Idea to melt lead on a stove build

[Screwdriver]

So the hse guidance that any activity where heating above 500 deg C can produce fumes and is considered a high risk is wrong? (Appreciate that advice is for workplace safety and not messing around at home…)

They state quite categorically that below 500 deg C isn’t really a problem but above is.

I have seen those and the fumes they refer to are non specific. If they are suggesting “lead fumes”, i.e. lead gas then, yes, they are wrong unless the temperature is above the boiling point for lead.

 

[minimutly]

Lot of old wives tales being pedalled here as "fact". You do not generate "lead fumes" from smelting. You can generate toxic fumes from contaminants either in the lead or painted on it but the lead itself remains a solid. The only way for lead to enter the body is as particulate matter, by the time you are breathing lead fumes, you are already in some trouble since this only occurs above its boiling point (1700ºC) which is why I suggested earlier you keep it away from direct solid fuels.

So to avoid problems when handling solid lead you just have to keep it off your skin because small particles can break off and while the very smallest can penetrate skin, the biggest issue is you'll end up transporting it into your mouth next time you eat (wear gloves and wash your hands).

When burning any substance you generate ash, small particles of matter you can ingest by breathing them in. So when you are smelting lead, the mechanism for lead to enter your body is particulate, not as a gas. Those particles may be generated by contaminants in or on the lead. A mask will form an effective barrier but fume extraction and/or working outdoors is the number 1 preventative measure. A mask would not protect you from lead gas for the reasons stated earlier (and it doesn't need to).

Lead in pipes and in solder joints can contaminate water as lead forms an alloy or toxic compound and leaches into the water. When using lead solder, the fumes are again largely toxic fumes generated by flux rather than lead itslef and soldering DOES NOT generate lead gas!!

Anyhow, it is dangerous stuff to be around so if anyone is nervous, leave it alone. But so are kitchen knives, fluorescent tubes and virtually any strong acid. Knowledge about the REAL dangers and therefore the correct safe handling procedure is the key issue. Making things up or repeating debunked wives tales is not helpful.

Lead in water pipes is encapsulated, by adding tiny amounts of orthophosforic acid, turns it's surface into something else which I don't remember the name of.

 

[daleyd]

^^this really - I can’t see that it needs to be “boiling” at all for fume to be produced, and whether you class it as “lead gas” or whatever is just semantics - there’s obviously a point at which this “fume” becomes enough of an issue to be a concern. HSE suggest 500 deg C being this point, others seem to be a bit lower/higher but I think the simple fact is I would make sure the vent was as good as I could manage if doing anything with lead melting indoors.

I’m pretty sure I have a fair few off cuts kicking around the place from when we had an extension built, I might be tempted to cast a few fishing weights at some point, I got a beachcaster rod for Xmas so it might be the excuse I need to get the old bean tin out.

 

[Screwdriver]

Lead fume will be solid particles of lead carried in air. Hot enough and the liquid metal will evaporate (boiling is that temperature at which the vapour density is one atmosphere). Any liquid that is evaporated will simply change state and revert to solid - but will be able to be carried around in the air. Breathing that air will contaminate the operator with minuscule amounts of lead. That contamination is cumulative.

I sublimate bees with oxalic acid (sublimation simply means changing state from solid to gas without a liquid stage). The oxalic becomes a gas (actually a vapour) at a little over 160 degrees Celsius but soon cools to a fume (solid oxalic acid ‘fog’) and coats the internals of the beehive and its occupants. It kills varroa mites (which are parasitic on the bees), but not the bees. However it is toxic to humans so we do not breathe that fume. No different with lead or mercury - only dangerous if a person bathes, and breathes, in the contaminated atmosphere.

Fume will contain solid metal. From pure lead, it cannot be anything else but lead!

In the case of the precious metal recovery, electric arcs were used to concentrate the precious metals according to theoretical phase diagrams. Lots of fume was produced, some small fraction of which was lead. Clearly, the electric arcs were the reason for more than usual concentrations of lead in the fume.

That is some very useful and sobering information but do we agree lead fume (lit.) is only produced above 500ºC? As I have said, calling the crap that comes off melting random lead "fumes" is misleading. I may be overegging this (!) but for me, understanding the process is the important part.

If you are telling me transported particulate matter is known as "fume" then that is very good info, thanks. At least we (anyone reading this) will know not to use "lead fumes" in the vernacular. So unless you are overheating lead then your additional safety precuations, beyond those one should normally take, would be to avoid ingesting particulate matter as discussed (to death).

 

[Parm]

The expertise here knows no bounds

i Wonder how much is from real knowledge versus a few mins on Google

 

[Parm]

So the hse guidance that any activity where heating above 500 deg C can produce fumes and is considered a high risk is wrong? (Appreciate that advice is for workplace safety and not messing around at home…)

They state quite categorically that below 500 deg C isn’t really a problem but above is.

It is workplace safety but lead doesn’t have the ability to know if you are at home or work

long live the block button

 

[Screwdriver]

It is workplace safety but lead doesn’t have the ability to know if you are at home or work

long live the block button

Wassup with you now. Too much lead in your hat?

