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Brass fumes

Agnes has given us some valuable about disposing of
pickle and has alleviated my concern about copper and silver residue.
However, I did find some disturbing about heating brass.
Some of it consists of 30% or more of zinc, and the balance is
copper. I learned this from an article written by Charles Lewton
Brain, which is on the Orchid website.

I referred to the article as I had a strange occurrence in the studio
when I was annealing a 1"X6" 16 gauge strip of brass planning to
runit through the rolling mill to reduce it to 18 gauge and Suddenly
my smoke detector alarm went off. I immediately shut off the torch,
but could not detect any smell of smoke. I resumed trying to
annealthe brass, and the alarm went off again. I quenched the brass
and set it aside.

I do a lot of annealing of silver, and lately some copper as I am
using thecopper in practicing anticlastic raising. Never, had the
alarmgo off before.

For a test I took a large piece of copper, and set about annealing
it. No problem. The alarm was silent.

Obviously it was fumes from the brass that triggered it, in all
probability the zinc content. or whatever else is in it. As I had
purchased the batch of brass at a garage sale, I I did learn that
brasses are composed of different compositions, but have no idea
about the composition of the batch I go. However, after receiving the
warning from my smoke detector, I have no intention of trying to heat
the brass again.

I never use brass, but as I had these on hand thought I could do
something interesting with them. Not a good idea. Alma

There are MANY kinds of brass with a great many alloying metals,
zinc being one often used these days (cheap). There are tin,
aluminum, magnesium, and on and on brass alloys so it is pretty
important to make sure of what alloy of brass you are using if you
are planning on high temperature soldering, casting or welding. Zinc
Fever is well known in the steel welding industry, chills, and
vomiting being the primary “tells”. Not a fun to put one’s body
thru, , I know from experience.

So be sure of the alloy and if you are going to use high temperature
procedures, stay away from tin, zinc or other low temperature
alloying metals mixes. Also with these low temperature alloys, high
temperature procedures, mostly TIG or MIG welding, burns out the low
melting point alloys and the weld area and filler brome a different
color from the parent metal, as the low melting point metal has
burned off, , changing the alloy. Could be a very big issue in
jewelry, architectural work and sculpture, again I know from past,
not so good experiences.

Hope this helps someone not make a problem for themselves.

john dach

HI Alma,

I’m not sure it was zinc fumes. (something, clearly, but probably
not the zinc.)

So far as I know, zinc is only going to fume off if the metal is
either molten, or very nearly. When it does, your flame will flash
blue, and you’ll see weird electric blue smoke. (Ask me how I know
this.) (Years of casting student projects where they supply the
’bronze’. Sigh. I only twitch a little, every so aldskfjal;dfs) It
also coats the nearby area in zinc soot, which looks like white ash.


PS. > You want to see truly weird smoke? Try making niello. When you
dump the sulfur in, you get what looks for all the world like black
and blue fire. Imagine black where normal flames are red, and blue
where they’re yellow. Wild. Best seen from inside a full-face
respirator. Trust me on this.

This is why whenever I work with anything I wear a high vapor
particle mask and put up with my friends calling me Darth Vader
because I only have on set of lungs and one life.

The detector probably detects gases as well as smoke carbon monoxide

Safe is better than sorry I only buy bronze to work with that I know
the content.

Take care Alma

Brian, As you point out it was not the zinc fumes that set off my
fire alarm. But whatever it was, it got my attention, and there is
no way that I am going to be heating that brass again. Alma

Teri, You are right about the need to wear proper masks when working
in thestudio. I wear a dust mask, but need to get something that
gives better protection.

