Scrap yard lead

[Jim22]

Went to the scrap yard a couple days ago to get some lead. I told them I wanted mostly wheel weights but I got some other stuff as well. I tried to sort the wheel weights to get rid of zinc or iron ones. Then smelted the rest. I wound up with a bunch of stuff that looked like grey oatmeal. Skimmed it off and added more lead so the clips would float. I noticed the surface of the melted lead turned bright purple. Never seen that before. What causes it? Too much heat? And what do you suppose the oatmeral is?

Jim

[ebb]

The oatmeal is zinc. I have been having a rough time sorting my wheel weights also. I wish there was a way to test for lead, with some kind of chemical reaction or color change.

[Dusty Bannister]

There is a sticky to help you sort the WW by appearance.

https://castboolits.gunloads.com/showthread.php?139839-Guide-to-Hand-Sorting-Wheel-Weights

There is a method of testing individual ingots by trying to nip them with side cutters. Zinc alloy resists easy cutting.

A chemical test requires cleaning a spot on each WW and then adding a drop of Muratic acid and if vigorous bubbling occurs, that is an indication of the acid reacting with zinc.

Purple or other colors can be an indication of overheating the alloy. Most often encountered with soft lead, but can occur with COWW alloys.

[Winger Ed.]

Be patient, and bring the temp. up slowly if you think Zinc WW are in the pot.

The Lead ones melt at a lower temp, they'll liquify first, and the Zinc ones will float up like the steel clips do.

[bangerjim]

Oatmeal is probably ZN......you did not sort well enough. up to 5% Zn will not hurt anything....just makes your boolits a tad lighter.

Sort VERY well these days. I quit messing with dirty old COWW's over 4 years ago when the result was less than 30% Pb. Not worth the money or my time.


Pure Pb will turn purple all the time. Just hot. Nothing to worry about.

[centershot]

Be patient, and bring the temp. up slowly if you think Zinc WW are in the pot.

The Lead ones melt at a lower temp, they'll liquify first, and the Zinc ones will float up like the steel clips do.

Back when I was messing with wheelweights this worked really well for me. Using nippers also works but it's sssslllloooowwww....

[Cosmic_Charlie]

That oatmeal stuff is very likely antimony. No way you left that many zinc ones in your melt. Turn up the heat and stir that antimony in. I found sorting wheel weights pretty easy. Only missed a few and they floated up with the steel clips. And flux well with sawdust.

[farmbif]

sometimes we learn lessons the hard way, ask me how I know.
before melting down wheel weights I give each and every piece a pinch with a pair of dikes. if I even suspect it is not soft enough it goes off to the side. only the ones that pinch easily go into the cast iron pot for melting. but these days I have more time than money so the time to be sure of what goes in the melting pot is well worth it for me. I've found over the years when I try to rush through something the results are less than good.

[gwpercle]

Oatmeal = Zinc ... it's easy to test wheel weights with cutters or even a pocket knife ... lead cuts , zinc doesn't . If you have mush ...you need to rethink your sorting and testing ...
Whatever you are doing ... isn't working .
What I do is sit down and test every wheel weight ...EVERY wheel weight ... if a magnet sticks ... it isn't lead . If it is hard to cut ... it's zinc . If you can make a good cut into it ... Keep it .

Do not rely on how it looks , the shape , the color or any markings ... Test Em All .
Gary

[gwpercle]

sometimes we learn lessons the hard way, ask me how I know.
before melting down wheel weights I give each and every piece a pinch with a pair of dikes. if I even suspect it is not soft enough it goes off to the side. only the ones that pinch easily go into the cast iron pot for melting. but these days I have more time than money so the time to be sure of what goes in the melting pot is well worth it for me. I've found over the years when I try to rush through something the results are less than good.

Did Your Mamma ever tell you " Haste Makes Waste " ? I wish I had a dime for everytime my Mom told me that and then made me do over something I rushed through !
Maybe these guys will listen when we tell them ...test every weight ...
Thinking you will skim the zinkers off before they melt doesn't work either ... I haven't tried it but others have and it ends badly .
Gary

[The Dar]

Get yourself a piece of threaded rod, run the WW across it. Zinc will ring and lead won't.

[Rickf1985]

If you are running a PID and you keep the temp at 700 the zinc will not melt. You can leave it in there all day and it will not melt. It comes out with the clips. I had the oatmeal bit and I was told it was zinc so I dumped the entire pot, thankfully into ingots. and then I put some acid on them............... Nothing. No fizz, no reaction at all. I was told to try again but this time raise the temp to 720 and flux it well with either beeswax or sawdust. Bingo! The oatmeal was in fact dirt encased in lead. The flux separated it out and I ended up with perfect lead with powder and crap on top which I skimmed off. I am certainly glad I did not toss out 100 lbs. of lead just because everyone swore oatmeal was zinc. If the melt is less than 750 degrees then zinc will not melt. Excessively dirty lead will also give you oatmeal so make sure it stays below 720-730 and flux the hell out of it before condemning it.

[Dusty Bannister]

Rick, this is not correct. Zinc WW will dissolve into solution. Just leave it in for long enough and all you will find is the metal clip.

[dbosman]

This is an observation and question. Am I nearly correct that oat meal means zinc contamination but cream of wheat texture can mean excess antimony. ???

