bubbly ingots?

[Dustinxxx]

I smelted some lead today and poured in my muffin pan i bought.. when i got them out of the pan, they look like they had a lot of bubbles in the lead? Any suggestions?

[GLL]

Any condensation or rust in the pan? Very cold pans commonly have moisture on the surface !
Rust is actually hydrated iron oxide.
Jerry

[bumpo628]

Sounds like the pan is coated in teflon or something like that. You need to burn it off with a torch or over an open fire. I wouldn't put it on a bbq since you already poured lead in it. Once you burn it off, you'll be fine.

[John Boy]

Sounds like the pan is coated in teflon or something like that.
BINGO and probably the 'lead' was wheel weights. WW's have antimony in them and the crystalline structure ... doesn't like Teflon pans for some reason

I just experienced this using a mini muffin Teflon pan to make decoy weights

[Linstrum]

HEY!!! WHOA!!! STOP! NEVER USE TEFLON COATED STUFF AROUND MOLTEN LEAD! THE TEMPERATURE CAN BE HIGH ENOUGH TO DECOMPOSE TEFLON INTO HYDROGEN FLUORIDE GAS AND HYDROFLUORIC ACID, WHICH ARE DEADLY! SMALL AMOUNTS OF HYDROGEN FLUORIDE CAN CAUSE BLINDNESS. DON'T GO BURNING TEFLON OFF OF UTENSILS, THAT GENERATES CLOUDS OF HYDROGEN FLUORIDE GAS AND HYDROFLUORIC ACID.

See:

http://en.wikipedia.org/wiki/Hydrogen_fluoride

READ THE SECOND PARAGRAPH IN THE ARTICLE

Hydrogen fluoride poisoning via the lungs is a darned painful way to go because it causes tissue burns, plus it is one of the most metabolically toxic materials commonly encountered in the home. If anyone here has not been injured using Teflon coated equipment around molten lead, count yourself lucky. The fluorine compounds used in dental preparations are in tiny amounts, so just because it is a tooth decay preventative and dietary micronutrient doesn't mean it is safe in larger amounts.

I can't emphasize this enough, I am a chemist by education and employment, and we had to learn all this stuff about the unusual or unsuspecting ways of becoming poisoned, and there are lots of them.

rl 1037

[Dustinxxx]

ok, so are they still good to cast with? or should i melt them back down?

[Linstrum]

I'd use the ingots the way they are, just ventilate the room real good or go outside so you don't get into any residual fluorine compounds. You'll be okay as far as the quality of your boolit metal.

rl 1038

[bryonbush]

wow did now know this. ive been making my ingots with the mini muffin teflon coated tray for a while now. never noticed it smoking or discoloring though which i guess is good. (ihope).

[Mooseman]

My ingots looked bubbly ...then I realized it was because I used a cast iron "Corn Bread" pan so my corn shaped ingots Have Kernels...LOL:groner:

[mdi]

I have a "non stick" muffin pan that, when new, would leave a "bubble" finish on the ingots. I always thought it was an oil or coating from the manufacturing process as it soon burned off and I now get smooth ingots. Did not smoke nor emit toxic fumes, that I could see, but then again I didn't get my face over the filled pan...

[Linstrum]

I have a "non stick" muffin pan that, when new, would leave a "bubble" finish on the ingots. I always thought it was an oil or coating from the manufacturing process as it soon burned off and I now get smooth ingots. Did not smoke nor emit toxic fumes, that I could see, but then again I didn't get my face over the filled pan...

Hi, mdi, if you got your muffin pan just recently it is probably coated with a silicone non-stick material. Teflon is just now starting to be phased out from use on cookware and being replaced with one of the silicone elastomers. But second-hand Teflon coated cookware is going to be around for a real long time at places like the Salvation Army and Goodwill, so it isn't going away any time soon.

The simple fluorine compounds generated from decomposing Teflon are cumulative besides immediate toxins (in the same manner as lead, mercury, cadmium, etc), so just because you didn't get sick (or heaven forbid, drop dead!) right off doesn't mean you were out of harm's way.

People with small pets like hamsters and birds who overheat a Teflon pan in the home kitchen sometimes end up killing their small pets. It is like the canary in a coal mine used for detecting carbon monoxide gas, small animals have much higher rates of metabolism than us humans and will succumb to toxic materials more quickly than we will. If you have a small dog or cat that hangs out near where you prepare wheel weights or cast, keep them out of your work room so they don't accidentally get hurt or burned. Pets won't hold their breath when they smell something irritating, so if you have an accident where lots of fumes are produced they could get hurt.

Working with casting alloys itself has the POTENTIAL to be quite toxic because some of the major alloy constituents are both immediate poisons and cumulative poisons. When casting is done in the manner that produces good boolits, the temperature is not high enough to release poisonous metals that can be ingested. The most poisonous metals used in casting are lead, antimony, and arsenic. Once in awhile cadmium and mercury are found in scrap alloys, and those two are really bad. Cadmium is used in ultra-low melting point alloys, like Wood's Metal and Rose's Metal that superficially resemble lead. Because we don't always know for sure exactly what is in scrap alloy, it is a good idea to use pretty good ventilation when you have something unknown. Tin is also a major alloy constituent, but it is entirely non-toxic in its metallic form. Copper is also pretty much non-toxic as a metal. Both tin and copper are used in cookware, potable liquid handling equipment, and domestic water pipes. Lead used to be used in domestic water pipes a long time ago, but starting in the late 1960s it has been mostly removed by now.

When I prepare casting alloys I do it outside or use really good ventilation to remove from the area all the smoke and fumes from paint, rubber, and trash that are found in wheel weights so I don't breath in that stuff. I pour a little sugar on the wheel weights and set it on fire to help burn off the paint and rubber fumes, burning sugar is not as irritating as sawdust - just my personal preference. When I cast boolits from alloy that I cleaned up I only use minor ventilation unless I am using something that may be contaminated with cadmium.

When casting is done in the temperature range that produces the best results, along with keeping water out of the melt, using safety equipment for not getting burned, using safety glasses, using boolit casting alloys without cadmium or mercury, keeping the fingers out of the mouth, and hand washing, IT IS VERY SAFE.

Don't do anything to get visited by The Tinsel Fairy, and have fun!

rl 1039

[para45lda]

Never thought about using sugar to burn off contaminants. Thanks!

Wes

[fishnbob]

Thanks Linstrom, that was a real eye opener.

[Fishman]

Thanks Linstrom, that was a real eye opener.

Sure was. Maybe a sticky?

[Dan Cash]

People with small pets like hamsters and birds who overheat a Teflon pan in the home kitchen sometimes end up killing their small pets.
Wow, Linstrom, you have given me a whole new area to develop as a retirement occupation; casting room hamsters. The market should be great with opportunity for repeat business. Now, I only have to figure out how to keep the brood stock from freezing in the North Dakota winter.

[DODGEM250]

Good thing I only use my teflon coated pot for melting bullet lube.

[famdoc2892]

Thanks for the heads-up! I've not only got an explanation why my ingots are bubbly, but also a reason to be thankful I do my WW smelting outdoors!