Newbie question on Antimony melting point?

[solman]

I was looking at the Rotometal web site for some antimony. I have some 99% lead and some tin in my stash in the form of 95-5 solder, but no antimony. I thought to smelt up a batch of alloy adding some antimony to the mix to get to a BHN of 12 or so. The Rotometal web site says the melting point for Antimony is 1167 F. I would think that any Sb in the mix would separate out having a much higher melting point. What am I missing here?

[Idz]

The Sb dissolves in the liquid lead. Just like salt disolves in water.

[brewer12345]

If I were loaded up on pure and wanted a harder/more antimonial alloy I would not add pure antimony to the mix. Get some rotometals super hard, which is 30% antimony. A little goes a long way and it will be much easier to get it to melt and incorporate to your alloy.

[Toymaker]

Ah, the alchemy of metallurgy.
Think of the lead as a lattice ball. The pieces of antimony get trapped in the lattice. This changes the properties of the metal. The melting point raises above that of lead, but is significantly lower than the antimony. It is also stronger than lead, and less brittle than antimony.
Now with the lower melting point you can add tin. The antimony and tin bond; this isn't a chemical bond but rather a mechanical bond. This gets trapped in the lattice also. The properties change again. The melting point changes and the metal becomes stronger still.
Now the weird part comes in. As the metal ages, it gets stronger. It also grows!! This is because the "crystals" of lead, antimony and tin are still forming and growing.
Over simplified, but easy to understand. --- to make Lyman #2 alloy I buy Superhard and add pure lead and tin to get the proper ratios.

[jmort]

Lot of threads on this
I believe you can "dissolve" to around 3% at 700 degrees.
I have been wong on this a lot, but do it and have it tested
I would love to see the results

[easilydistrac...]

How bout that. Fellow Newbie here and I was just about to post this same question. I've been reading around and have seen a number of different ways of alloying Sb. Some suggest premelting with a torch before adding to smelt, some recommend a mystery fluxing agent that doesn't appear to be available any longer (antimony man), some say high temps are needed, some chuck it in at regular casting temps and flux like crazy.

From what I can tell, and please correct me if I'm wrong, the high melting point of Sb and its toxicity make it difficult to alloy. Antimony can be alloyed with lead below the melting point of Sb because it, like Idz said, dissolves in suspension. But, the difficulty is getting an evenly mixed alloy. Adding tin and fluxing well helps prevent separation and oxidation. Seems some recommend smelting the Sb and Sn and then mixing that with the lead?

I'd love to hear from those with experience. I'm in the more time than money camp so I've been scrounging a bunch of range lead that will need to be hardened. I know a lot of guys go with a 50/50 WW to scrap mix but a little antimony goes a long way and would give me more usable alloy for less $$.

[brewer12345]

I'd love to hear from those with experience. I'm in the more time than money camp so I've been scrounging a bunch of range lead that will need to be hardened. I know a lot of guys go with a 50/50 WW to scrap mix but a little antimony goes a long way and would give me more usable alloy for less $$.

I think you are exactly right: a little antimony goes a long way. I have successfully been casting lower pressure bullets (38 special, 44 special, etc.) with range lead plus some tin. That is 1.X% antimony and a couple percent tin, give or take. Higher pressure stuff (357 mag, rifle, etc.) I cast from AC COWW plus some tin. This is roughly 3% each of antimony and tin. Most of these boolits are gas checked, but as long as I have the proper size, no issues with either of these alloys.

[LAGS]

I make my alloys from Raw Materials like pure tin that I buy and Pure Antimony added to the lead I get off construction sites.
You have to melt the lead, and add the antimony to the melted lead, Wait a long time like an hour in some cases , plus Flux, but do not Skim off the slag.
The antimony will melt into the mix over time, but at first, it is floating near the top and looks like slag.
When I feel it is melted in as far as it will desolve, I skim up the Dros, and hit the slag or dros with a Mapp Gas torch in a ladle, and pour the melted slag back into the mix.
But DO NOT breath the white smoke that comes off what you are melting with the torch.
The max you can get into your mixture without Professional Smelting equipment is about 23% antimony to lead ratio.
Roto Metals Super Hard is done professionally, that is why they can mix in 30% antimony to lead.
But once the antimony is alloyed with the lead, there is no problem with melting with home equipment for casting even at a 30% ratio.

One thing of note.
When using Raw Materials, it is important that you keep track of the weights of all of your materials.
That way, you can ingot up a bunch of Harder Lead High in Antimony, and save it for adding to other pure lead and tin for the Alloy you want.
As far as the Lead I melt the Antimony into,
If I do not KNOW the specific Alloy Content like Lino or WW, I treat it as pure Lead.
IE, Range scrap, or Unmarked lead ingots that I can not remember where they came from.
But you can ADD pure Antimony to an existing Known alloy alloy to bring up the hardness.

[jsizemore]

You could get some superhard from Rotometals to make life much easier. Antimony on the surface of your melt will look frothy. Rub it with your spoon against the wall of your smelting pot and stir. Keep this up till it's all incorporated. A temp around 800F helps. I hold back some of my Pb till the Sb is incorporated then add the Pb to bring your temp down quickly.

[LAGS]

The Super hard is the way to go for most people.
But when I bring home 300 lb of lead flashing scrap from one job, I would have to add 60 lb of Super Hard to it to get a 4% antimony ratio.
But only have to purchase 12 lb of raw antimony to get the same ratio.
Plus I have the raw antimony to add to known mixes, without adding 70% lead to an alloy like with super hard.
IE
Say I have some smelted COWW, and I want to bump up the hardness a bit for use in my Magnums or rifles.
I just melt down the COWW, and add about 1 to 2% by weight of Antimony to the melted alloy, or I can even add 1% of Tin for cast ability at the same time.
Sure beats adding a scoop or two of Magnum Shot that by weight ,costs a fortune, and you still have an unknown alloy

[trapper9260]

For me I get the Superhard and also the cut tin from the wire like to add to make what I want from the soft lead I have the alloy I am looking for. I say to get yourself a alloy tester to check the BHN also.It make is up to you.I got the Lee one.

[solman]

Lots of good advice thanks all. I guess the Rotometals super hard is the way to go for me. I just have to do the math and check hardness.
Trapper how do you find the Lee tester for ease of use? Can you test ingots with it or just cast bullets?

[Toymaker]

Lyman #2 is 90% lead, 5% tin and 5% antimony with a BHN of 15. You can water drop the bullets and increase that to BHN 17.
Superhard is 70% lead and 30% antimony.
Take 160 oz. of Superhard add 48 oz. of tin and 752 oz. of pure lead and you get 960 oz. of Lyman #2 alloy.