Is There A Lead Doctor In The House :confused:

[350Gr]

OK here goes. I got some lead (sheet lead) from a roofing job, it had a small amount of sealant on the leading edge. I figured to hit it with a propane torch and melt into a can for further processing, this went well. All is good so far, now I put it on low heat and begin a slow melt process. When it liquified I ladled it and came out with large amounts of dross (impurities or whatever its called), this stuff was heavy but not as heavy as the lead so it came to the top. Some of this stuff looked like powder and some held together like metal, I skimmed it out, by volume it was about 15% (might have overstated that) of what I had melted.

Because I am a total novice to this and I was trying to reduce this bulky sheet lead, I only did a small amount to try this. However the lead took on a strange color hue that I am not familiar with. This lead is very soft and what I reduced scratches easily with my pinky nail. See pictures, you will note that the molded lead is still impure and also looks full of moon craters, I'd planned on refining it better later for shotgun slugs and mixing tin or antimony in with some so that I would use it for rifle bullets

I have been reading on this site lots of info in preparation for melting and casting bullets and I obviously have much more to learn. Again this was soft lead that I would have guessed to be almost pure, so I am scratching myself bald on this one.

I hope one of you "Lead Doctors" can set me straight on what is going on and what I must do to fix it.

Thanks,
350Gr

[a.squibload]

You didn`t mention fluxing, should flux before skimming impurities.
Look for threads about sawdust.
I have seen the crater problem discussed here before, can`t remember
what causes it.

Maybe that roof was hit by meteorites?

[dragonrider]

The cratering looks like you are using a teflon coated muffing pan. The one time I use one the muffins were cratered just like that. And as stated above you must flux before skimming.

[I'll Make Mine]

I agree, my non-stick coated muffin tin produces pockmarked ingots like those (though the bubble sizes seem to decrease with use, probably due to driving off some volatile component of the coating), even with well fluxed melt. They remelt well, though, and don't show any other problems when used to cast boolits. The color fringes on the top are surface oxidation due to having the metal hotter than needed when the ingot was poured; I wouldn't worry about them.

Running your smelting pot at minimum temperature to get a good melt has a couple advantages; one, it does somewhat reduce the cratering from the non-stick coating; two, it reduces those color fringes and loss of metals (change of composition) due to oxidation; three, and most importantly, it avoids gross zinc contamination by keeping the melt cool enough that zinc weights will float and be skimmed off (losing only the amount of zinc that will actually dissolve, up to about 2% by weight, which won't cause trouble) rather than melting the zinc and getting layers of zinc alloy and lead alloy.

Yes, fluxing before skimming is a Very Good Idea, but those ingots look clean enough I'd guess all you lost was some lead in the dross.

[2wheelDuke]

I agree on the fluxing when you smelt lead, I flux and stir with a wooden stick, a trick I learned here. Be careful and wear your protective gear, because wood will have a bit of moisture at first.

I wouldn't worry about the cratering, your pan was out gassing some sort of coating.

[350Gr]

Thanks everyone!

Is there something I can do to prevent the ingots from sticking to the cupcake pan till I find some good molds?

[idahoron]

Get cheep aluminum muffin pans and smoke them, They won't stick. Ron

[427smith]

When rough metaling and bullet casting I use bees wax based bullet lube for flux. couple pea sized pieces will do a 10 pound pot. just my 2 cents

[lwknight]

The cratering is the coating on the muffin pans. Burn them to red hot on the burner if you want to get rid of the pocks. I burn in all my new pan molds and still they never stick but will rust out in the elements.

You have very pure lead. Now days not all roof jacks are pure lead. They recycle whatever.
Also the flanges are soldered on so you get a bit of tin in the lead too.

[350Gr]

I got that one small muffin out and the rest stuck so hard I had to torch the pan to make'em drop out. It was not pretty! I'll burn those pans as suggested and try smoking them up. Any thing in particular you guys use for making your ingots? Seems like buying Iron muffin pans could get expensive on the front end.

