SS vs. cast iron for casting ingots?

[caspian]

ok, so I am planning on smelting Pb, Sb, Tn into muffin tins for easy use in my Lyman pot. However, when cleaning the slag from my scrap lead using my cast iron pot on a propane burner, I am getting a lot of rust from the bottom of the cast iron.

My question is, should I use a stainless pot to do the final mixture of Pb, Sb, Tn for the muffin tins. I will be doing it outdoors with a respirator on to be safe and can keep wind to a minimal. I know SS loses heat much quicker than cast iron, but aside from the heat loss, is there a reason not to use SS? I want to minimize slag.

Thanks
Caspian

[AlHunt]

ok, so I am planning on smelting Pb, Sb, Tn into muffin tins for easy use in my Lyman pot. However, when cleaning the slag from my scrap lead using my cast iron pot on a propane burner, I am getting a lot of rust from the bottom of the cast iron.

My question is, should I use a stainless pot to do the final mixture of Pb, Sb, Tn for the muffin tins. I will be doing it outdoors with a respirator on to be safe and can keep wind to a minimal. I know SS loses heat much quicker than cast iron, but aside from the heat loss, is there a reason not to use SS? I want to minimize slag.

Thanks
Caspian

Why not just clean the cast iron of rust? You could get some Evap-O-Rust, pour it in the pan, cover it with cloth and saran wrap so it doesn't evaporate and let it soak a day. Maybe put the whole pot in a plastic bag while it's working.

I know of no reason not to use the stainless.

[45-70 Chevroner]

Slag is a normal thing no mater what you melt it in. If you have rust in a pot it will rise to the top of the melt, you can then skim it off. Just be sure flux the lead mixture to get all the slag out. Check the stickies to find out how to do it.

[William Yanda]

Vaporized lead IS a hazard. Lead melts at less than 800 degrees Fahrenheit. I am sure the temperature required for molecules of lead to jump free of the surface of the melt is much higher. A quick search suggests that the boiling point of lead is over 3000 deg. F. Just as you wouldn't worry about steam at the melting point of water, don't be concerned about vaporized lead at less than 800 deg. F.
Reasonable precautions are logical. Extreme concerns are nonsensical. Avoid noxious fumes. Don't eat while handling lead. Wash thoroughly after handling lead. You, and your household will be fine.

[kevin c]

I have it from somebody who works in heavy metal toxicology that the risk of lead being taken into the body from the type of lead processing we do is not from inhaling vaporized lead from the melt, but from what gets carried on smoke particles coming from materials burning off the metal. So the smoke from paint, glue, labels, oil, wax and sawdust is best avoided. Stand upwind at least. Even better use a respirator. If you can't smell the smoke while wearing it, that's good. If your processing the lead doesn't produce visible smoke your risk is probably smaller,

My propane tank pot is stored out of doors and gets rusty inside. Once the lead all melts the rust floats to the top along with any ash when I scrape down the bottom and sides of the pot and I skim it out with any unreduced oxides, even though using a bottom pour ladle means I likely won't get any in the ingot mold anyway.

I'm thinking, compared to cast iron, using steel gets you more capacity for the external dimensions of the pot, comparable strength with less risk of cracking, with less weight, at lower cost, but with less heat retention.

ETA: welcome to Cast Boolits!

[mdi]

Reasonable precautions are logical. Extreme concerns are nonsensical. Avoid noxious fumes. Don't eat while handling lead. Wash thoroughly after handling lead. You, and your household will be fine.
Finally! A common sense, 100% true answer.

[onelight]

I believe a large part of any threat to us is the lead that often oxidizes on the outside as a white dusty substance if you handle this it becomes airborne and will get on clothes and hands in mouth and lungs . If I handle lead like this I rinse with a hose + soap in a well ventilated area this will help keep it from becoming air borne and washup when I am done. This was part of the training for dealing with lead cable and sleeves at the phone Co.
Just make sure all is dry before dropping in a pot of melted metal , I have not had a problem with wet in a cold pot it will dry before it melts .

[Wayne Smith]

The most dangerous form of lead for us is white lead oxide - yea, the stuff on old boolits. It is absorbed directly through the skin. When you see white lead make sure you wear gloves.