 

[gaz1]

^^this really - I can’t see that it needs to be “boiling” at all for fume to be produced, and whether you class it as “lead gas” or whatever is just semantics - there’s obviously a point at which this “fume” becomes enough of an issue to be a concern. HSE suggest 500 deg C being this point, others seem to be a bit lower/higher but I think the simple fact is I would make sure the vent was as good as I could manage if doing anything with lead melting indoors.

I’m pretty sure I have a fair few off cuts kicking around the place from when we had an extension built, I might be tempted to cast a few fishing weights at some point, I got a beachcaster rod for Xmas so it might be the excuse I need to get the old bean tin out.

just so you know you can get lead poisoning just by handerling lead

even in its roll form you can rub it when rolling it out can give you it

the old toys made from it where children used to put it into there mouth the worst way to get it

lead piping and roll form weather its used or not can give you it
its what you do after youve handled it made it shaped it

 

[Parm]

Lead is a complicated beast. easy to experience exposure, often at high levels from the simplest of tasks. It’s not to be messed with.

it’s one of the only substances that has its own set of legislation

 

[ronan]

I remember in one of Ruth Goodmans or Lucy Worsley's programmes, that you can see lead poisoning as a blue or black line across the persons gums, just below the teeth.

 

[Robotstar5]

When they built the Metro bodyshell building at Longbridge in the late 70's there was a lead loading booth at the end of the track complete with changing room and showers. It was never used so I assume legislation, HSE knowledge changed at that time?

 

[Lewis_RX8]

it’s one of the only substances that has its own set of legislation

Lead , Abestos and radioactives so specific not even covered under COSHH iirc from my health and safety assessments. Well sometimes they include pressure vessels having their own regulations as well rather that PUWER but not really a substance

 

[daleyd]

just so you know you can get lead poisoning just by handerling lead

even in its roll form you can rub it when rolling it out can give you it

the old toys made from it where children used to put it into there mouth the worst way to get it

lead piping and roll form weather its used or not can give you it
its what you do after youve handled it made it shaped it

Yes thanks I did know that (as I said earlier I do a lot of work at the only place in the world making lead fuel additives so I have to have a yearly induction detailing the dangers of lead) but that wasn’t the discussion at the time, which was about lead fumes.

 

[MCKDAVID]

The expertise here knows no bounds

i Wonder how much is from real knowledge versus a few mins on Google

always a good question on here.... hahahaahah

I have nothing to add to any of the above, except my personal experience (real knowledge not google sadly) is listed in the "silly things you've done" thread ... watch out for salt contaminated lead, has a tendancy to erupt...

 

[brightspark]

it makes me laugh sometimes someone googles something puts it on here and its word for word when you look it up

 

[Screwdriver]

it makes me laugh sometimes someone googles something puts it on here and its word for word when you look it up

Name some names.

If I want to understand a subject, I'll look it up but it is obvious to me that lead does not become a gas when you melt it, therefore it does not form lead fumes.

My amateur understanding of the dangers and subsequent questioning is rewarded when someone points out that "fume" (not "lead fumes") is not a vernacular description for the production of a lead specific gas but is a scientific term which includes particulate matter. Even so it transpires that really only occurs at elevated temperature which I point out in my first post. I also point out that particulate matter is the key issue and even without "expert" knowledge, my lucky guess is spot on even if I am not familiar with the language.

I would not profess to be an "expert" in any field which happens to have HSE requirements and if I was I wouldn't be so keen to disply deep ignorance of, say, the use of lead in hat production just to make some snarky comment about someone who dares to display some interest in their "specialist area of expertise".

I would always be wary of melting any soiled substance where you will generate toxic fumes from paints, oils or other contaminants so as I have repeatedly said - do it outside. The discussion then continues to promote lead fume as the most dangerous aspect of melting lead which is still not correct. THE most dangerous thing about lead is the much more likely possibility of ingesting it. You won't be breathing in the fumes because you're outside with a mask. therefore in response to the original question (which is why we are all here no?) is that the specific danger with lead is safe handling, keeping it off your skin and not sticking it in your mouth!

But the most important point being the answer to the origial question: should I melt lead in a pan inserted into an insulated firebox. The answer is a resounding NO. Lead will melt way below the temperature at which it will produce significant lead fume (), the heat from direct contact with solid fuel can raise that temperature to a dangerous level.

 

[Onoff]

it makes me laugh sometimes someone googles something puts it on here and its word for word when you look it up

Indeed, please people, precis, precis!

 

[daleyd]

I could be wrong but I don't think anyone has said that lead fumes are the most dangerous thing, just that there could well be the chance that you could end up breathing in something that you might not particularly want to so best to do it outside or at least somewhere well ventilated.

 

[Screwdriver]

Name some names.

Indeed, please people, precis, precis!

Yeah, I wanna know where this cut+paste from Google is...

 

[The_Yellow_Ardvark]

This weekend I was involved in lead fishing weights being cast.

The heat was from a Primus stove. The cruicble was a SS steel pot.
The lead was cut into strips and pre warmed on a 1" steel plate on another stove.
The crucible was warmed and small amount of lead was added untill a pool was formed.
The warm strips were fed in and allowed to melt in their own weight.

When there was jst over a pound of liquid lead, the cruicible was poured into a pouring flask. Yes another stove. The dross was cleaned off.
The lead then was then decanted into moulds.

Simple and fun.