Melting antimony

[papa bear]

Any thing new on melting antimony in lead? I read the stuff from last year and wondered if anyone had any new incites.

[georgewxxx]

I'm not sure what you read, but good luck trying to melt antimony. The melting point is over 1100 degrees. When in your lead mix, it is more like a powder in suspension....geo

[wills]

Check with The Antimony Man.

[imashooter2]

Back in the day, I acquired a 5 pound lump of antimony from a local metals supplier. I built a charcoal blast furnace from firebrick and a shop vac to achieve the over 1,167 degrees required to melt it. I placed the antimony and 5 pounds of lead in a heavy cast iron crucible and put a thick layer of powdered charcoal over the surface of the raw material. The end result was a 50/50 mix with lead that would then melt at normal casting pot temperatures. It was an enormous PITA. I'd never do it again. Type metal is too cheap and available.

[papa bear]

I have been in touch with Mr Ferguson (the antimony man) and he has some ideas but he feels it is not really worth messing with. I just have a bunch of scrap lead and wanted to convert it to something more useful.

[Dale53]

When I was just a young teen ager, I got some antimony. I was successful at melting it (with the help of gas range and a torch). It worked as advertised but once was enough.

Since then, I have used lead, tin, WW's, and linotype. Much, much easier to use.

If I came onto a large supply, I would do as "imashooter2" but would do a LARGE lot mixed with lead to then use as a "sweetener".

I have no intentions of doing this, but one never knows what the future will bring. I try to keep an open mind...

Dale53
Dale53

[KYCaster]

There is absolutly no reason to melt Antimony to get it to alloy with Lead. It will disolve at normal casting temps.

The process is simple and has been described here at least four times. A search should turn up the info.

Jerry

[Ricochet]

I bought some "Plus Metal" a few years back when Wiljen did the group buy on it. That's the stuff the typesetters used to refresh their tired linotype, I think. It's a pretty easy way to harden up the pure lead.

[rob45]

The process is done at normal lead melting temperatures. Commercial/industrial operations have a lid with a motorized stir paddle, and the alloying process is best served by having an inert atmosphere above the melt (such as an argon shield). Lots of different ideas, especially concerning specialized fluxes, have been presented to make the process easier. The truth is- antimony alloys with other elements easier than it does with lead.

Mere speculation suggests that alloying a tin/lead alloy with antimony will be easier to accomplish than alloying only pure lead and antimony, due to the formation of the intermetallic compound SbSn. It would take a metallurgist to explain why, but such speculation is based upon my experience. I have found it considerably easier to add pure antimony to something that already has tin or antimony in it. In my experience, it is harder to do if working only with pure lead and antimony, but it's not impossible- it just takes more patience.

The best way to do this at home is to have an insulating layer on top of the melt. Crushed charcoal is good, kitty litter (bentonite clay) is also very good for this. The purpose of the insulating layer is not only for heat retention, but more importantly as an oxygen barrier- the antimony will combine with any available oxygen (and form the resulting oxides) more easily than it will combine with the lead. Occasional gentle stirring helps, but do not stir vigorously as that introduces more oxygen into the melt. It takes a while, but no high heat is needed. I like to think of it as doing it the same way one would make a fine stew- moderate heat, cover, occasional stirring, cook a while, and come back later and enjoy.

BTW, the "plus metal" mentioned by Ricochet was also sometimes called "toner metal".

[Ricochet]

BTW, the "plus metal" mentioned by Ricochet was also sometimes called "toner metal".
Nice to know, thanks!

[44man]

I keep my lead at 600* to add antimony.
I buy the small chunks from Bill and his flux.
I never tried it but maybe a big chunk can be broken up with a hammer. Small pieces cut the time way down.

[papa bear]

Bill no longer sells antimony. If I did not already have some I think I would not mess with it.

[leftiye]

Powder the antimony (or make filings - doesn't have to be too fine). Sprinkle it on top of molten lead and stir it in while playing an acetylene rich flame on it. A larger low velocity flame should be good.

[KYCaster]

Powder the antimony (or make filings - doesn't have to be too fine). Sprinkle it on top of molten lead and stir it in while playing an acetylene rich flame on it. A larger low velocity flame should be good.


Leftiye, do you use any flux or just the flame alone? Does the Sb disolve pretty quickly with your method?

Always looking for a better way.
Jerry

[mtgrs737]

A friend of mine got some Antimony from Bill Furguson and alloyed it with lead in his casting pot at casting tempertures. He made a cage out of rebar tie wire and supended it in the moullten lead. When he came back awhile later to check on the progress the cage was empty and the antimony rock was alloyed into the lead.

[Bullshop]

I think I have a couple of jars of pure powdered lab grade antimony I would be willing to trade for something. Think I have a couple solid bars somewhere also. Make me an offer but remember gubermint money is no good here.
BIC/BS

[lwknight]

It sounds like from the earlier posts that you do not actually have to melt the antimony but, rather disolve it in lead like sugar in hot water.
This is all good to know. Next thing is to open up a local foundry. LOL!

[Ricochet]

Be careful with the powdered stuff. Antimony's toxic and flammable.

[sleeper1428]

While I'm quite sure that antimony can be melted into a melt of lead/tin at normal casting temperatures, the use of an appropriate flux will reduce the time required for this addition to less than 3 minutes. The flux necessary is a zinc/ammonium chloride crystalline flux that used to be sold by Leading Edge Tool Service (LETS) as Alloyer's Flux but now is only available from a commercial outfit by the name of Zaclon under the name of Kleanrol flux. Using this flux makes the job of alloying crushed/pulverized antimony into the lead/tin melt simplicity itself. Just mix a tablespoon full of the flux with the proper amount of crushed/pulverized antimony - do this in a screw top plastic container to keep the toxic fumes and dust contained - and then sprinkle a bit of the flux on the surface of the lead/tin melt to break the surface tension. Add the crushed/pulverized antimony/flux mixture to the melt, stir for a minute or two and you're ready to pour off your lead/tin/antimony alloy melt into ingots ready for future boolit casting.

Now, there are three problems with this method, the first being that the flux is toxic and highly corrosive, as is the antimony dust, while the second is that obtaining this flux may well require a Group Buy since the smallest container of the crystalline flux that they sell is a 50lb pail. If a group of casters - say 10 or so - got together and purchased a pail, they could then divide up the contents and they'd probably have plenty to last for quite a bit of alloying since it only takes a couple of tablespoons full for each 20lb alloy melt. But this brings up the third and last problem and that is the storage of this flux. It is highly hygroscopic and will set up to a hard cake form if allowed to be open to air for any amount of time. So that means that it has to be well sealed in vacuum bags in order for it to retain its loose, crystalline character. Fortunately, if it does get access to air and ends up in a hard, caked form, one can still cut it up and crush it back into a coarse, powdered form that will still work just as well as the original. I checked this out with Bill Ferguson before trying it and while he had no experience doing this, he felt that there would be no problems and indeed, he was correct. As you might have guessed, I have a reasonably good supply of the original Alloyer's flux on hand as well as nearly 100 lbs of pulverized antimony, all purchased when LETS went out of business several years ago. Bill Ferguson bought the business but has since dropped the flux from his inventory as well as the pulverized antimony but he is still a well of information in regard to metallurgy and casting technology.

sleeper1428