Antimony, in its pure state

[63 Shiloh]

I am able to source antimony in an ingot form.

My question is: How to add this and successfully flux it with a lead/tin alloy?

Is it a simple case of adding the antimony to my alloy by just putting it in the smelting pot and fluxing?

Any input appreciated Gents.

Mike

[BABore]

Give this guy a shout

http://www.theantimonyman.com/index.htm

I believe he has a special flux for alloying antimony with lead. Pure antimony is toxic like arsenic, so beware

[KYCaster]

The process is pretty simple and has been described here several times.

Search for posts by 44man and KYCaster with key word "antimony" and you'll find what you're looking for.

Jerry

[lwknight]

From eveerything I read, antimony disolves in lead kinda like salt in water.
Also a little tin helps the antimony mix into the lead without floating on top so much.

A big chunk will take awhile to disolve.

[sagacious]

Pure antimony is toxic like arsenic, so beware

Don't fret too much. Metallic (pure) arsenic and metallic antimony are not toxic.

It's compounds such as arsenic trioxide that are toxic. The arsenic and antimony in ww alloy, for example, pose no toxic hazard during hobbyist lead pouring. Good luck.

[sagacious]

Mike,
It's not the same as alloying tin with lead, where one simply fluxes and adds the tin to the melt, and refluxes if necessary. Antimony is a little more stubborn.

Pure antimony is very brittle and shatters like concrete. The usual advice to break up the antimony into pieces results in a lot of antimony dust and tiny fragments. Those tiny fragments oxidize readily and can make alloying difficult. It's easier to work with 1/2"x1/2" chunks than dust. Be advised that alloying Sb with Pb is not always free of frustration.

Flux your lead melt first to remove as much dross/oxide as possible. Keep the melt very hot. Add enough chunks of Sb to almost cover the melt in one layer. Use a propane torch directed at the chunks to melt the Sb. As they heat up, you will see them begin to melt and 'dissolve' into the melt. The propane flame is reducing and contributes to the alloying. Add more Sb and repeat. You will get a fair amount of dross during this process. Do not discard the dross.

The dross is usually best handled separately. Heat it to melting and flux generously with your desired flux-- I use wax. Be careful, and light the fluxing smoke, or be aware that the wax smoke may spontaneously flame up. Stir, or very carefully swirl the pot while fluxing the help break up the oxides and agglomerate the alloy. You may have to flux more than once. Add the recovered Pb/Sb alloy to your melt, and pour ingots. Best of luck.

[sleeper1428]

I've posted this before but I'm happy to do a repost. In regard to melting antimony into lead or a lead/tin mixture, it's actually fairly easy if you have the appropriate flux. Unfortunately, the proper flux - a zinc and ammonium chloride mixture - isn't readily available, at least not in small amounts. It used to be marketed by LETS (Leading Edge Tool Service) as Alloyer's Flux (20+ years ago) and it's a very active flux that is relatively toxic in and of itself. Today this flux goes by the name 'Kleanrol' and is marketed by the Zaclon Corporation but when I last checked it only comes in barrel size quantities. However, if you happen to have access to this flux, adding pulverized antimony to a lead or lead/tin mixture is simplicity itself and can be done at normal lead smelting temperatures of 700F - 800F.

By the way, Bill Ferguson - The Antimony Man, no longer sells this special flux. The flux he does handle is for use with normal lead alloys and is not meant to be used to aid in the addition of antimony to a lead or lead/tin melt.

As has been pointed out, it is possible to alloy antimony into a lead or lead/tin melt without the use of an active flux as described above but it's going to take time, patience and a higher than normal melt temperature to achieve your goal of alloying antimony into your melt. With the appropriate flux, it takes less than a minute to do the same thing and the temperature of the melt will not have to be any higher than you would normally use, 700F to 800F.

sleeper1428

P.S. - I just now checked on the Zaclon Inc website and Kleanrol Flux crystal is now available in 50lb steel drums. Now, while that's far more than any one person will likely use in a lifetime, it might be something to think about as a group buy. Transportation of the crystal form is NOT regulated by the DOT so it could be repackaged and sent via USPS flat rate boxes. The only catch would be that the repackaging would have to be done in such a manner as to assure that the new containers were fairly moisture proof since this flux is very hygroscopic and will 'cake' up quite easily, necessitating the crushing of this hard cake before use. Anyway, it's something to think about.

