What in the world do I have here? Soft lead with zinc?

[Rickf1985]

A while ago I posted about a home made tester using a punch but then I ended up getting the Lee tester. I was looking to find out what some big home made weights are that I have that are many, many years old. So I cut off a chunk and it came out to plain soft lead, a 10 on the scale on the chart. No problem, I will melt them down into ingots to make them more manageable. This is where it gets strange. I spent hours cutting this monster down to pieces that would fit in the Lee melter and once in there it melted quite fast but even at 600 degrees it had a heavy layer of crunchy goo on top that scooped off very easily. I do all of my smelting at less than 700 degrees so that any zinc that finds it's way in there will not melt. So I am thinking this might be zinc but wouldn't that make the lead hard? I was pouring this into my ingot molds and as the day went on I noticed that it was getting harder and harder to get the ingots out of the mold. I thought this was a bit strange since the lead usually just about falls out. The last couple loads I did I was paying close attention to the melting temps, I put the thermometer in before I added more lead and let it solidify around the thermometer and noted the temp at which it did so, 500 degrees. As it warmed up I watched very closely for it to start to melt and noted as soon as it melted at the thermometer and again, right at 500 degrees. This seems very cool for something alloyed with zinc? In the last load as I was fluxing and scooping the trash off the top I felt a big chunk and scooped it out and apparently it was a chunk of zinc. Once it cooled I could dig into it and it would break off and look like pot metal. I emptied the pot by turning it upside down so it was completely empty and I put that chunk back in and it would not melt at a laser indicated reading of 750 degrees. I put it on a piece of metal and hit it with a torch and it melted very easily that way, again, looks like zinc. All of the ingots made with this mix came out frosted if that means anything. SOOOOO. Do I have 55 lbs. of ingots that are good for nothing but sinkers?

Here are some pics to show what I have. Feel free to ask any questions you may have. I have htree more of these weights but I wam thinking they are probably not good for much else than weights.

[Rickf1985]

Last three pics.

[poppy42]

Probably has zinc in it. 10 is a little hard for pure soft lead (6 to 8 for pure lead). Put a few drops of pool acid (muriatic) on it. If it bubbles and fizzes, it’s got lead in it. No reaction and it’s lead. No worries if it does have zinc, it’s probably not a high percentage. You can use Garden sulfur to remove zinc from lead. Especially in small percentages. Search the stickies I’m sure there’s a thread explaining it to use.

[Rickf1985]

When I said 10 that was a little misleading, that was 10 on the Lee scale in their microscope which equates to 6 or below on the hardness scale. Thanks for the acid tip, I forgot all about that one and I do have some acid. Will have to try to find the sulfur thread. I am thinking that is probably something I would want to do when the neighbors are working!

[poppy42]

I have a Lee hardness tester. 10 in not pure soft lead! When I make Wheel weight ingots I get anywhere from 11 to 13, unless I mix in a bunch of stick on’s! Then 10 or 11 is not uncommon. All of which I simply add about 2% tin to come up with my pistol alloy. I have no need for anything harder for my pistol Boolets. Others needs may vary but for me they are perfect

[Rickf1985]

Ok, I have the Lee chart right here in front of me and it only goes to .079 which is 8.0 hardness and my lead is showing up at .10. every .010 is 1 full digit on the hardness scale so I am jumping .020 which would be 2 digits on the scale hence 6.0 hardness. Unless you are working off of a different scale?

[poppy42]

OK I’m not exactly following what you were doing I am looking at the Lee hardness scale chart. If the size of the demple is .079You have a hardness on the BHN scale of 8.0. If the size of your dimple measures .071 you would have a BHN of 10.1. Pure soft lead has a BHN of around 6 to 8! All I’m trying to say is that a BHN of 10 is not pure soft lead. I think what we have here is a failure to communicate. Lol Technically all the sources I find that say pure lead has a BHN of five I’ve never seen any for our purposes that soft as I don’t purchase pure soft lead.

[Springfield]

First off, if you are going to melt larger pieces like that you need a bigger pot. Second, fluxing at 600 degrees is not hot enough to return all the stuff that floats to the top back into the mix, in my experience. Third, what are you fluxing with? And fourth, if all the metal is coming from one big piece why are you worried about "zinc getting into it" ? If the zinc is already in the chunk chances are you will not manage to get it out, at least not just by melting and skimming. I betting if you up the temp and flux a bi more that crunchy stuff will disappear.

[poppy42]

+1 on that also

[Conditor22]

[Rcmaveric]

BHN of 10 is my normal mix for almost everything.

Just some oxide. Flux the crap out of and then cover the top with borax to prevent it from corroding. No real way to say. What's in. Doubt its zinc though. Zinc issues show up more as being a real pita to cast with and the spout freezing over and horrid bulketfill out.

That skum was just oxides from. I get that some times if I don't do a good job fluxing. I flux with saw dust and let it cook lol. Then finnish off with a couple good bee wax or smell good candles. Wifes stolen smell good candles is the secret ingredient to homing bullets if you didn't know.