My smoke detector is only about 4 feet from where I do my torch
work, and this is the first time it ever went off. Did some
annealing of silver today, and not a peep out of it. Whatever set
itoff when I was working with the brass, must have been potent.


if Zn is the culprit, it will make very fine ZnO power that could
set off a toast detector…

try it with pure Zn and see if you get the same effect.

luckily Zn toxicity is not high - you need to get an acute dose over
repeated exposures to have real problems…

Yeah what seems to be a bargain at the time usually ends up a
nightmare in the shop when it comes to unknown alloy.

sigh I got a 4ft x 8 ft sheet of brass free but I will not be doing
any high heating I will probably do piercing and rivets and make
moving candle lanterns that throw images on the walls. If it was in
storage and not in the house that burned down. Worse than senior
moments are fire moments didn’t we just buy a. fill in the blank. oh

It was just stuff stuff is replaceable


Teri, how wise you are not to be taking chances heating the brass.
Mine seemed a bargain at the garage sale, a big pile of 18 gauge at
least 15 lbs or more, but of unknown origin. Mine cost $5 at a
garage sale. What a good idea to use it with cold connections. I will
probably make someornaments for the garden and stick to working with
silver for jewelry. Delighted to see that the price is coming down.

I just started working with bronze from RIO to make a series of
large neckpieces for a show. I also just began reading the Orchid
newsletter and came across the thread about brass and bronze fumes.
I am soldering it with acetylene/air. Should I be concerned? I do
wear a mask.


Perhaps you should replace the smoke detector with a heat detector.

Just my $0.02

Garden ornaments good idea and now that Hans has shown me how to do
blind riveting I have some ideas for clockwork items


I recently gave a workshop in cuttlebone casting, and had the
students use the casting bronze from Rio. We used the Ancient
Bronze. The smoke detector was silent, and the bronze cast
beautifully. Alma

This discussion about brass fumes reminds me of a case early in my
jewelry education. Another student moved into an old house with brass
doorknobs which were badly tarnished. She spent a lot of time
polishing them mechanically and gave herself a bad case of poisoning.
It took her a long time to recover.

So now if I’m using my dremel to polish any crud off copper, etc., I
stop and put on a mask as I can smell and feel the junk in the air.
Fortunately I’m not doing it often or for very long, and often leave
the room for a while.


Just to clear up some concerns about soldering in general and
soldering brass in particular.

ALL soldering stations should have some kind of ventilation (even an
open window with small fan pulling air out). If not the user should
wear a vapormask and clear safety glasses when soldering ANY metal.
It is flux fumes that are the most harmful and some fluxes do have a
smell. When the solder flows some trace metal fumes from the solder
only will rise and suspend for a short period of time at the moment
the solder becomes liquidus. The metal being soldered gives off no
measurable vapors unless the surface is overheated to the point of
melting or boiling the surface.

Zinc. This brass is called jewelers brass.

So a good recommendation is to know where your brass comes from and
what the metal content is. A good supplier will give you this

Fluoride free fluxing agents. These are available at most suppliers.
These are the safest fluxes but should also be used with

Grifflux #1

Links to Rio Grande’s brass sheet and wire. Metal content is

Brass is an

alloy of primarily copper and zinc. Some brass alloys may have other
metals added like lead which is found in brass alloys designed for

If you heat brass above 1665F 907C you will begin to vaporize the
zinc. Zinc vapors can cause respiratory distress and a illness
called metal fume fever if you a high enough exposure, but normally
you would need to be melting a lot of brass to get that problem. You
will not create copper fumes as the temperature for that is way too
hot for any normal torch work at -4643F 2562C.

If you are using silver solders you will not raise the temperature
of brass high enough to get zinc fumes unless you grossly overheat
the metal.

You should only use unleaded brasses for metalsmithing. These are
the C2XXX series alloys C2600 is the common brass sold by most
suppliers it is also known as Cartridge Brass, there is also C2200
Commercial Bronze, C2300 Red Brass, C2700 Yellow Brass. Avoid any of
the C3xxx series alloys as they contain lead to enhance machining.
Even in the unleaded brasses there may be enough lead to be in
violation of the strict lead laws in the US for children’s jewelry
which basiclly extends to all jewelry.

James Binnion

Thank you James for the detailed explanation about brass. I for one
will not be using the brass that I have for anything that will be
worn. As I mentioned in another post, I will be making some garden
ornaments with it, which do not require soldering. Alma