Thanks for your insight!
350Gr

[runfiverun]

i made mine from some 1-1/2" angle iron.
i just cut them to length, added a piece down each side,and welded everything up from the back side.
i then dunked it into water while it was still hot and let it rust.
rust is a good release agent.
make sure you cut the sides on an angle or you won't get the ingots out.

[lwknight]

I got that one small muffin out and the rest stuck so hard I had to torch the pan to make'em drop out. It was not pretty! I'll burn those pans as suggested and try smoking them up. Any thing in particular you guys use for making your ingots? Seems like buying Iron muffin pans could get expensive on the front end.

Thanks for your insight!
350Gr

Oh OK, you used the tinned muffin pans. You need the non sticky kind. You still have to burn off all the non sticky. Tinned pans definitely will stick superbly.

[badgeredd]

I got that one small muffin out and the rest stuck so hard I had to torch the pan to make'em drop out. It was not pretty! I'll burn those pans as suggested and try smoking them up. Any thing in particular you guys use for making your ingots? Seems like buying Iron muffin pans could get expensive on the front end.

Thanks for your insight!
350Gr

Hit garage and rummage sales. It is surprising what a guy can find that would be useful for ingot molds. IMHO, aluminum should be avoided completely as the aluminum softens after repeated use and can burn through creating a dangerous situation. The aluminum pan thing has been flogged to death here for a very good reason. There are members who have been burned quite badly when the aluminum vessle gave way.

Edd

[sqlbullet]

I bought a cheap steal mini muffin pan from target or walmart, I don't remember which. The cupcake pan I used had sticking issues, and it gassed off like you see in your ingots above. The mini-muffin pan did neither. I cast several thousand of those before I switched to Lyman 1lb molds.

In fact while cleaning out my garage yesterday I came across that pan. It avoided the junk bin just becuase of how well it worked, even though I am not sure of a need for it anymore.

[I'll Make Mine]

I still don't undestand sticking in a coated pan; I've cast all my ingots to date in a single large cavity Ecko brand non-stick pan with inserted cups, and never had one stick; perhaps it's because I can melt enough at a time to fill three cups, then melt again and fill the second three before the first three are down to room temperature, and as soon as the second set are well solidified, I flip the pan and let it drop; the muffins all drop right out. Perhaps it's because the cups in mine are seamless aside from the join where they're inserted into the flat plate. Perhaps it's because I'm smelting at the lowest possible temperature (both to save fuel in the camp stove and to minimize zinc contamination if I miss a Zn wheel weight). Most likely it's some combination of the three, but I've got (so far) around fifteen muffins and have yet to have one stick -- in fact, there's no evidence that the coating in the muffin tin is even damaged, other than the bubble craters in the surface of the ingots.

[badbob454]

I agree on the fluxing when you smelt lead, I flux and stir with a wooden stick, a trick I learned here. Be careful and wear your protective gear, because wood will have a bit of moisture at first.

I wouldn't worry about the cratering, your pan was out gassing some sort of coating.

make sure the stick is dry slowly dip into the hot metal to steam out any moisture , ot it may pop hot metal out of the pot

[2wheelDuke]

make sure the stick is dry slowly dip into the hot metal to steam out any moisture , ot it may pop hot metal out of the pot

That's what I was talking about. Slowly dip the stick in, it'll boil the moisture out. But I wouldn't do that without a heavy glove on.

[350Gr]

Thanks for all the input, fellas! I did generate another question while reading your post. I have a cast aluminum pot (50's or 60's vintage).

The aluminum pan thing has been flogged to death here for a very good reason. There are members who have been burned quite badly when the aluminum vessle gave way.

Is that cast aluminum pot a no-no?

[mefunkymxw]

as long as you dont get the total temperature of the alloy and pot over 1200 F you should be ok to use cast aluminum... propane burns at 1900 so there is a possibility to melt the aluminum pot... cast iron requires over 3500 F to melt, safer if you plan to leave your burner on for hours without regulating the temperature of your lead

[R.M.]

Aluminum gets soft at casting/smelting temps. You have the chance of the pot giving way and pouring the whole thing at your feet. Not a good thing in my mind.