the Good, the Bad and the Ugly

[ssn vet]

Well the snow has finally melted and we had decent weather on Saturday. My wife had the kids out shopping and I finished my honey do list and got as far with my latest "home improvement" project as I was going to get......

Carpe' Diem.....let's get to smeltin'

The mice had invaded the large two burner Colmeman stove out in the shed, but after 30 min. I found where I squirreled away my single burner back pack stove....

So here's the Good...

7350

and for the Bad, the two zinc floaters....

7351

and the Ugly....

7352

Now for my question.....



After I picked the clips with needle nose pliars and skimmed off the obvious paint/grunge, I had a thin silvery layer floating on top of a charcoal gray body of fluid.

I've inquired around a bit and I'm getting conflicting info. about what this is and what to do with it....

most say it's the tin......flux the pot and stir it up and it will go back into solution.

But one gentleman, who seemed quite knowledgeable, told me that if the amount of tin is below the solubility limit, it will not come out of solution (i.e. seperate and float to the top) unless it is boiled off or chemically seperated. He believes that the silver layer floating in the pot is lead-oxide and that it should be skimmed off.

So what's a newby to do????

In this my first smelt....I forgot all about fluxing, untill the last minute, and then I quickly scrounged up some dead pine needles and stirred them into the pot with a dead hardwood stick.

It smoked and burned/charred the pine needles, but what else it did, I can't tell you.

Next two accesories for my wish list are a thermometer and a hardness tester.

till them it's empirical evidence is all I've got to go on.

[leftiye]

Sorry, I don't think there's a way (short of an analyzing machine, and a sample) to know for sure. Was the surface nice and shiny after you fluxed? Oh, I forgot - and skimmed the ashes off? Then the tin oxide had been reduced, and the tin re-integrated into the melt. Tin oxidizes at the surface and forms a grey scum on the melt. I don't know where those Knowledgeable guys get that other idea. We've seen them here too, and had our wars, and tin does oxidize, and you can reduce it back into the lead. Tin will not separate from the melt because of being lighter than lead though.

Charcoal gray melt (cooled or molten)? That could be a serious problem. Lead itself is a shiny silver color too when molten. Regardless, cast some with it. Does it cast is pretty much what's important.

[tding]

I'm seeing and hearing the same conflicting stories about the layer of grayish/silverish "crud" left on the top of the smelt after removing the obvious debris. Is it tin or is is lead oxide?

[ssn vet]

Charcoal gray

well, I'm thinking this could have been due to the lighting (I was under the tail gate of my beater 1-ton, just incase the rain came back), so it was in the shade on an overcast day....

also, the skillet was black cast iron, so maybe I was seeing the reflection of the black skillet on the surface.

[454PB]

You worry too much.

After you've smelted them down and removed the clips, raise the heat a little. From your pictures, it looks to me like the melt was not hot enough. I know everyone is zinc paranoid these days, but zinc melts at 787 degrees. It looks to me like you were around 600 degrees when you removed the clips.Give it a good fluxing, and skim off the powdery stuff on the surface. Cast a few boolits with the melt and see if they meet your standards.

[beagle]

Most of the "crud" and here I'm talking the silvery looking stuff is probably antimony or other impurities that has seperated from the alloy due to temp differential.

Of course, some of it is what you mention...pure crud. I have an old cooking spoon and I'll press it against the side of the pot and there's crud left. Black looking stuff and that's discarded.

A good fluxing will allow the alloy to combine agian and all of the crud seperate on top once the melt gets up to temp.

For sure it's not pure lead oxide. There may be some in it and I'm sure there is but most is good stuff that has seperated.

When melting shot and particullarily magnum 9s which have a high antimony content, you'll get this silver looking stuff at the top. After one fluxing, skim it off and save it for alloying pure stuff as it's high in antimony. I had a friend that used shot exclusively before it turned into gold and I'd always grab a coffee can full when I was over there as he didn't use it. Alloyed with pure leadand atouch of tin, it made great bullets.

Sundog I beleive it was wrote something on recovering lead from this stuff you mention sometime back. Maybe he'll weigh in on this subject./beagle





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I'm seeing and hearing the same conflicting stories about the layer of grayish/silverish "crud" left on the top of the smelt after removing the obvious debris. Is it tin or is is lead oxide?

[Buckshot]

...............A lead-tin-antimony solution will not weight segregate, ie: tin migrate to the top and lead at the bottom. However, due to oxygen (which is a very active element) being in contact with the surface, it will react (and heat increases the rate of reaction).

Once the oxide layer is established it forms a barrier to further reaction. This is one of the benefits of a bottom pour pot, in that this layer is (largely) not disturbed once formed. I say largely because the edge may cling to the interior of the pot to one degree or another. As the level in the pot lowers, the portion clinging to the wall will move off the surface exposing fresh metal. Ladle casting constantly disturbs the layer to a much larger extent, exposing fresh metal to oxidation each time you dip into it. This requires much more frequent fluxing.

A negative to the bottom pour is that through some action I cannot explain (surface tension on the bottom?) somehow or other powder like impurities will gather on the bottom. Best I can think of as an explaination is however it gets there, it's trapped under the lead by the lead's weight, or surface tension? Regardless the mechanics, it's there and will eventually find it's way into the valve well on the bottom.

