Ahhhhh, crud...

[220swiftfn]

Well, add me to the list..... About 110 lbs of bullet alloy zinc'd..... Didn't come from the WW I smelted, didn't come from the 20/80 bar solder either. That means that the "pure" lead that I got really wasn't.... :evil: Silver mayonaise :-? I tried to salvage with sulfur, but after more than a pound of the stuff I was still pulling out zinc..... :shock: on the up side, a 6 quart dutch oven makes a killer ingot mold [smilie=s:


Dan

[docone31]

No biggee.
Go to some roofing contractors and get some roof boots. Melt at high temp the melt, and toss in the boots. This will stretch out the zinc/alloy and sweeten it up. Actually won't take much to do that. Make sure you stir it a lot. That is what makes a difference with me. Figuire, as much roof boots as you already have. Water quenched, makes a good hard casting. Holds lube well, sizes well, fires for me with no leading.
I intentionally mix zinc in my alloy. Always did, and it works for me.

[lwknight]

I've told this before but I will repeat it now.
I melted some zinc into lead on purpose and it did get a lot of oatmeal looking dross that I
scrape off. Then after pouring into ingots , remelted and got the same thing several times.
Finally I thought that I got the zinc drossed out and poured the lead into thin puddles and let cool.
After it cooled I picked up a couple and bent it easily with my fingers. I let it sit on my bench for couple weeks or so then tried to unbend it. It had gotten so hard that it would not be moved with human fingers. I used tools to try to bend/unbend it and it was so hard that it only broke.

There was no way that I could flux that zinc back in , so evidently lead will hold only a very low percentage of zinc.

[sagacious]

Something is missing here. Not from ww's, not from solder..... must be from the 'pure' lead.

Lead with much zinc component will be quite hard. Few would confuse it with pure, soft lead. If your pure lead was soft, then there was no zinc in it. Something else is the problem.

"Silver mayonaise" is a good description of antimony dross. You do not describe any casting problems whatsoever, just an odd looking melt. What method did you use to determine that zinc was in the melt... and exactly what is the problem that you're having with the alloy?

[mac1911]

If you where to send out a sample to rotometals for a complete analysis they could tell the zinc content, right. I have a chance to grab 300-500lbs of ignots with the warning that the zinc wheel weights where melted in to it also. How much is unknown. This lead was intended to made into ballast for large remote control sailboats?? Anyways, thought of sending in a sample to see what I really will have.

[lwknight]

Hey mac , if you get the ingots cheap enough , you could at worst resell them as lead to scrappers.

[docone31]

Lead only holds a small percentage of zinc, and zinc holds a small percentage of lead.
If you really heat it, then let it come down in temp slowly, it will eventually clump the zinc that is out of alloy on the top. That can be scooped out, the rest will indeed make an hard alloy.
I like the alloy I get, so I try to create it.
When I get that alloy, I then mix in roof boots. That sweetens up the mix. Once you have diluted the alloy, then crank up the heat, flux, then ingot it. Unless you use an acid, I doubt you will be able to break the alloy. However, small amounts of zinc does work well.

[220swiftfn]

Sorry, some more info.... I was going for @ 96/2/2 for traditional level .45 Colt. Ingots used from 2 batches of WW that didn't have an issue when I smelted them @600-650. Bar solder is from a reputable source, unfortunately I didn't check the "pure" before alloying. Couldn't get it to flux right, tried varying the temp, nothing helped. It was just leaving a thick coating on everything, so I shut it down for the night. Tested for zinc with mercuric acid, which was confirmed with a pound of sulfur pulling out about 10 pounds of zinc (with more still in it).

Sagacious- I didn't have a problem fluxing the batches when ingoting the WW's, so how would that change when diluting the antimony by adding bar solder and pure to it? (not being snotty, just curious..) the problem with the alloy is just that it's going to be WAY harder than I need/want.

Docone- The other problem is one of repeatability....

Lwknight- That's why i have a prob with this batch!!! :) Too hard for the application!!!



Dan

[docone31]

Repeatability is an issue.
With more and more zinc showing up though, there is hope.
I have fired almost pure zinc useing aluminum molds with good results.

[wistlepig1]

Do I understand it right, is a little Zn a good thing? By a little I have read some say 2%, others 5% and are those numbers by Wt or Vol.??? thanks
The reason I ask is I smelted last week and noted that my ingots rang when droped and seem hard. I was going to test the hardness next week and I was going to acid them but my mother went into the Hospital about that time sso I have been distracted, she 77yrs. thanks

[runfiverun]

about 1.5% is soluble.
and iirc it's muratic acid.

[220swiftfn]

Runfiverun- Oops, mistyped, yes I used muriatic acid...

Dan

[lwknight]

I had about 14 pounds of mystery contaminated lead and I melted and poured it inti a coupling welded on top of my T-post driver. Now I just lift and drop . No more pulling the thing down to drive the posts.

[sagacious]

...
Sagacious- I didn't have a problem fluxing the batches when ingoting the WW's, so how would that change when diluting the antimony by adding bar solder and pure to it? (not being snotty, just curious..) the problem with the alloy is just that it's going to be WAY harder than I need/want.

Dan
Dan,
Yes you are correct, diluting the antimony would not itself necessarily cause any fluxing problem, but it may necessitate a change in the fluxing process.

Adding pure lead to an antimonial alloy does a few things that have proved to make noticeable differences for some folks. First, it increases the melt temp, and as melt temp goes up, so does drossing of the antimony.

Second, as the percentage of lead goes up, the rapidity of the lead drossing and oxide formation accelerates too. There have been a couple recent threads where folks noticed increased drossing when they added pure lead to their ww melt. It definitely can make a noticeable difference in the way that the melt must be managed, and it catches people off guard, as they don't expect it. In one recent thread, the poster had to completely change their fluxing routine after adding pure lead to ww alloy-- almost exactly the same situation as yours, and the same complaint about rapid dross formation. Be advised that while it may not seem that any change in melt maintenance is warranted, it certainly can require a change in how one handles the melt.

It may be worth reviewing this thread, and how it was shown that while zinc-contamination was suspected, it was in fact not the problem: http://castboolits.gunloads.com/showthread.php?t=85431

Im curious as to what happened when you poured hydrochloric acid on the dross. What was the result?

Regards, and good shooting.

[220swiftfn]

Sagacious- "wierd" would definately describe the melt, didn't look like grey oatmeal, it was smooth bright silver and floating on top about 1/4 inch thick. I took the melt up to about 750 trying to flux it back in, nothing.....(but very clean...) The slag that I pulled out with the sulfur did the full blown fizz when I put the muriatic acid on it, so it's definately zinc...

Dan

[sagacious]

Well there ya have it. The hallmark of zinc contamination is an aggresively-forming frothy dross that does not respond to fluxing with wax, which is indeed what you describe. Frothy antimony dross from ww's will respond to hydrocarbon flux. It's a good policy to quarantine all unknown lead alloy until it's been melted and test-poured by itself.

I hope you can adjust the alloy to suit your hardnesss requirement. Regards, and good luck.