Use of Powdered Zinc in Alloying Lead

[Gray Fox]

A while back I got 25 lbs of powdered zinc, hoping to use it in lead alloys. All it does is float on the top of my lead pot. Is it possible to use this, or did I just waste a bunch of money?

[Ole]

Lead melts at a lower temperature than zinc.

You need to get the pot up to around 787 degrees to melt zinc.

Some paper patch guys use zinc to alloy their lead.

Don't try to use a zinc/lead alloy with an aluminum mold.

That's all I know. Most guys that cast try to avoid the stuff.

[sheepdog]

Zinc has no use in normal casting (except mentioned above). Powdered zinc can be used for another great gun use... parkerizing.

[runfiverun]

zinc can be used to make lead harder but in small amounts.
it adds a lot of hardness,but it also causes a lot of problems.
try upping your temp adding some tin and fluxing it in with a flux that will break the surface tension.
powdered antimony gave me the most problems when alloying it in.
you gotta use a verysmall amount of flux a small amount of additive and stir slowly. with a lot of patience.

[leftiye]

Copper can be alloyed by sprinkling it on the surface of lead and playing a torch (I've only used acetylene) on it while stirring it in. Perhaps this method would work on zinc also. Zinc fumes are poisonous (so are lead fumes), so wear a respirator, and ventilate well. Better still, use copper (1%) to harden your alloy. Makes it tougher too.

[Box13]

has anybody used the various silver solder alloys to harden lead?

[armyrat1970]

After having a big problem with zinc contaminated WWS clouging my pot I would not use any zinc in any of my casting alloy, no matter what form. It took quite some time with a number of post on different sites before I found a sure way to clean my pot. I won't go through that again. Stay away from zinc. It has no use in bullet casting alloy. It's okay for fishing weights, or door stops.
This is from the Lee Modern Reloading Second Edition:
"Zinc is bad! One part of zinc in 10,000 parts of lead alloy will ruin its castability."

[Bret4207]

After having a big problem with zinc contaminated WWS clouging my pot I would not use any zinc in any of my casting alloy, no matter what form. It took quite some time with a number of post on different sites before I found a sure way to clean my pot. I won't go through that again. Stay away from zinc. It has no use in bullet casting alloy. It's okay for fishing weights, or door stops.
This is from the Lee Modern Reloading Second Edition:
"Zinc is bad! One part of zinc in 10,000 parts of lead alloy will ruin its castability."

As usual I disagree with Mr. Lees assessment. I'm sure I've had far more than 1/10K zinc in my alloy before. A little zinc wouldn't make your alloy produce bubblegum boolits all the time. Sometimes it takes a while to figure out whats up and to come up wit a fix, but usually a little more heat and a faster casting rhythm works. But then, I'm a ladle guy, not a bottom pour guy so maybe that's part of the difference. I also cast hot so maybe that's part of it. If you're hung on casting at 650-675 degrees I can see where it'd be a huge issue.

None the less I try and avoid any zinc contamination. Headaches are headaches and I've got enough already without looking for more.

[armyrat1970]

As usual I disagree with Mr. Lees assessment. I'm sure I've had far more than 1/10K zinc in my alloy before. A little zinc wouldn't make your alloy produce bubblegum boolits all the time. Sometimes it takes a while to figure out whats up and to come up wit a fix, but usually a little more heat and a faster casting rhythm works. But then, I'm a ladle guy, not a bottom pour guy so maybe that's part of the difference. I also cast hot so maybe that's part of it. If you're hung on casting at 650-675 degrees I can see where it'd be a huge issue.

None the less I try and avoid any zinc contamination. Headaches are headaches and I've got enough already without looking for more.

Hear you about the headaches. I have enough of my own also. I am a bottom pour caster and smelted WWS in my pot before knowing better. I run a hot pot when casting but the alloy clogged my spout from the zinc. I have read before that all of the dross and stuff will rise to the top but after dumping my clogged pot there was quite a bit of zinc lying on the bottom. I had to scrape it out with a knife. It seems it does not all rise to the top. I purchased a RCBS thermometer and will now smelt my WWS in a dutch oven while fluxing with Marvelux, keeping my temps around 700, removing as much dross or zinc as I can, and ladle my ingots. I will melt my ingots in my pot and flux with CFF while casting. It will be the first time I have used CFF but if it works as well as I have read about it, should be able to pour some good boolits. Gonna smelt some WWS this afternoon and just went yesterday and got my propane tank filled. Hope it all goes well.

