pot contamination

[Kcoyboy]

Thought I would ask the experts. Last yearIstarted picking up spent bullets at the range as the price of lead ect. Well I had some wheel weights in the pot and put in the range bullets. After about 20 minutes I noticed something wrong the lead had an orange hue . Normally the dirt ect comes to the top of pot when I start skimming.this didnt seem to be happening it was all an orange hue kind of mess. Also the spout was jammed so I thru the whole mess on the ground (very jingerly) I assumed copper contamination but I hear the pot would have to be 1500 degrees for that! Now Ive got some 10 pounds or so of contaminated lead with some left in the pot itself. My question is what to do to purge the contaminates from the pot ? And is this lead wasted or can I purge this also. Some of the bullets might have been copper washed would this have caused this? I remember throwing some jacketed bullets I pulled in the past and never had this problem. Any help would be appreciated.

[snaggdit]

I haven't come across orange yet myself, but the las time I melted wheel weights I had a purple hue. I, too would like to hear from the experts about what might have caused this. Didn't seem to cause any problems, though. Cast some boolits later with the ingots and they were fine.

[waksupi]

The purple would be the natural color of the lead/tin oxidation, and nothing to be concerned about. The orange has me puzzled, as I haven't come across that before. I would try running the heat up, stir it with a dry stick real thoroughly, and see what develops. I can't imagine it is copper contamination. Maybe some sort of weird sintered bullets in the mix? Felix and Sundog have some experience using copper lead alloys, and may be able to shed a bit of light.

[44man]

Metals are funny things. Antimony melts at 1166* yet will alloy into lead very nicely at 600* with a good flux.
And we all know that even an alloy with a lot of antimony in it melts at a low temperature compared to what each element needs by itself, even alloys with copper do not need more heat.
I suppose some copper could dissolve into the lead at a lower temperature then it takes to actually melt it.
Kcoyboy has now found the reason we do not smelt in the casting pot! [smilie=1:
I would put the stuff in an old cast iron pot on a stove outside and bring it to 600* and skim it good without fluxing to see what happens.
Use a thermometer and don't go above 600*.

[Lloyd Smale]

try casting some bullets with it. Its probably fine. Even if it does have a small ammount of copper in it that can be a good thing if it casts ok.

[docone31]

Surface rust in a melt can produce some interesting colours.
When I get that orange colour, I just stir, crank up the heat, stir some more and keep pouring. It will collect at the top of the mix and become slag.
It came from the wheel weights.

[Gunslinger]

:hijack:

What exactly gives by stirring with a wooden stick? Does it flux kinda like saw dust? I assume a small percentage of the stick's surface burns when you stir with it?

[docone31]

Wood carbonizes under that heat. It helps pull oxygen from the melt reduceing the slag.
When I stir with wood, I leave the carbon from the stick on the melt. It becomes charcoal and 02 goes to it before makeing oxides in the melt.
It is inexpensive also.

[DLCTEX]

It sounds as if you smelted in your bottom pour casting pot. Never smelt in the casting pot. Use a steel or cast iron pot over a burner, gas, electric, or wood , etc. to smelt and casting life will be much nicer. I also use a wooden dowel (1/2 inch) to stie and scrape the pot, and use a large spoon to scrape down the inside of the pot while full of melt, and while empty and hot. Your orange contaminate may be copper that was tumble plated onto the bullet.

[oldoak2000]

. . .orange hue . . ? Depleted Uranium . . . ! ! ! :-o Don't breath it . . . .












-Just Kiddin' . . . . . . . . . .:mrgreen:

[Gunslinger]

Wood carbonizes under that heat. It helps pull oxygen from the melt reduceing the slag.
When I stir with wood, I leave the carbon from the stick on the melt. It becomes charcoal and 02 goes to it before makeing oxides in the melt.
It is inexpensive also.

I see... sounds convenient, I'll try that out next time around.

[Kcoyboy]

Ive been casting for 15 years or so and havent seen anything like this. Always used the RCBS pro melt to melt the wheel weights and add a small amount of tin! Its always worked like a charm until this. Like I said the spout clogged and wouldnt come uncloged. Also when the lead dried you could see it was contaminated. Now there was some clay mixed with the bullets but you would expect this to float to the top like the dirt in the wheelweights!

[Down South]

I ran into some orange the other day while smelting down a several hundred pounds of WW. The orange was isolated to one spot in the pot while I was skimming off the clips and trash. I have no idea where it came from or what caused it. It was evidently some type of contamination that I let get into the pot. I also had one pot of WW that I let get contaminated with zinc, (my first). After a little experimentation, I think that I got rid of most of the zinc so that I could cast with that batch. My advice would be to cast with it and see what you get. If the batch seems to still be contaminated to the point that it won’t cast good boolits then take the advice above and bring it up to around to 600 deg. Flux it good and skim off all of the crap and see if it will cast.

[Down South]

Sorry, double post.