[63 Shiloh]

Thanks for the great info fellers,

I looked up the melting point of antimony and called a friend who has a furnace that he uses to melt down gold. He is a keen prospector, if it can melt gold it will melt antimony I am guessing.

The fluxing procedures and the use of the product Kleanrol outlined by fellow casters is new info for me, thanks to all.

I have a few contacts in the mining game and will talk to some of them about this specialised flux and availability in Australia.

OT, I read so many good things about Kroil I decided to try some, could only find it in 200l drums, a little more than I will ever need! (About 50 US Gal)

I am keen to do some experimentation with this, will keep you posted.

BTW, is it necessary to use specialized PPE with antimony and the Kleanrol Flux?

Thanks Gents,

Mike

[shotman]

Brownell sells a Marvel flux and welding shops have a braseing flux both will work and may be same thing -look the same- I have not had a problem but I do run the temp up to about 900 the antimony will blend right in
I have the pure stuff but is in chunks that look like crystals would bet ingots would take a while to melt

[felix]

Sleeper, if you can get the proportions of the zinc and ammonium chlorides, or whatever, I know folks who will get the stuff and we can make the "flux" ourselves, via Wilgen/Blammer or anyone who will partake into the adventure. Before ordering quantity, we would use freebe samples to assure success. ... felix

[KYCaster]

I've been adding Sb to my alloys for quite a few years now. I started out with the "special flux" from The Antimony Man and gave up on it because of problems with moisture, clumping, foaming and generally poor results.

Boolit loob works just fine as a flux.

High temperature is unnecessary, I get better results by reducing the temp to the slushy stage.

My method doesn't take any longer than the method described by Bill Ferguson. As a matter of fact, since I don't have to deal with problems associated with the Zinc/Ammonia flux my time involved is substantially less.

WHAT??? Problems with the "special flux"???? Let me explain.

As has been mentioned, the flux is extremely hygroscopic...it absorbs moisture from the air. Following Mr. Ferguson's advice I put enough for my immediate use in a large salt shaker and stored the remainder in double zip bags and inside a Tupperware bowl with air tight lid. Within 24 hours the flux wouldn't flow through the salt shaker. Applied to the melt in this condition the moisture causes the flux to foam and the Sb particles become encapsulated in the foamy flux...a difficult situation to deal with.

Within a month the flux that was stored in the air tight container had absorbed enough water to be useless. Eventually it hardened into a solid block. In order to use it I had to crush it, sift it to remove the lumps and dry it in an oven immediately before use.

Even when everything goes as planned the flux doesn't work well with fine particles of Sb. Mr. Ferguson recommends screening the Sb to remove the fines. The small particles become encapsulated in the flux with no easy way free them so they can dissolve.

I don't have any of these problems with the flux I use.

Jerry

[StarMetal]

I wonder if Homeland Security would watch large purchases (55 gal drum) of that flux zinc and ammonium chloride......ammonium chloride is used in explosives. Not sure I would want to be on the list of purchasers.

[felix]

If those are the situations, maybe we should scratch that stuff off of the list for boolits. I actually know zero about the zinc and ammonium chlorides as fluxes. Perhaps, if some of these two were around here I would use them on nut trees. However, an overdose of zinc would require a copper to compensate. Both (micro) nutrients require care in terms of amounts, and are usually applied with iron and maganese as all four nutrients are required to maintain long term nut tree balance. ... felix

[hammerhead357]

L E T S flux is nothing more than sodium formate. It used to be available at large commercial drug stores and may still be. It used to be cheap. Dont know about now.
It's the same stuff that Brownells sell I am told. Don't know that for sure so check it out....Wes

[dwebb210]

I would think dissolving the chunk would be easier due to less oxidation.
The oxide layer shields the antimony from the molten lead, and slows dissolution.

I would keep it as close to one piece as possible.
It might take longer, but you probably won't need to flux at all.

In my experience, flux just makes a mess of things anyway, in regards to
alloying with antimony. Using a propane torch to reduce the oxides back
to metal worked a lot better for me.