[runfiverun]

silver will add ardness too it is part of what makes lasercast so hard.
i am in the as usual disagreement with lee camp too.

[Bret4207]

Army- Start using a dry stick to scrape the pot with. You'll be fluxing with the stick (carbon) as you do it. Use a stick long enough to give you a little leverage and keep cutting a square edge as long as your pot seems to have "bumps and ridges". It'll scrape the stuff off eventually with out harming the pot.

[Tom Herman]

Copper can be alloyed by sprinkling it on the surface of lead and playing a torch (I've only used acetylene) on it while stirring it in. Perhaps this method would work on zinc also. Zinc fumes are poisonous (so are lead fumes), so wear a respirator, and ventilate well. Better still, use copper (1%) to harden your alloy. Makes it tougher too.

Hi Guys,

I don't know how finely powdered the Zink is, but be warned that very finely powdered zink is actually explosive! You may get more than you bargained for if you try to use a torch to melt it in.
I don't see why anyone would try to mix lead and zink... Most of us try to keep the Zink out!!!!
Methinks you did a boo-boo picking up the zink. Sell it to folks making cannon projectiles.

Happy Shootin'! -Tom

[Tom Herman]

has anybody used the various silver solder alloys to harden lead?

Silver solder contains varying amounts of Cadmium, which is not healthy for you. Do yourself a favor and avoid it like the plague.

Happy Shootin'! -Tom

[trevj]

Silver solder contains varying amounts of Cadmium, which is not healthy for you. Do yourself a favor and avoid it like the plague.

Happy Shootin'! -Tom

SOME silver solders contain cadmium!

Read the fine print.

It's getting harder to get the stuff with Cadmium in it these days. Most is labeled as cadmium free.

For bullet purposes, that may be a good thing, but the Cad free stuff does not work as well for it's intended purpose, at least for what we were using it for( high pressure gas line fittings)
.
Cheers
Trev

[armyrat1970]

Army- Start using a dry stick to scrape the pot with. You'll be fluxing with the stick (carbon) as you do it. Use a stick long enough to give you a little leverage and keep cutting a square edge as long as your pot seems to have "bumps and ridges". It'll scrape the stuff off eventually with out harming the pot.

Bret did that last night as I smelted some WWS in my cast iron dutch oven for the first time. Checked every weight with a pair of pliers and kept my temps around 700 degrees. Found only one I thought was steel or zinc and threw it out. The temps got a little high at times but no more than 710. I fluxed with MARVELUX. Poured ingots in muffin pans. Got about 35lbs. of ingots from the WWS with some added range pick-up lead. The wooden stick i used for stirring would burn down and I am sure left some ash that skimmed off when fluxing but it probably helped for oxidation. Learned one thing though. Next time I will only use a muffin pan for ingots that has been used before or coat it with something. The ingots would not even fall out of the new muffin pan and I have a couple of bandaids on my fingers from using a pair of pliers to peel every one of the 12 ingots out of the mold. Had to actually peel the metal from each cup. One by one. And didn't have a pair of gloves so I have a few bandaids on me from the sharp edeges. Won't do that again. Poured twelve other ingots in a muffin pan my wife had used before and maybe it had some oil or something left in the cups but the ingots dropped right out. And of course now I have to get her a new muffin pan. But it's all good. I've got some good ingots I can use in my pot to cast with and I can cast a bunch of boolits with 35lbs of alloy.

[Slow Elk 45/70]

Gray Fox, I bet you were not looking for Zinc to do what you wanted, fill out / harden lead ??:confused:

As most people have said , Zinc is considered a contaminate by most folks casting Boolits.
If you want harder/stronger, use tin & antimony. 25 # of zinc ???? Wow, you been had buddy . [smilie=b: :violin:

[Ancesthntr]

armyrat - what is "CFF?"

[armyrat1970]

armyrat - what is "CFF?"

Hi Guy. Look in the Swappin and Selling forum for Pat Marlins California Flake Flux. If you have trouble finding it get back and I will try to give you a link.:drinks:
By the way, welcome to the forum. Lived a little southwest of San Antonio back in the mid to late '80s in a little town called Pearsall. About 100 miles north of Laredo. Everyone from that town would let you know that is where George Strait is from. They were proud of him.

[DLCTEX]

According to Lyman's Cast bullet Handbook no more than 2% zinc will alloy with lead. The rest will separate, which is what clogs bottom pours and makes "oatmeal" rise to the top of the melt. The excess zinc will be in raised areas floating on top of the melt, if the melt is hot enough to keep the zinc molten. By skimming these raise areas, or by lowering the temp until the oatmeal forms and removing it, the excess zinc can be removed. I find that the 2% does no harm in boolit casting, but may require hotter temps than normal. The boolits will have a color of sterling silver and will not frost as easily as WW. This has been my experience so far.

