Author Topic: Boiling Lead (Read 1960 times)

LAREDOBOB · « **on:** April 12, 2010, 05:52:07 AM »

I was melting down some wheel weights this weekend, and I must have been in a hurry and had the fire cranked up. I noticed the molten lead was begining to boil. Is this bad, dangerous? When I poured it into the ingot mold the lead looked all grainy and dull. Did I ruin this batch or whats going on?

Sensai · « **Reply #1 on:** April 12, 2010, 07:26:20 AM »

I doubt that you were actually boiling the lead, that would be over 3000 degrees F. You probably had some impurity that was boiling off. This could be dangerous, depending on what it was. That's the reason that I do my original melting outdoors and stand upwind of the pot. Very hot lead alloy will have a grainey appearance on the surface when it cools, more like frosty. If it's really grainey in texture, you may have zinc in the mixture. Depending on who you listen to, this is either the worst thing that could possibly happen, or of little or no significence. I'm somewhere in the middle.

LAREDOBOB · « **Reply #2 on:** April 13, 2010, 04:34:58 PM »

So did it get grainy because it was too hot. It did take a loooong time to cool in the mold and was slushy quite awhile. I had some zinc weights in there but I took them out . I didn't think they would melt at this temp. How do I tell if it is zink or overheated. And is it any good. Thanks

Nobade · « **Reply #3 on:** April 14, 2010, 03:02:25 AM »

If you try to cast bullets with it and it pours like oatmeal cereal, it's got zinc in it. Zinc seems to make lead "sticky" and it won't flow smoothly or make decent bullets. If they cast normally you're just fine. Be careful to never get your lead much above the slushy temp. when melting down wheelweights, because even if you remove all the zinc weights, the steel clips are still zinc plated and that will melt off if hot enough.

Sensai · « **Reply #4 on:** April 14, 2010, 06:21:03 AM »

You can take an ingot of the suspect metal and pour a small puddle of muriatic acid on it, scratch the surface of the metal through the acid and see if it forms bubles. Lead wont bubble, zinc will. The reason that you have to scratch the metal is because just about any lead alloy will form an oxide layer, that is not very reactive, over it. You can get muriatic acid at just about any builders supply, it's the stuff that they wash masonry with to remove the excess mortar. It's not real strong, but use precautions that you would for any chemical and keep it away from metal that you don't want discolored or marred.

I have known people who cast perfectly usable and very pretty bullets with zinc in their alloys. They intentionally add it! There is a technique to it that I haven't mastered, and don't care to. It involves casting at a higher temperature and much faster than I'm comfortable with. I don't recommend it for anyone without a strong background in normal lead alloy casting. I just mention it because I hear so much about zinc being an undefeatable boogeyman. It's just another metal, neither good nor bad, just undesirable in some applications.

Dennis Eugene · « **Reply #5 on:** January 02, 2011, 08:35:45 PM »

It depends alot on how much Zink you have in your melt. Dennis Eugene

stimpylu32 · « **Reply #6 on:** January 03, 2011, 08:12:53 AM »

Quote from: LAREDOBOB on April 12, 2010, 05:52:07 AM

I was melting down some wheel weights this weekend, and I must have been in a hurry and had the fire cranked up. I noticed the molten lead was begining to boil. Is this bad, dangerous? When I poured it into the ingot mold the lead looked all grainy and dull. Did I ruin this batch or whats going on?

I would not be too worried at this point , for now your just making ingots to re-melt later , regarding the " Frosty " look , thats not uncommon with lead that has been heated too much , it will go away next time you melt it for casting , just make sure you flux well before pouring into the mold .

As for the zink , I have ran bullets with as much as 2% ( testing alloys ) and other than it being a bit harder to fill the mold , no real problems with how the bullets shot .

stimpy

pullll · « **Reply #7 on:** January 03, 2011, 09:37:24 AM »

Don't think you can actually boil lead in an open large container. Lead does boil at apox 3100 F. melts at apox 625 F. If you are using a cast iron type container it would melt at apox 2800 F. Tin and bismuth melt at a lower temp than lead, all part of wheel weights. Did you burn off the dross? A propane torch will develop apox 3600 F.

mechanic · « **Reply #8 on:** January 03, 2011, 12:08:02 PM »

Be careful...with all the warnings about lead, the zinc is far more dangerous. Inhaled zinc vapor will form sulfuric acid in the lungs resulting in permanent damage, and possibly death.

It is the source of "metal fume fever" that you may have heard of.

