Getting scrap lead clean- very clean...

[anachronism]

I was given a few buckets of range scrap a few months back, and I must say it is probably even dirtier than used wheelweights. I melted down a bucket of it, fluxed it several times, and I still feel the lead is dirty. I melted it down using my fish cooker & a cast pot, fluxed it then poured ingots. When I use this lead in the pot, it still seems filthy. like I could flux all day long & still not get it clean. There's even a little sediment in the bottom of the pot at times. Any suggestions? It must pe possible to get the lead cleaner than this.

[daschnoz]

I had the same thing with some lead I recovered from sealed lead acid batteries (never again). As I "cooked" it longer in my pouring pot, more **** floated to the top. I looked at the round balls that I was casting and they have some impurities mixed into the casting. It's not a big deal for me since those balls will be first time out paper punchers. Cook longer, and flux.

Some guys have reported good results using sawdust as a fluxing agent. Someone mentioned pipe tobacco. I was enjoying a cig while casting (I know, another no-no), so I tried the last bit of tobacco at the end of the smoke. That is when a lot of the **** in the pot started floating to the top.

[cbrick]

I had the same thing with some lead I recovered from sealed lead acid batteries (never again). As I "cooked" it longer in my pouring pot, more **** floated to the top. I looked at the round balls that I was casting and they have some impurities mixed into the casting. It's not a big deal for me since those balls will be first time out paper punchers. Cook longer, and flux.

Some guys have reported good results using sawdust as a fluxing agent. Someone mentioned pipe tobacco. I was enjoying a cig while casting (I know, another no-no), so I tried the last bit of tobacco at the end of the smoke. That is when a lot of the **** in the pot started floating to the top.

From "Linstrum" on the Castboolits forum - Maintenance free/low maintenance batteries use calcium metal-doped lead to catalyze the hydrogen gas. The lead alloy used in batteries also contains a bit of antimony and arsenic to help harden and strengthen the lead. When hydrogen comes in contact with arsenic and antimony, the hydrogen reacts to form ammonia analogues called arsine and stibine, AsH3 and SbH3. In World War One the Germans experimented with these as war gases. As such they were highly effective since they are deadly in amounts too small to easily detect.

Batteries are a huge no-no, glad you and any others in the area survived.

Pipe tobacco sounds a little pricey but for as long as I've been casting and as many different things I've tried as flux I've never had anything work as well as plain ole saw dust.

Rick

[fredj338]

You could wash the range scrap, but it will have to dry in the sun for several days & even then, you'll have to be really careful about getting any water into the melt. Sawdus ot a mix of sawdust & old bullet lube works great, especially stirred in w/ a wooden painter stick. It may take several fluxings, but the metal will come clean.

[Russel Nash]

I start up my dutch oven cold with wet or damp range scrap. This range scrap is from my range's bowling pin pit, so there are lots of wooden splinters and plastic pieces in with it.

Oh, yeah, there is lots of sand in with it too.

Not to bore ya'll with all the small details, but...when it does finally come to pouring ingots, I use a Rowell ladle. I also use a yellow pine 2X2 to get the melt spinning around and around pretty fast. When all the gunk collects in the middle, then I pick that off with a large slotted kitchen spoon.

It works pretty well.

I had stopped by my club the other day and noticed how all the lead has filled back up in the pit. I guess I will have to go harvest it soon. :mrgreen:

[lylejb]

when I first started casting, I was having the same trouble getting clean ingots. I stired, I fluxed with wax, I stired with a paint stick, I tried sawdust, I tried beeswax, I even tried fluxing with high temp lithium grease. None of it really helped much.

In my case, the cast iron pot I was using was "rough" inside, not smooth like the bottom of a frying pan. This roughness allowed the crud a place to stick, and it wouldn't float to the top to be skimmed.

My answer to this was a thrift store stainless pot, with a flat bottom. I then ground a flat side on my slotted spoon (also stainless) so I can positivly scrape the bottom and sides of the pot.

Last weekend I remelted my ingots made from the iron pot. The differance is night and day. I couldn't believe how much more junk came out of these ingots. You can visibly see the differance in color between the old and new.

It also seems to separate better at lower temperatures. When I was using the cast iron pot, it was on a turkey fryer turned most of the way up. I now use a smaller propane burner. It is slower, but I get better results. I now pour ingots just slightly hotter than melt temp.

I mostly use parafin to flux.

Hope this helps.

[rob45]

It also seems to separate better at lower temperatures. When I was using the cast iron pot, it was on a turkey fryer turned most of the way up. I now use a smaller propane burner. It is slower, but I get better results. I now pour ingots just slightly hotter than melt temp.

Actually, this is something that does deserve attention.

Most people, particularly when dealing with range lead, like to crank up the heat, figuring it will speed up the process. Range lead always has other material that absorbs the heat, such as jackets, wood chips, dirt, etc. This makes it take longer for the lead to reach melting temperature. So people crank that burner up.

The problem is noticed whenever all the jackets, etc. are skimmed out and it is time to flux and pour.

Any liquid which has heat dispersed through it will also have thermal currents. The hotter the liquid, the greater the thermal current. Although the impurities are supposed to float to the top of the lead, they can be forced to the sides and bottom of the pot, and even remain suspended in the melt.
This is why whenever we flux, we should also be scraping the sides and bottom of the pot, not merely "stirring". The scraping action helps to dislodge the sediment in hopes that it can rise to the top for easy removal, but if the currents are strong enough it may simply be suspended in the melt without actually making it to the surface. Besides scraping and fluxing, the best thing we can do to remove impurities is to minimize (we can't totally eliminate it) the thermal current effect, and that is best accomplished by keeping the heat no higher than necessary.

The concept of thermal current can be noticed while boiling a pot of water on the stove. As the water slowly comes up to temperature, we can actually see the current under the surface, and that's even before the top begins to bubble.
We cannot see it happen with lead, but rest assured it is still occurring just the same.

Just think, all this time we thought temperature wasn't important when making ingots.

[Ervin]

Go to any search engine and type in Vitaflux. Last time I looked, was less than $6 per stick for 12 sticks. One stick will flux 2000 lbs. Used by old linotype printers.

[anachronism]

My scrap is from an indoor range, and has one little ingredient you don't get in the great outdoors. Gunpowder granules. Most loads don't burn 100% of the powder, especially handgun loads. There is always a small amount that usually get melted into inert particles that look a lot like sand. I get plenty of this & it's most likely my problem. It's perfectly safe, but really tough to remove for some reason. I don't know why, it's considerably lighter than lead. I've been bead blasting my smelting pot, then rinsing it before using, to remove any residual glass beads.

[WHITETAIL]

Thanks, I will try the new pot.;-)