[JonB_in_Glencoe]

I use a SS soup pot (4 qt) for smelting scrap lead. I think SS is the way to go :)

[onelight]

Take a wire brush to the rust and start melting as has been pointed out any left will float to the top and can be skimmed off after fluxing.

[45-70 Chevroner]

Vaporized lead IS a hazard. Lead melts at less than 800 degrees Fahrenheit. I am sure the temperature required for molecules of lead to jump free of the surface of the melt is much higher. A quick search suggests that the boiling point of lead is over 3000 deg. F. Just as you wouldn't worry about steam at the melting point of water, don't be concerned about vaporized lead at less than 800 deg. F.
Reasonable precautions are logical. Extreme concerns are nonsensical. Avoid noxious fumes. Don't eat while handling lead. Wash thoroughly after handling lead. You, and your household will be fine.

Actually, you won't have a problem even at a 1000 degrees. Like you said, vaporization doesn't occur until 3000 + degrees. Of course also like you said 800 or a little less is an optimal casting temperature.

[GregLaROCHE]

If I didn’t already have a Dutch oven that serves my needs, I would be looking in thrift shops for an old stainless pressure cooker pot.

[mdi]

Nearly all metals work , except aluminum. I once made a pot out of 6" black iron pipe...

[Walks]

I too cast outdoors, I use an oscillating behind me when I cast using an electric furnace or blend alloy in a cast iron pot over a big propane burner.
I have the "Lead Check" test added in with my STD blood test every year. Always comes back normal.

STS steel pot, no way. CAST IRON Forever !!!!

[onelight]

The random stuff that finds its way into the pot when melting scrap and ww and flux is more toxic than a pot of melted lead .

[Conditor22]

Stainless steel is safer than (if not as efficient as) cast iron. Cast iron can fail/crack.
https://i.imgur.com/USsWQNj.jpg

I use a large SS turkey frier for smelting large/bulky loads like pipe vents and lead pipe and sheeting

170# lead pipe vents sourced from local roofers
https://i.imgur.com/d8S4MmD.jpg

My favorite and go to smelting pot is a cut propane tank. A friend made this for me adding a large ring around the base for stability with "vents" bent in it to allow heat up the sides
https://i.imgur.com/1pwONkm.jpg
https://i.imgur.com/AS1F8HE.jpg

I used to use aluminum (because I had one until one day I didn't :) glad I didn't get hurt. For me, it's a big NO to using aluminum
https://i.imgur.com/TO8DDf2.jpghttps://i.imgur.com/455hfsA.jpg

[mdi]

Thread drift got away from casting ingots to melting pots (me too!). I use a few different ingot molds; a seamless, stamped sheet steel muffin pan, an aluminum corn bread mold, and a small loaf pan. Once reading in an old text on casting, the author mentioned the buffalo hunters often just dug a small depression in the dirt and poured their lead into that...

[lightman]

Either cast iron or stainless will work. Just remember that cast iron can crack if you start heating it too quickly and that it can also fail when its hot if you bang on it too hard. If you choose stainless make sure that its stainless and not those pots that have aluminum laminated between the stainless.

[David2011]

Actually, you won't have a problem even at a 1000 degrees. Like you said, vaporization doesn't occur until 3000 + degrees. Of course also like you said 800 or a little less is an optimal casting temperature.

The boiling point is 3000 degrees. The vapor pressure point is around 1150 degrees F but will vary depending on the alloy. Lead, like water, makes vapors well below its boiling point.

[Frosty Boolit]

That iron seems to hold moisture and has spat back at me before so I set it on top of the pot to dry it first now. If I see white powder on the lead, I spray light oil on it to keep it from getting airborne, also the oil doesn't evaporate.

[richhodg66]

The random stuff that finds its way into the pot when melting scrap and ww and flux is more toxic than a pot of melted lead .

I believe this as well. Lots of grease and oil on old wheel weights and range scrap always has some old bullet lube, etc.

I;ve been rendering down range scrap outside over a wood fire and usually pour a little used oil in the pot to get it burning and help melt and flux lead out of the jackets, but I'm out in the sticks, far from the house and I stay out of the smoke, I wouldn't advise doing it if you have neighbors.

[fredj338]

My cast iron dutch oven gets put away with about 1" of alloy in the bottom. I dont see any rust when melting new alloy. I do store it in the garage though.