I lot a good friend who put zinc coated metal in a forge, then died the next day......

Ben

Land_Owner · « **Reply #9 on:** January 03, 2011, 02:41:37 PM »

I wish you would quantify how much zinc he smelted and for how long he was exposed so we don't go away with the impression that small amounts, such as would be included in a home furnace batch of wheel weights, are potentially lethal.

Is it possible he "died the next day" from something other than "metal fume fever" (like a stroke, or heart attack, or lightning strike, or run over by a bus)?

I have noticed the appearance of "boiling" within 50-75 pounds of molten lead and WW's in my pot and wondered about it too.

stimpylu32 · « **Reply #10 on:** January 03, 2011, 02:52:55 PM »

LO

They just had a show on the History Chanl. about how acid vapor works in the lungs , what happens is that the body will try to dilute the acid and you drown in your own fluids , it was what killed so many in WW1 , the Mustard Gas would produce acid and when the Dough Boys inhailed it , they were often dead by the next morning .

It does not take a large dose , however it would require a much higher % than what most home casters could produce in a normal operation .

stimpy

mechanic · « **Reply #11 on:** January 03, 2011, 04:20:18 PM »

My friend was a blacksmith, who put some zinc coated pipe flanges in the forge to hopefully melt the zinc off them. This process was probably just a few minutes, just enough to heat the zinc. The fumes formed sulfuric acid in his lungs and basically he drowned in his own fluids. There was nothing the medics could do by the time he arrived at ER. From the smelting until his death was less than 24 hrs.

The same thing can happen if you use a welder or cutting rig on galvanized.

If you are outside and away from the fumes, you are probably ok. The idea is, you have to vaporize the metal to inhale it, not just melt it.

Lead melts at less than 1/4 of it's vaporization point. I've forgotten the vaporization point of zinc, but it's far below lead.

There is alway an element of danger when you vaporize any metal. Many modern steels have components that you don't want to inhale. Just ventilate, and be careful.

IMO, when smelting lead with zinc in it, the "boiling" you see is not really metal boiling but the "nastiness" cooking away.

If you ever have a bad headache and develop a fever after smelting any metal, seek medical attention just in case.....

Also remember that metals are cumulative in the body. It takes a while for the body to rid itself of them, and if you get too much too fast, you can be in trouble.

I've smelted very large amounts of lead for years in battery repair, and so far no problems. I have become acutely aware of the hazards of metals however, and take reasonable precautions....

Ben

Lloyd Smale · « **Reply #12 on:** January 04, 2011, 01:56:28 AM »

the grainy and dull thing is no big deal but you need to be very carefull smelting lead. lead doesnt give off vapors unless you get it up around a 1000 degrees and i try to insure mine doesnt get over 800 when casting or smelting. ITs not only lead vapors you need to be conserned with. There are lots of nasty things in a bucket of ww you get from the tire store. Paper with glues. rubber zinc ect that are all nasty. Make sure you watch your temps and smelt out in the open and stay down wind.

Land_Owner · « **Reply #13 on:** January 04, 2011, 02:58:19 AM »

Quote from: mechanic on January 03, 2011, 04:20:18 PM

I've smelted very large amounts of lead for years in battery repair, and so far no problems.

Ben...I knew from reading many of your previous posts that you have been smelting for a long time without lead poisoning difficulty. That is part of the confidence factor that I take with me going forward.

Even through all of my reading, this "new wrinkle" of zinc fumes and "fume fever" was unknown to me, until you brought it up, and it made me concerned. We (my two boys and I) are outside smelting. I had thought to bring the operation into the garage. Not now.

I do not believe I am so confident as to know, without a shadow of a doubt, what is zinc in WW's and what is not. I do the best that I can though, pick out the obvious pieces, search thoroughly for it, but there are no guarantees. I will be more careful. I do not want to experience fume fever now that I know it exists and how to avoid it.

It is sad in regard to the loss of your friend.

Smokin Joe · « **Reply #14 on:** January 04, 2011, 05:23:38 AM »

Quote

Inhaled zinc vapor will form sulfuric acid in the lungs resulting in permanent damage, and possibly death.

Just to set the record straight, zinc is an element (Zn) surfuric acid is a compound (H2SO4); where does the sulpher come from?