[sagacious]

If you melt the fines into blobs/beads with a propane torch before alloying, less dross is produced.

I alloyed some antimony into a 99Pb/1Sn melt yesterday, using the same process as described in my previous post. Worked fine.

Today, on the suggestion that Marvelux works well for this application, I dragged out the old can and began fluxing some Sb into a 99Pb/1Sn melt. The melt was fluxed with wax, and the small amount of dross skimmed. Melt kept at 650-700*F, as per Marvelux use instructions. Small amount of Marvelux added, and upon it's melting, Sb chunks and particulate added to the melt. Seems to work OK, but the fines do become entrapped in the flux. That's no good.

Another melt was begun, as above. Marvelux added and Sb added, but this time, I directed a low propane flame at the Sb, as I would when not using flux. The result was unexpected: FIRE. The decomposition products or reaction products of the Marvelux + Sb produced a popping, very short but strongly persistent, fuzzy orange flame. The amount of fire and popping was enough to cause concern. I smothered the flame with a stirring implement. I will not be repeating that experiment.

The interesting thing is that the fire was confined to the area where the Sb was. The entire surface of the Marvelux did not burn, only the area with Sb dust. That an oxidizing reaction happened with Marvelux indicates to me that it may not be as well-suited for alloying Sb as one might hope. I'll have to ponder the likely chemical reaction, but evidently, Marvelux + Sb + ignition source ---> FIRE. Use caution. I reckon I'll keep alloying SB as previously outlined.

[sleeper1428]

L E T S flux is nothing more than sodium formate. It used to be available at large commercial drug stores and may still be. It used to be cheap. Dont know about now.
It's the same stuff that Brownells sell I am told. Don't know that for sure so check it out....Wes

Sorry if I wasn't completely clear in regard to LETS flux products. Back when I was buying and using LETS products, they had two (2) fluxes, one that was marketed simply as LETS Flux and one that was marketed as LETS Alloyer's Flux. As you said, the plain LETS Flux is indeed very similar to the Mavelux flux sold by Brownells - I still have several plastic jugs of this LETS flux that I'm still using - while the LETS Alloyer's Flux was indeed the zinc/ammonium chloride mixture. In fact there were warnings printed on the jugs of this flux stating that it was not for use in normal lead alloy casting and should be reserved for alloying pulverized antimony into lead/tin melts. Fortunately, I also purchased several pounds of this Alloyer's Flux before LETS went out of business and although I do have to break up the caked flux and then crush it before using it, it still works great.

sleeper1428

[sleeper1428]

I've been adding Sb to my alloys for quite a few years now. I started out with the "special flux" from The Antimony Man and gave up on it because of problems with moisture, clumping, foaming and generally poor results.

Boolit loob works just fine as a flux.

High temperature is unnecessary, I get better results by reducing the temp to the slushy stage.

My method doesn't take any longer than the method described by Bill Ferguson. As a matter of fact, since I don't have to deal with problems associated with the Zinc/Ammonia flux my time involved is substantially less.

WHAT??? Problems with the "special flux"???? Let me explain.

As has been mentioned, the flux is extremely hygroscopic...it absorbs moisture from the air. Following Mr. Ferguson's advice I put enough for my immediate use in a large salt shaker and stored the remainder in double zip bags and inside a Tupperware bowl with air tight lid. Within 24 hours the flux wouldn't flow through the salt shaker. Applied to the melt in this condition the moisture causes the flux to foam and the Sb particles become encapsulated in the foamy flux...a difficult situation to deal with.

Within a month the flux that was stored in the air tight container had absorbed enough water to be useless. Eventually it hardened into a solid block. In order to use it I had to crush it, sift it to remove the lumps and dry it in an oven immediately before use.

Even when everything goes as planned the flux doesn't work well with fine particles of Sb. Mr. Ferguson recommends screening the Sb to remove the fines. The small particles become encapsulated in the flux with no easy way free them so they can dissolve.

I don't have any of these problems with the flux I use.