This stuff happens with ladle casting also, but dipping from the surface means it's a non-issue, as such. In rendering down the wild scrap lead in an 8 qt cast iron pot into domesticated ingots, at the tail end of operations as the level becomes very low you will find a substantial amount of this (usually black) powder.

In any event, when fluxing your casting pot you should flux well enough that you see NO evidence of silver in the spoon you're using to remove it. If you do you haven't fluxed well enough yet.

.................Buckshot

[jcadwell]

You picked the clips out one at a time with needle nose pliers... That's commitment. I use a metal kitchen spoon with holes in it. Drop it in the pot, let it heat up so the lead doesn't stick to it, and you can get all the clips out quickly.

http://www.dkimages.com/discover/previews/744/173797.JPG

[runfiverun]

you can get them out way faster with a big ole magnet
pick them up give a little shake and dispose
i use a little metal pail, as they are hot, and just pull them off the magnet with my welding gloves.

[38 Super Auto]

I suggest fluxing before you remove the junk. If you reduce oxides of your alloy metal, especially tin, you'll be money ahead. Paraffin, sawdust, or whatever you use is cheap. You don't want to lose alloy metal when you skim.

After you have properly fluxed your alloy, you should be left with a dark sandlike powder on top.

Cheers,

[ssn vet]

thanks for the replies....

when I saw the opportunity, I jumped at it, even though I wasn't really ready....

learning by doing, ya know?

this whole fluxing thing is still kind of a mystery to me......

so that can only mean.........

time to visit Rog(er) down at the garage for more wheel weights.

having a mechanic who casts and reloads does have it's advantages ;)

maybe he'll even spot me a little ball of that marvelous Marvelux he swears by.

anybody out there ever tried that stuff.....Roger says it's great.

[John Boy]

Vet - Get that Thermometer! And only heat the melt to 650* F. Then you should have no fears that the zinc stuff has melted into your good stuff

[Alchemist]

Marvelux will start battles too. Some like it, others don't. I use it and like it cause it smokes very little, if at all. I have fluxed with bullet lube, don't lthat much smoke. Just try a few things till you find what you like best.

Alchemist

[Buckshot]

...............If I hadn't thrown my Marvelux away I'd have gladly shipped it to you. It made a mess on the walls of my furnace and it's hydroscopic. Flux with it and your fluxing spoon is plated with the stuff. Next time you go to use the fluxing spoon, the Marvelux crud has absorbed moisture out of the air. Unknowingly stick it into the lead and SURPRISE, you get a visit from the Tinsel Fairy.

................Buckshot

[ssn vet]

I have fluxed with bullet lube

That's what I tried the other night when I cast my first batch ever from this material....

I slided off ~1/4" from the lube stick, cut it in half and dropped the half moon shaped piece in?

Can you say SMOKE!!!!!!!!!!! :eek: and FIRE!!!!!! :eek:

I'm going to get kicked out of the basement if I try that maneuver again, as my wife works in the adjacent finnished office.

Going to try Ivory soap next.......and just a few chips.

[Ricochet]

You want to smell something nasty that stays around the house for days? And gives you a nasty cough to boot?

Put some boolits coated with LLA, or lube containing LLA, on your molten lead.

[Jon K]

I use lube to flux, just use a small amount that looks like a small pea. I also save old boolits w/lube and leakage from lube sizer for flux.

Jon

[bigdog454]

I use bees wax for flux, don't know if it's any better but it works. My wife got some old candles from the church and I use a small slice, (holy smoke), then ignite it to get rid of the smoke (holy flames), seems to work fine.

[targetshootr]

...............If I hadn't thrown my Marvelux away I'd have gladly shipped it to you. It made a mess on the walls of my furnace and it's hydroscopic. Buckshot

My Pro Melt was used when I got it and it had a yellowish build up inside. Is that from Marvelux? I also got a tub of leftover Marvelux in the deal but I don't use it.

[montana_charlie]

My Pro Melt was used when I got it and it had a yellowish build up inside. Is that from Marvelux?
I'm pretty certain all pots get that yellowish coating over time. It is quite different from 'rust' (which results from Marvelux).
I think it is an oxide of one of the metals in the alloy...but can't prove it.

That yellow coat is rather powdery, and I suspect it is what Buckshot referred to when he spoke of that 'something' that stays submerged and eventually causes bottom spout problems.

Whenever I have occasion to drain my casting pot, I oil that yellow stuff to prevent 'dust', and clean it out with a wire brush. After washing out the pot with gasoline (to cut the oil) and wiping it dry, I spray the interior with aerosol graphite. It seems to prevent (or retard) that yellow buildup.

In addition, fluxing with a wooden stick I carefully scrape the pot walls and bottom, using the stick as the 'tool'. I think that helps prevent the 'yellow stuff' from initially separating from the alloy...or causes it to re-combine with the alloy as a normal part of the mix.

CM

[sundog]

Preface: I am not a chemist.

One possibility is that it is sulphur. From what I have read antimony and arsenic are more common as sulphides than in their elemental form. Sulphur is that same sorta yellow color.

Here's a reference (http://www.galleries.com/minerals/byname-a.htm).

Either way, sure don't want to breath any of that dust when cleaning the pot.