Author Topic: Lead Removal  (Read 3116 times)

jwright

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Lead Removal
« on: September 19, 2007, 07:21:58 AM »
This has probably been posted before -- does anyone know if it is possible to get the lead traces out of cast iron so it is safe to use after having lead cast in it?  I know for a fact that quite a few of the corn stick pans have been used for casting lead ingots.  I never did it because of possible later consequences -- plus I needed the pans for cooking -- but my father-in-law gave me several corn pans that he had used for lead casting.  I hate for them to go to waste if there is a way to clean them.

Is there enough lead dust, traces, or whatever to be a hazard in the first place?  
 
Jerry W.

Offline C. B. Williams

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Re: Lead Removal
« Reply #1 on: September 19, 2007, 08:38:09 AM »
Good questions. I'm not telling anyone to do this, but , if it were me, I would cook in the pans.
Now my question. Why would anyone want pieces of lead cast in the shape of an ear of corn? Trot line weights maybe when there nothing else to use ?
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Offline Roger Barfield

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Re: Lead Removal
« Reply #2 on: September 19, 2007, 11:17:06 AM »
Jerry, I think if you electro clean them and go over them with a soft stainless wire brush, they should be fine to use.  Wouldn't the seasoning take care of any residue.  What do the chemists say?
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jwright

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Re: Lead Removal
« Reply #3 on: September 19, 2007, 11:18:58 AM »
Why lead ingots in the shape of ears of corn?  He cast his own bullets for pistol shooting and the ingots were easy to store his scrap lead -- but mainly he didn't cook cornbread and was too cheap to buy lead ingot trays.

Good question, though...   ;D

Jerry W.





jwright

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Re: Lead Removal
« Reply #4 on: September 19, 2007, 11:25:31 AM »
Roger,

You are probably right -- I imagine it takes a bit more lead than the traces which would be picked up by eating a few pieces of cornbread cooked in those pans to cause damage to anyone.  Also, the seasoning WOULD probably seal in what little was left.

My brother gnawed off a lot of the wood and lead-based paint from the baby bed he slept in while he was a baby/toddler and he doesn't seem TOO damaged.   ;D

I WOULD like to hear from the chemists and/or metallurgists, though.

Jerry W.

Steve_Stephens

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Re: Lead Removal
« Reply #5 on: September 19, 2007, 12:02:50 PM »
Someone smart in chemistry should know what acid would eat lead by not cast iron.  Maybe?

Steve

livens

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Re: Lead Removal
« Reply #6 on: September 19, 2007, 03:06:48 PM »
Im no smart, and certaintly not a chemist but I believe the Acetic acid in vinegar will dissolve lead.  read here:

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

Quote
Ancient Romans boiled soured wine in lead pots to produce a highly sweet syrup called sapa. Sapa was rich in lead acetate, a sweet substance also called sugar of lead or sugar of Saturn, which contributed to lead poisoning among the Roman aristocracy.

Of course vinegar will also dissolve iron. I used a 50/50 solution of vinegar and water to remove light rust from one of my corn molds, works great! 20 minutes or so soaking in that will not harm the iron, and could possibly dissolve trace amounts of lead.

Also I read here: " http://mysite.du.edu/~jcalvert/phys/lead.htm " this interesting passage:

Quote
There is no risk at all in handling lead metal. It cannot be absorbed through the skin or the respiratory tract. Dilute hydrochloric acid has little effect on it, so the lead would pass through the stomach before any damage was done. Eating lead is probably safe, but not encouraged. Carbonated water dissolves lead to some degree. Food and drink should never touch lead, since organic acids, such as acetic acid, may dissolve lead. Lead is, on the whole, very much less a hazard than mercury. It was made dangerous by its widespread use in paint and motor fuel, and that is now past.

It seems lead salts are much more dangerous than pure lead. But the above seems to have been written by a student so maybe not?

jwright

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Re: Lead Removal
« Reply #7 on: September 20, 2007, 10:21:16 AM »
Good grief!! And I am a gun enthusiast, too!!!

There are solvents for sale that are specifically formulated to remove copper and lead from gun bores after shooting ammunition with bullets made from either of those metals.  I would bet that a good scrubbing and soaking with some of that solvent would clear up any significant amounts of lead.

In reading about lead poisoning, it does sound like the exposure would have to be pretty significant or long-term continuing before it would affect anyone, with adults' bodies excreting 90-something percent of the lead within 24 hours -- but who knows what may be the straw that will break the camel's back...

Thanks for participating in the search.

Jerry W.

maloney108

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Re: Lead Removal
« Reply #8 on: September 20, 2007, 05:41:03 PM »
Well here's something from one of the chemists.

I checked my books and the best way to remove lead is with Nitric acid!  Now the reality is that it's very nasty stuff and not easy to get ahold of and it gives off noxious fumes - in short, not the ideal solution.  Vinegar will also dissolve lead, but not much faster than the iron, so not a good choice there either.  Interestingly, lye will oxidize lead which is then much more soluble in vinegar - but then both your baths are contaminated with lead.

I looked up one of the gun bore cleaners (Wipe-Out) and it seems to be OK, but I think there are some secret ingredients in there that they aren't telling us about. I don't think it would hurt to try a gun bore cleaner, followed by a thorough scrubbing with soapy water.  It might be abrasive, so I wouldn't use it on anything but a 'user' the first time.  One of the features of the Wipe-Out is that it turns blue if there is lead or copper present, so you clean until the wiper is not blue anymore.  I don't have any clue what it will do to cast iron, but it seems to be harmless to the steel in gun barrels.  I'm not endorsing it, but I didn't find anything that raised red flags either.

The thing about lead is that it's a cumulative poison - it just builds up in your system and never goes away, so any exposure adds to the multitude of exposures you've already had (especially if you're from the leaded gas and paint era like me!).  It won't kill you, but it's another brick in the wall. I need every brain cell I've got.  With so many cheap cast iron users around, I don't see the need to use one that's held lead.

As far as metallic lead being not toxic, tell that to the Romans.  They used lead pipes for water and the little bits that turned into salts and dissolved got to them big time!  Every time you cook with a leaded cast iron pan, you'll leach a little into the food and it will be in the form of adsorbable salts.  I think you're right, Jeremy, about a student writing it.

I had hoped I could be more definitive, but this is what I found and that's my two cents.

« Last Edit: September 20, 2007, 05:46:10 PM by maloney108 »

jwright

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Re: Lead Removal
« Reply #9 on: September 20, 2007, 10:26:59 PM »
Lots of good information, Jim.  I really appreciate getting so many different sides of each possible cure.  I'm like you -- I grew up in the A-bomb testing, lead fuel, lead water pipes, lead solder in cans, lead rings, lead necklace dangles, etc...  I had hoped it would be a more simple and positive fix -- but I have plenty of pans without using those.  I wonder if the solvent that turns blue on lead and copper could be used on newly aquired cast iron to see what the story might be with them?

Anyway -- thanks a bunch!

Jerry W.

maloney108

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Re: Lead Removal
« Reply #10 on: September 21, 2007, 02:47:55 PM »
That's not a bad idea, Jerry, especially if you are a firearms sportsman.  Those kits at the hardware store for detecting lead paint might also do the job on a cast iron piece.  I'd have to read the labels to make sure.  One type turns black slowly (that doesn't sound useful for cast iron) the other type is a swab that turns pink - this sounds more likely to succeed.