. The tin (bluish film or "skin"), being lighter, will float to the upper portion of the pot. You carefully ladle out maybe a third of the pot and set it aside for re-melting.

Continue to melt, WITHOUT FLUXING OR STIRRING! Wait another 20-30 minutes, and ladle out another third and set aside.

Each time you do this, you remove maybe 3-5% of the total tin (it's lighter than Pb or Sb). You can not remove all of the tin, but doing this repeatedly will get much of it out, so that what is left can be used for BP loading.

I've found this method to not work with Linotype alloys because of the higher % of Sn and Sb. Something about the particular % making the crystal latices stay together.

HTH
John

howdy doody · « **Reply #2 on:** July 08, 2003, 04:53:04 AM »

Thanks John Traveler. I will see if I can do that. I really should break down and buy a hardness gauge, so I can tell just what degree of hardness I am working with and desire. Thanks for the tip, pard.

talon · « **Reply #3 on:** July 08, 2003, 04:02:11 PM »

John, will the tin float to the top, or will it float to the outer surface of the lead, that being the top, bottom, and sides of the mass. That's where all my crud goes when I flux. Then it has to be scraped off the bottom and sides.... I doubt if one could scrape tin off the sides without realloying it. Wouldn't it be more practical just to set the hard stuff aside and use it for smokeless bullets, and go get some "pure" lead to make your balls?

John Traveler · « **Reply #4 on:** July 09, 2003, 08:00:18 AM »

Good point, Talon!

True, the easiest wayto get pure lead is to buy it as ingots or lead wire.. but relatively expensive.

This method of salvaging tin/lead mixes came from an old metal shop teacher with years of foundry experience and was a master bullet caster himself.

The gray dusty residue that comes out of lead melt (before fluxing) is the tin component, which oxidizes readily on exposure to air. It clings to the pot walls and floats to the surface when stirred. Fluxing lowers the surface tension (cleans it) and stirring re-constitues the lighter components (tin and antimony) into the melt. He explained that Linotype alloy tends to stay in the Pb/Sn/Sb percentage because of the way the metal crytals pack up when mixed in that alloy.

Anyway, to keep the story short, the scooping business really does work, but it is slow and hot. Easier to buy fresh lead, of course.

talon · « **Reply #5 on:** July 09, 2003, 01:58:05 PM »

I make lead wire from .185 to .360'd, and cast ingots of bnh 5 to 5.5 to make them. It always has been a challange in getting pure scrap lead and you just can't trust anyone's word on what you are getting. Now, I go to a scrap yard and pick thru the lead bin selecting out what I hope to be pure lead, but I'm never sure. This stuff costs 25 cents a pound at current market rates, which isn't bad. Have learned to get stuff that will mark easilly with a knife, has no 'soldiered' joints, does not look like someone else's ingot, or bends easilly. After melting down/fluxing/making an ingot or two, it's tested with an LBT hardness tester. That devise works real good with metals over 6.5 bnh, but its readings between what I KNOW to be pure lead (bnh5) and 6.5 are untrustworthy. Be that as it may, I know it's not much above 5. If I err, my press (electro-hydrolic) will stall out on even the .228"d wire. The .250"d wire flows easilly, thou. This pureness thing has been such a problem that I'll have to try your suggested method of seperating the alloy... any little improvement will be very usefull, as most bullet calibers below .270 use that .228 or .185d wire for core material.

# 566 · « **Reply #6 on:** July 11, 2003, 05:49:05 AM »

Just a thought, place your castings[won't say "your balls] in an oven like you were going to "heat treat" to harden them, intsead of droping them in cold water, leave them in the oven and lower the tempture say 100 deg ever hr. till the oven is OFF then allow then to cool, then check their hardness

Goatlips · « **Reply #7 on:** July 16, 2003, 07:06:49 PM »

Seems to me it makes fine sense to do like John's metal shop teacher said. All the manuals say, when smelting wheelweights anyhow, "Clean the dirt and dross off with your spoon, but the shimmery shiny stuff on top is tin - flux it in, don't throw it away!" Unless, of course, that's yer intention!

Goatlips