Also, from OSHA:

"Zinc is used in large quantities in the manufacture of brass, galvanized metals, and various other alloys. Inhalation of zinc oxide fumes can occur when welding or cutting on zinc-coated metals. Exposure to these fumes is known to cause metal fume fever. Symptoms of metal fume fever are very similar to those of common influenza. They include fever (rarely exceeding 102o F), chills, nausea, dryness of the throat, cough, fatigue, and general weakness and aching of the head and body. The victim may sweat profusely for a few hours, after which the body temperature begins to return to normal. The symptoms of metal fume fever have rarely, if ever, lasted beyond 24 hours."

SHOOTALL · « **Reply #15 on:** January 04, 2011, 06:53:44 AM »

To add , old timers say drink whole milk when cutting or welding galv. pipe . I have done both for years and drink some milk when doing so and have never been effected . I have worked in some closed in places . wives tale maybe , don't know . But why take the chance ? Besides the milk is furnished free !

mechanic · « **Reply #16 on:** January 04, 2011, 11:49:28 AM »

Quote from: Smokin Joe on January 04, 2011, 05:23:38 AM

Quote
Inhaled zinc vapor will form sulfuric acid in the lungs resulting in permanent damage, and possibly death.

Just to set the record straight, zinc is an element (Zn) surfuric acid is a compound (H2SO4); where does the sulpher come from?

Also, from OSHA:

"Zinc is used in large quantities in the manufacture of brass, galvanized metals, and various other alloys. Inhalation of zinc oxide fumes can occur when welding or cutting on zinc-coated metals. Exposure to these fumes is known to cause metal fume fever. Symptoms of metal fume fever are very similar to those of common influenza. They include fever (rarely exceeding 102o F), chills, nausea, dryness of the throat, cough, fatigue, and general weakness and aching of the head and body. The victim may sweat profusely for a few hours, after which the body temperature begins to return to normal. The symptoms of metal fume fever have rarely, if ever, lasted beyond 24 hours."

It was my mistake to write sulfuric acid. The following describes what I speak of........

Most zinc salts irritate mucous membranes of the upper respiratory tract after inhalation.

a-Zinc chloride :
Inhalation of zinc chloride may cause :
-cough,
-dyspnea,
-adult respiratory distress syndrome, death, resulting from delayed pulmonary vascular fibrosis.

Ten deaths and 25 cases of non-fatal injury occurred among 70 persons exposed to high chloride concentrations of zinc chloride released from smoke generators. Of the 10 fatalities, a few died immediately or within a few hours with pulmonary edema, whereas those who survived longer developed bronchopneumonia. On dissolution of zinc chloride, both hydrocloric acid and zinc oxychloride are formed, contributing to the corrosive action

IMO a person is not at risk with adequate ventilation. My aim was just to alert folk to the possibilities. I have no fear of welding or smelting, but I do so now with an eye toward ventilation, using a fan or whatever I need to keep the fumes to a minimum. Internet research will teach a person all they need to know about the danger of certain metals. Chromium and cadmium are two others encountered by welders that can pose a danger......

Some of the danger is from the bodies reaction, (autoimmune), and may vary with the individual.

Ben

45-70.gov · « **Reply #17 on:** January 04, 2011, 12:22:16 PM »

i have had welders get sick on the job welding gavanized steel

the just kept drinking milk and welding

these guys also smoked cigarettes and had no regard for their health

i have cut galvanised steel many times and welded it some with no side effects

does any one know just how much ZINK contamination it takes to cause a problem??

SHOOTALL · « **Reply #18 on:** January 05, 2011, 01:42:17 AM »

Same here , had a welder that could smoke while welding . When I fitted galv. pipe I always burned the galv off about 4-6 inches back . BTW that welder die a couple years ago from lung and throat cancer .

Lloyd Smale · « **Reply #19 on:** January 06, 2011, 12:06:32 AM »

i have needed chelting theropy 3 times for high lead levels. Mine has been as high as 88. I know that this has come mostly from smelting. Now i do more casting and smelting then the average 3 guys do but dont think it cant happen. Anymore i dont smelt unless its outside and i keep upwind. Try not to let your pot go unattened and get up to real high temps either. ANymore with zinc wws its about a sure bet to ruin your alloy if you do anyway.

Junior1942 · « **Reply #20 on:** January 06, 2011, 01:34:56 AM »

Invest maybe $25 in a casting thermometer. When smelting wheelweights keep the crucible temp just barely above the point where lead melts. The zinc wheelweights will be floating on top of the melt. The melting point of zinc is about 100° higher than that of lead.

SHOOTALL · « **Reply #21 on:** January 06, 2011, 01:59:28 AM »

In the winter we would be in large bath rooms like schools have with the lead pot going trying to work and stay warm. Some would hold food over it to warm it up