[Willbird]

According to Lyman's Cast bullet Handbook no more than 2% zinc will alloy with lead. The rest will separate, which is what clogs bottom pours and makes "oatmeal" rise to the top of the melt. The excess zinc will be in raised areas floating on top of the melt, if the melt is hot enough to keep the zinc molten. By skimming these raise areas, or by lowering the temp until the oatmeal forms and removing it, the excess zinc can be removed. I find that the 2% does no harm in boolit casting, but may require hotter temps than normal. The boolits will have a color of sterling silver and will not frost as easily as WW. This has been my experience so far.

I just bought a gallon of muriatic acid and confirmed my suspicions that a batch of alloy I made up has some zinc in it. It can be used, but it does not cast as nicely as metal with no zinc. I am trying to trace down the source of contamination and it is looking like melting indoor range scrap with as lot of bullet jackets and jacket dust in it may be the culprit, gilding metal jackets are 5% zinc, and I may have used too much heat melting the range scrap.

[Ancesthntr]

I am trying to trace down the source of contamination and it is looking like melting indoor range scrap with as lot of bullet jackets and jacket dust in it may be the culprit, gilding metal jackets are 5% zinc , and I may have used too much heat melting the range scrap.

I would think that the gilding metal would rise to the top much as zinc does, since it is lighter than lead. I think you must've really used a lot of heat, as Wikipedia says that brass (of which gilding metal is one of many types) has a melting point of 900-940 degrees Celsius. It shouldn't have melted in, but may have clogged up your furnace's mechanism.

By weight, it would seem that you have only a very small percentage of zinc in your alloy, as the 5% zinc in the gilding metal would be cut substantially by the lead, tin and antimony in your range lead - though your story is a good warning to be careful. It is also a good reason to buy a thermometer, so that we can keep the heat low enough to avoid this problem.

[Willbird]

I would think that the gilding metal would rise to the top much as zinc does, since it is lighter than lead. I think you must've really used a lot of heat, as Wikipedia says that brass (of which gilding metal is one of many types) has a melting point of 900-940 degrees Celsius. It shouldn't have melted in, but may have clogged up your furnace's mechanism.

By weight, it would seem that you have only a very small percentage of zinc in your alloy, as the 5% zinc in the gilding metal would be cut substantially by the lead, tin and antimony in your range lead - though your story is a good warning to be careful. It is also a good reason to buy a thermometer, so that we can keep the heat low enough to avoid this problem.

Well I did weigh the amount of jackets I was getting out of say 100lbs of range scrap, and it was around 10%, so that would be 10lbs of jackets, and if the molten metal absorbed all of the zinc from them(and it surely did not) the end result would be 1/2 lb in 80 lbs of lead so the MOST that should be there is .6% of zinc.

Bullets cast from the contaminated batch turn a nice golden brown if they are heat treated at 450 degrees, they also bubble quite a bit if dropped in muriatic acid...not an alka seltzer fizz by any means, but small fine bubbles.

I left some bullets IN the mold when I put the mold on the hot plate to keep warm between runs and they turned brown and purple.

Samples of some range scrap I just melted turn deep dark grey if dropped into muriatic, but they do not fizz to any great degree.

it is tough to melt the stuff cold with all the bullet jackets in it.

Experiments continue :-).

[Ancesthntr]

it is tough to melt the stuff cold with all the bullet jackets in it.

That was a question I had: how easy is it to melt the lead from the jacketed bullets? I would think that the lead alloy inside would melt out, leaving the jackets floating on top, but you seem to say otherwise.

By the way, gilding metal is exactly the same composition as the pre-1982 penny - 95/5 copper-zinc alloy. Though it is illegal to melt down pennies and nickels, I do wonder what some scrap yards would pay for ingots of gilding metal?

[Willbird]

Here is a bullet from the batch of alloy I suspect got contaminated. With it is a slice off an ingot of newly smelted indoor range scrap. Both were in Muruatic for about 1 hour. The shiny bullet is unmolested.

Also when I smelted the small batch of straight range scrap that slice came from the dross on top was an almost indigo color. About the color of the square on the top right.

http://www.december.com/html/spec/color4.html. I have another small batch cooking right now, if I can get a picture I will. It is a LOT different color than the slight bluish haze common on molten lead.