[Kcoyboy]

Will have to wait until it gets warm for sure. Another thing I had the heat turned all the way up but iI dont think the RCBS will heat anymore than 800 degrees . will have to buy a lead thermometer I guess. This happened last year and as I recall I kept trying to skim but every thing was all mixed together. And the spout was clogged bigtime, Even my trick with a little heat from the propane torch didnt work.

[Ole]

Thanks for the tips gents. I have been casting all day and was fighting an issue with oxidation/crap on top of my melt. I grabbed a wooden dowel to stir my beeswax in with and this tip solved my problem.

You guys rock!

Thanks again!

Matt

[Alex Hamilton]

Thought I would ask the experts. Last year I started picking up spent bullets at the range as the price of lead ect. Well I had some wheel weights in the pot and put in the range bullets. After about 20 minutes I noticed something wrong the lead had an orange hue .
What you are seeing Kcoyboy is lead oxide or litharge, which is very toxic and should be avoided.
Your alloy probably contains a lot of pure lead and, in addition, you are casting at high temperature. I remember reading somewhere that it forms at about 800F.

It really is very toxic and causes lead poisoning. It can be inhaled as airborne dust or ingested, so wear a mask and don't eat or drink anything when you are casting. Try using alloys richer in tin and antimony that melt a lower temperature, so lead oxide is not formed.

Alex

[georgeld]

One of the best things I've done was buy a Lyman lead thermometer. Sure solved a lot of my problems with wrinkles and consistancy.

Midways flux seems to build up on the steel of the pot and needle real bad. I've made a scraper, valve screw driver tool from a pc of 1/8"x 3/4" flat. Taper ground the handle end to fit the slot on the valve's needle to twist it around when it starts dripping.

The other end is bent to a 90 about an inch long and ground semi rounded with a fairly sharp edge for scraping the pot with. Don't run it hard against it, just enough to clean the crap off.

Far as purple, that's overly hot melt that's been sitting undisturbed long enough to discolor the scum and tin stuff floating on top, the melt inself should still be silver.

The only orange I've ever seen so far has been floaters discoloring as it gets hotter same as the purple is. Never seen orange colored melt so far, out of quite a few tons of scrap melt. Mostly from indoor range scrap that's had just about everything mixed in. Lots of grit that won't melt, trash, buckets full of jackets and some rocks too.

Other than a piece of loose stuff now and then I never use the pot to melt scrap in. One of the other posts has my high capacity melting pot copied after Lee's propot design. It'll hold close to 200lbs. I seldom take time to flux the big melts. Guess I should do it then to lesson the crap from ingots when casting. That's when I flux it good.

IF you can't get the valve unplugged, DO NOT try to drill it out!! Send it to Lee and let them fix it. Much cheaper that way. But, if it's old and nasty, not up to par like it should be. Include a check for half the value of new and have them rebuild it to like new condition. I'm sure happy with the rebuild they did to my old pot after I tried to drill it out and ruined things.

[leftiye]

If the orange was in the dross floating on top of the lead, I wouldn't give it a second thought. I've seen orange before, but just ignored it. I think it might be rust from iron or steel. Further, like they said above, you should try casting with it before you worry too much. I've seen zinc contamination that would cast once all the "floaties" were removed. Melt it again in a cast iron pot on a Coleman stove, flux it well, stir with a stick, skim off the junk, and give it a try. If you stir with a stick, most of that stuff down deeper in the pot will get fluxed, and float off - but still smelt in a different pot than your casting pot (or furnace)!

[JohnH]

The purple would be the natural color of the lead/tin oxidation, and nothing to be concerned about.

Not in every case. Recently my wife and I were burning some brush and once we had the pile to a manageable size, I put on my smelting pot and began to add WW, couldn't see all those wonderful BTU's going up in smoke (;)) Anyway, as we were tossing in WW I had an urgent nature call and while I was gone my sweetie kept adding to the pot, and let a peice of blue plastic get in, which she later told me about as we wondered what that pretty blue and purple hue on the melt was. It was quite interesting, as I could scrap it away and it would be replaced by a golden hue that would then begin to change into blue and purple again. This wasn't the purple of lead, a different thing that is; one will sometimes see that color in the metal itself once cooled in large ingots. This stuff, formed small "islands" or lumps on the surface of the ingots. I figured it was a contamination that would be limited to the surface in a melt, but whatever it is gave me fits when added to my casting pot. A full 90% of the boolits I cast using that metal had defects of poor fill out of the driving bands, and large porosity sites, particulary on the nose (Lee 312-185) I tried changing molds, to the Lee 452-230-TL to no avail. I then scooped out about 3 pounds of metal, drained another pound or so and then added clean WW ingots and continued casting. The problems cleared up. I have that batch of stuff seperated for a cleansing all it's own one day when I've nothing better to do.

I used to think nothing of dumping a pile of WW into the smelter and walking away while the BTU's did their thing. No more. All metal will be examined for trash before smelting.

kcoyboy, It is possible that your range has some mineral content which will produce that color at our smelting temperatures, but I'd have no real idea what it could be. If you run into someone who glazes their own pottery, ask them, as they'd have working ideas of what minerals give which colors. Not saying this is it, just a thought.