Sent from my SM-N970U using Tapatalk

[Rickf1985]

First off, if you are going to melt larger pieces like that you need a bigger pot. Second, fluxing at 600 degrees is not hot enough to return all the stuff that floats to the top back into the mix, in my experience. Third, what are you fluxing with? And fourth, if all the metal is coming from one big piece why are you worried about "zinc getting into it" ? If the zinc is already in the chunk chances are you will not manage to get it out, at least not just by melting and skimming. I betting if you up the temp and flux a bi more that crunchy stuff will disappear.

Believe it or not with those large pieces in there it melted down in five minutes or less. That pot works great. I don't generally do large stuff like that so getting a larger pot is not worth it for me unless I can find a turkey fryer cheap. Then I will cut down a propane tank I have and smelt in that. But I have always had good luck with smelting at lower temps and keeping the zinc wheel weights out of the mix. They just float with the clips. I did take it up to 750 0n a small run to see if the mush would melt and it did not. it did not change at all. Now that the pot is completely empty I might take all that sludge and put it in there and run it up to 800 and see if it melts. Like I said, the one chunk in the mix I fished out that would not melt at 750 did melt easily with a propane torch. I just did not want to ruin a 20 lb. pot of lead just to find out that, yes, zinc will alloy at 800 degrees and now I have junk. I may have junk anyway but at least I didn't push it.

[Rickf1985]

OK I’m not exactly following what you were doing I am looking at the Lee hardness scale chart. If the size of the demple is .079You have a hardness on the BHN scale of 8.0. If the size of your dimple measures .071 you would have a BHN of 10.1. Pure soft lead has a BHN of around 6 to 8! All I’m trying to say is that a BHN of 10 is not pure soft lead. I think what we have here is a failure to communicate. Lol Technically all the sources I find that say pure lead has a BHN of five I’ve never seen any for our purposes that soft as I don’t purchase pure soft lead.

My dimple is .10

[Rickf1985]

BHN of 10 is my normal mix for almost everything.

Just some oxide. Flux the crap out of and then cover the top with borax to prevent it from corroding. No real way to say. What's in. Doubt its zinc though. Zinc issues show up more as being a real pita to cast with and the spout freezing over and horrid bulketfill out.

That skum was just oxides from. I get that some times if I don't do a good job fluxing. I flux with saw dust and let it cook lol. Then finnish off with a couple good bee wax or smell good candles. Wifes stolen smell good candles is the secret ingredient to homing bullets if you didn't know.

Sent from my SM-N970U using Tapatalk

I usually flux with paraffin wax since that is what I have. I prefer beeswax but at the price of it right now I will stick to the paraffin. I do have regular flux made for this purpose but to me it does no better than the wax and it is sloppy and makes a mess of the pot. I have used sawdust before but then my neighbors think I am burning down my garage. LOL. I will throw a few of the ingots from this stuff back in the pot along with the scum I dredged off and see if it will clean up. What have I got to lose?

[poppy42]

My dimple is .10

I think you have a problem someplace, if you’re coming up with a dimple size of .1. Considering a dimple size of .079 gives you a bhn hardness of 8. That would mean you’re measuring something that’s so soft it’s off the chart. are you sure you’re testing lead and not cheddar cheese? Lol

[fredj338]

It isnt zinc, melt temp is too low & zinc looks more like oatmeal. You have a mystery alloy but maybe have someone with a better tester test it? if it melts at 500deg, it could have a high tin content, like solder?

[Rickf1985]

Ok, This stuff is out to get me! I just tested the nuggets I set aside for that purpose and they came out to 6.2 on the Lee scale which is 13.4 BHN. So I grab one of the full size ingots and test that, 6.2. 13.4 BHN again. I have no idea what is going on but I still have the samples I tested the other day that tested at .10 which is off the BHN scale. I like the new numbers much better but I would like it better if I understood what was going on. I cannot picture the metal hardening that much in one day.

[Rcmaveric]

Testing ingots is unreliable. Best to cast a bullet and test that. Time, voting, and work affects hardness.

Depending on the age of that ingot it could have age softened or work softened. Once remelted you have your base hardness back. Then the hardness will stabilize in about two weeks.

Becarefull, oatmeal or grainy alloy doesn't always mean zinc. High Antimony leads do the same thing. Flux it and crank up the heat. Contamination is only problem when it affects spout freezing and mold fill out. Just keep the zinc level under .12%.

Sent from my SM-N970U using Tapatalk

[Rickf1985]

I am having a problem with my mold filling out BUT, it is a new Lee 6 bullet mold and I have never used an aluminum mold. I have tried filling from a bottom pour and from a ladle and neither are working for me. I dipped the end of the mold in the lead for a while like they say to do to bring it up to temp but I keep getting the same exact pattern of wrinkles every time. I have gone from 600 to 850 degrees on the lead temp and all kinds of methods of pouring and I get the same exact look every time. I find it hard to believe it is me with all that I have tried but I also tried several different types of lead, pure, straight WW and this mix. I am going to dig out one of my one or two cavity steel pistol molds and try that. I am told that starting to learn on smaller than 38 caliber is tough and this Lee mold is 30 caliber. Remember what I said about the lead sticking to the ingot molds? Anything to that? What would cause that to happen? This is a 75 year old Saeco mold that worked perfectly up til this point. I even smoked it and that made no difference at all.

[Mitch]

oops!