Most of the bullets hit a steel plate that was at a 45 degree angle, so they are burst open, not bad to melt the lead, but it takes some stirring and mixing to get it all melted so the jackets float on top. More of a PITA then melting WW by far.

Bill

[Tom Herman]

SOME silver solders contain cadmium!

Read the fine print.

It's getting harder to get the stuff with Cadmium in it these days. Most is labeled as cadmium free.

For bullet purposes, that may be a good thing, but the Cad free stuff does not work as well for it's intended purpose, at least for what we were using it for( high pressure gas line fittings)
.
Cheers
Trev

Hi Trev! I haven't had the opportunity to use silver solders, but it appears that they have become politically correct as well, and reduced or replaced the cadmium over time.
I learn something every day...

Happy Shootin'! -Tom

[Tom Herman]

That was a question I had: how easy is it to melt the lead from the jacketed bullets? I would think that the lead alloy inside would melt out, leaving the jackets floating on top, but you seem to say otherwise.


Jacketed bullets melt quite nicely, and the jacket material floats to the top. I do it all the time.
The caveats are to make sure the stuff is DRY, and that any jackets that are sealed are breached so they don't squirt hot lead.
I wash my range scrap, which gets most of the crap off. Then I stick them on a dedicated cookie sheet that's never used for food, and heat it at 250 degrees in the oven for an hour.
I either flatten fully sealed bullets with a hammer, or nick the jacket with a cable cutter.
The stuff will melt, the jackets float to the top, where they can then be skimmed off.
The lead is very soft...

Happy Shootin'! -Tom

[armyrat1970]

I just bought a gallon of muriatic acid and confirmed my suspicions that a batch of alloy I made up has some zinc in it. It can be used, but it does not cast as nicely as metal with no zinc. I am trying to trace down the source of contamination and it is looking like melting indoor range scrap with as lot of bullet jackets and jacket dust in it may be the culprit, gilding metal jackets are 5% zinc, and I may have used too much heat melting the range scrap.

Well that's not good to hear. I just smelted around 35lbs of WWS and poured ingots for casting but threw in about 2 lbs of range pick up bullets with gilding metal jackets to smelt the lead from them. I did keep my temps low and hopefully I did not get any zinc contamination in them. I guess I will find out when I try to cast from these ingots.

[Willbird]

Well that's not good to hear. I just smelted around 35lbs of WWS and poured ingots for casting but threw in about 2 lbs of range pick up bullets with gilding metal jackets to smelt the lead from them. I did keep my temps low and hopefully I did not get any zinc contamination in them. I guess I will find out when I try to cast from these ingots.

A gallon of muriatic was only a little over $4 at the hardware store. Store the stuff OUTSIDE though because the fumes will make anything and everything steel or iron in a building rust. There may be a greater issue with indoor ranges because all the bullets get beaten onto steel ? I got a LOT of greenish dust as dross when I smelted the stuff I have.

The batch of 50/50 I have that is contaminated to a degree can still be used, but you have to keep the temp up (which I do anyway) and keep the mold HOT by putting it on a hot plate when you remelt. I was casting Lee 45 and 10mm TC bullets with it and they were wanting to not cast nice sharp edges on the grease grooves unless everything was just perfect.

Bill

[armyrat1970]

That was a question I had: how easy is it to melt the lead from the jacketed bullets? I would think that the lead alloy inside would melt out, leaving the jackets floating on top, but you seem to say otherwise.

By the way, gilding metal is exactly the same composition as the pre-1982 penny - 95/5 copper-zinc alloy. Though it is illegal to melt down pennies and nickels, I do wonder what some scrap yards would pay for ingots of gilding metal?


You are correct as long as they are not fully encased. If the bullets have a hollow exposed lead base or a semi-jacketed or hollow point the lead will melt right out and the jacket will float on the top of the melt. If any part of the bullet has exposed lead it will smelt and flow out. Even if just a crack in the jacket. If fully encased and you can split the jacket in some way you can get the lead alloy out and the jacket will float on top on the melt.
Selling at a scrap yard? The light weight of the jackets would mean you would have to have????? before you would have enough to even try to sell for any amount of money. I have saved the tabs from my Bud cans, and I drink quite a few, for sometime now, trying to fill up a gallon jug before I sell them for scrap as this is pure aluminum and worth more. The jug is about 2/3rds full and weighs about 2lbs. Not much cash for that. How long would it take you to get a gallon jug full of jackets, much less have enough to pour ingots with if you can smelt and pour them? And why even pour ingots from the jackets anyway?