My experience comes from before I quit looking for WWs. I used to sit in the garage and sort by nipping with diagonal cutters. Some of the WWs cut, but they were harder to cut than lead. They did cut though. I melted the whole batch and had what looked like packed fine sand at about 300 degrees. The melt was complete at about 700 degrees, per thermometer. The resulting bullets were over size and lighter than they should have been. I kept that alloy for sinkers and weights for holding stuff down. I painted them so they wouldn't get mixed with known materials.

[Rickf1985]

Well, I left one in a 720 degree pot for 15 minutes and it never changed, I fished it out and it looked just like it did when it went in. And yes, it was zinc and not steel, it was even marked zn.

[Dusty Bannister]

First it was stated that one can leave a zinc WW in a melt all day and it will not melt. Then it was stated that a zinc ww was left in a melt for 15 minutes and it never changed.

I clearly said it would dissolve over time. This is part of alloy maintenance on the LASC.

"More and more wheel weight manufacturers are using zinc, steel, alloy and even plastic weights in place of lead. Zinc weights can be difficult to detect when processing into ingots (some are painted to match tire rim color) and zinc in your alloy will cause all sorts of casting problems. Wheel weight alloy melting point is under 600oF and zinc melts at 787.15oF. When processing your weights into ingots keep the pot temperature at or only a little above 650o and no hotter, the zinc weights will float before they melt. If you see anything floating, remove it immediately."

The reason to remove these weights immediately is to prevent their dissolving in the melt.

Antimony melts at 1167 but will dissolve into lead at normal casting temperatures. It does not melt, it dissolves and takes longer than a few minutes. Small amounts submerged in a casting furnace dissolve in perhaps an hour. This is not new information.

[Rcmaveric]

Flux it. And raise the heat. Mostl likey just Antimony being finnicky.

Antimony in lead some times will seperate and look lumpy like oatmeal. It hits that transition stage and it will look weird. Just rais the heat. Looks similar to zink contamination. Wait till its really high Antimony it looks like wet sand and your really freaking.

Depending on your couldron it actually takes quite a few zinkers slipping by to create a problem.

When i reclaim lead its in 300lbs. Lead contaminated with zink is still castable at .12%. So about around 2/3 a pound of zink would have to slip by me before I had a problem. I am diligent though.

I have also never had zink melt into my lead accidently. I have one slip through every once and awhile but it floats. If you suspect zink in your lead flux with sulfur or copper sulphate (aka Zep Root Killer). Sulfur is good when you use range scraps. It will add sulphur to the lead which also acts as a catalyst for heat treating almost as good as arsenic but can be done at home. Where a respiratory with it though. Drop the heat as low as possible. Zink has a high affinity for Sulphur so it will come out of the melt for it. Down side is when it auto ignites it smells like hell and hobby rocket fuel. Which is basically what hobby rockets are made of.

Copper sulphate works by copper replacing all the zink and tin in your allow. Plus side is a super tough alloy. Down side is its Pita to cast with if the copper is too high. Which is Ironically how zink contaminated lead acts while casting. It strings and doesnt fill out well. Clogs the pour spout.

Yeah i did experiments with zink contaminated alloy and copper added alloy. Dont have scientific ammounts but my Redneck high school algebra says i srarted with .5%. At around .12% (dullited twice by 50%). Both alloys casted just fine with usable bullets. Just needes to add 2% tin and raise the pot temp to 900F. I have used up all that alloy in 9mm bullets. Kind of sadened i didnt notice any hardness increase.



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[Springfield]

Rcmaveric: .12% is not twelve percent, it is 12 one hundredths of a percent, which is almost none. Probably why you didn't have any problem with it.
FWIW, when I first started casting and smelting I used to do 3-4 hundred lbs of weights in a setting, I just dumped them all in and stirred until the lead ones melted and the zinc and steel ones floated to the top. As far as I know I never had any zinc contamination, as all the lead I melted made good bullets. I did scrap out some lead with this oatmeal in the dross, but now I know better. Just heat it up to 700-725 and flux it until is all goes back in. Pine shavings work well, with some candle wax to light if off with. Just keep at it and it WILL go back in. If not the first time, skim it and dump it in the next batch, and it will go.

[Rcmaveric]

Rcmaveric: .12% is not twelve percent, it is 12 one hundredths of a percent, which is almost none. Probably why you didn't have any problem with it..

Erm.... i never said it was 12 percent. I know .12% =.0012. Like i said, backwoods redneck high school algebra. Everyone will understand just like you did.

True sounds like an insignificant amount until you get into large amounts. A couple pennies in a 20lb pot. Couple ounces in 100lbs. Or about 6 ounces in a 300lb pot. Do your best to prevent

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[farmbif]

if it were me I'd put on my work cloths and steel toe boots, leather work gloves, grab the old hard hat and green glow vest, a stack of old buckets and go back to scrap yard.
and trade back the stuff with oatmeal on top and dig through the lead bin till I had enough good alloys to empty the mad money out of my wallet.
but me I just love digging through scrap yards and finding whatever catches my eye.

[lightman]

It sounds like you got some Zinc in your melt. If it were me I would sell that melted stuff back to the scrap yard and sort the unmelted stuff again. After sorting thousands of pounds of weights I'll tell you that it gets easier and faster. And I would definitely go back for more!

I can almost tell a Zinc weight by either looks or feel. The questionable ones get a test cut with a pair of dykes.