Jerry

It's interesting that you've had the problems described when using the original LETS Alloyer's Flux (zinc/ammonium chloride mixture). I purchased several pounds of this Alloyer's Flux 20+ years ago, along with a sizable quantity of pulverized antimony, and with the exception of now needing to break up the caked flux and then crush the chunks with a large mortar and pestle, I've had no problem whatsoever with getting the pulverized antimony melted into the lead/tin alloy, even the smallest particles. I simply follow the original LETS instructions which say to put the required amount of antimony in a plastic container (I use an empty qt size peanut butter jar) and then add about a tablespoon of the crushed Alloyer's Flux (actually I've found that I can use much less than a tablespoon full, more like a teaspoon full) and shake well with the top on the jar (remember, antimony dust and this flux are both fairly toxic). Then I sprinkle just about half a teaspoon full of the crushed flux on the lead/tin alloy melt - this is supposed to, and does, break the surface tension and prepare the melt for the addition of the antimony. Then I shake in the pulverized antimony/Alloyer's Flux mixture, stir for a minute or so and I'm ready to pour off the new alloy into ingots. The instructions actually say that mixing in the antimony may take up to 3 minutes or so but I've never had to stir more than one minute before all the antimony has gone into solution.

A few years back, Bill Ferguson and I discussed whether it would be necessary to dry out the hydrated and freshly crushed Alloyer's Flux and as a metallurgist he opined that since the moisture taken up by the hygroscopic flux was in the form of a hydrate and thus heating would involve a change from a hydrated form to a gaseous form (as opposed to a liquid form to a gaseous form) in order to form steam, that it was probably completely unnecessary to dry out the flux in an oven prior to using it. Working on his assumption, I went ahead - taking all due precautions attendant to an unexpected visit from the Tinsel Fairy - and added the flux/Sb mixture without any prior drying and had absolutely no problem whatsoever. And since that time I've done this time after time, always with the same results. However, I have to agree with you that if you wanted to use it in a salt shaker as you've described, then I suspect you'd actually have to dry it out since the hydrated flux would probably clump together and clog the holes in the shaker.

Perhaps it's the mixing of flux with the pulverized antimony prior to putting the mixture into the lead/tin melt that is making the difference - I know that in the instructions on doing the alloying it states that by mixing the flux with the pulverized antimony you are coating all the particles with flux thus beginning the breakdown of surface oxides and thus allowing the antimony, both small and large pieces, to go into solution more easily and rapidly. Also, the breaking of the surface tension with just a bit of Alloyer's Flux before adding the flux/Sb mixture may add to the ease of the operation.

Obviously, what you're doing works for you so I'm in no way saying that you're doing anything wrong. I'm just saying that for me the use of this zinc/ammonium chloride flux works smoothly and easily and I've probably alloyed well over 1000+ lbs of hardball/Taracorp Magnum alloy (92-2-6) over the years without a single problem. So like the old saying goes, there's more than one way to 'skin a cat'......

sleeper1428

[KYCaster]

If you melt the fines into blobs/beads with a propane torch before alloying, less dross is produced.

I alloyed some antimony into a 99Pb/1Sn melt yesterday, using the same process as described in my previous post. Worked fine.

Today, on the suggestion that Marvelux works well for this application, I dragged out the old can and began fluxing some Sb into a 99Pb/1Sn melt. The melt was fluxed with wax, and the small amount of dross skimmed. Melt kept at 650-700*F, as per Marvelux use instructions. Small amount of Marvelux added, and upon it's melting, Sb chunks and particulate added to the melt. Seems to work OK, but the fines do become entrapped in the flux. That's no good.

Sagacious, there's no need to melt the fines. I don't even bother screening out the fines any more. I use everything smaller than ~1/2 in. or so and the only dross I skim off is oxidized flux.

When I was buying Sb from Bill Ferguson and talking to him often about my issues with the LETS flux, he sent me about 30 lbs. of fines he accumulated from his screening and I was able to use it without any major issues.

All those irritating issues with hygroscopic fluxes are a thing of the past. Life is good.

Jerry

[sagacious]

Jerry,
I'll try wax next time during the initail alloying of the antimony. I think the main practical difference between your process and mine is when the flux is applied-- I re-flux the dross after the alloying is done. That gives me the least possible waste.