Back to Ganoksin | FAQ | Contact

Acetylene torch

    I guess that means all-electric buildings are safer??   As far
as igniting gases, an all electric building is not really safer. 
The most obvious culprit is the switch which turns on your
refrigerator's motor and air compressor from time to time and makes
a spark when it does so.  The contacts on your electric water
heater may also spark, as may your thermostat and furnace blower. 
Any light switch will unless it's a mercury switch.  

You may have read about the incident recently in NYC where two
brownstones were destroyed, evidently because of a faulty gas dryer.
The couple returned home and called a neighbor to come over to
investigate a gas smell and they all went up together, evidently when
someone touched a switch. The fire department said the whole house
must have been full of gas. Yes, propane, being heavier than air,
will tend to pool and is probably more dangerous, but the other
gases, mixing with air in a closed space, can also be lethal.

I’m not sure what the final answer to this problem is. Certainly if
you can keep your tanks small and if you can keep them in their own
enclosed space, that might help, but an enclosure only concentrates
the gases, so, unless it is bombproof, it isn’t much help. I guess
that natural gas might be a bit safer than the tanks. Most people I
know use a 20 lb. propane tank, and that, at least, could be put in
some outbuilding when not in use. You also could have it only half
filled to cut down on the amount of combustible. There are lots of
places to refill. All that said, my oxyacetylene rig sits in my
living room next to the jeweler’s bench. It is a small tank, so I
guess I won’t have a chance of taking the neighbors with me.


    Not necessarily if the tank connections leak.  It is safer to
transport, though.  An oxygen cylinder under pressure can become a
deadly missile if it tips over and the valve is broken off.
Therefore, chain your tanks to something that isn't likely to tip

So can an acetolene bottle - it (they) will become just like a
torpedo. Or so I was instructed.

Just a thought . . . those who make lamped beads have large
propane/oxy tanks in their home studios ( in basements and kitchens.)
Some of these people also do silversmithing , using acetylene, in the
same area. Now, using that example, I think I am much safer keeping
just an acetylene B tank in my basement.

The person to whom I am referring has been inspected by the fire
marshal in the area, and no citations were given. Maybe different
areas have different rules . . .

that little accident with burning holes in my lines after laying them
on a freshly soldered piece ,which caused a major leak in both
lines…no explosion…Thank the gods…has caused me to install
flashback arresters…much earlier this year I had posted how my tanks
are set up to help control gas build up from leaks. My bench is set up
in front of a window…The tanks are mounted in a box outside with an
exhaust fan installed in the bottom of the box, pulling any gas
leaking out and away from my area…the lines run in through the
window , controls accessable through the window which can be shut when
the tanks are not in use…took a very short time to install but
seems to work…

Acetylene and propane are both very dangerous gases to be treated
with great respect. Propane BBQ tanks should never be taken indoors.
Propane is stored under pressure. A propane tank has a pressure
relief valve on it that will open if a full, and cool propane tank is
taken indoors and allowed to warm up. This valve will open releasing
large quantities of propane into your house. Acetylene is not stored
under pressure. Rather it is disolved in acetone. This is because it
becomes unstable under high pressure. It also has a relief system that
works somewhat differently and will not open simply from warming up.
If you search the Orchid archives, (Search my last name "Fischbein"
and under teh subject of “Propane again” you will find a few Orchid
notes that I wrote a few years ago that describe the relief
mechanisims on these two gases in great detail.

Propane is heavier than air and will pool, but BOTH GASSES ARE JUST

I do not have acetylene in my home. I use propane, but only in the
small cylinders used for plumbing torches (I believe that they are
less than one pound). My philosophy is that the less of these gasses
I have in my house, the less chance there is of a serious

Acetylene can be used safely if used and stored properly, but I
prefer not to have it in my home.

I am an mature jeweller, but a full time engineer, working in the oil
and gas industry and have designed the industrial facilities for
storing, shipping propane.

Milt Fischbein P.Eng
Milt Fischbein – @mfisch1


You’ve mostly got it right, though a bit overstated Re: the propane
danger. A light switch won’t generally do the trick, since the gas
will be usually at floor level, and most light switches don’t generate
a spark. And for what it’s worth, propane accidents are quite rare.
But they CAN, and now and then, DO happen, and then it’s not nice. As
you note, propane is a heavy gas. And dense. So it sinks to floor
level with a leak. I small leak isn’t a problem, since as with any
gas leak, it does dissipate. But it dissipates somewhat slower than
most fuel gases, and fumes/gas levels at the floor level can
accumulate more than at, say, nose level, where it’s more easily
noticed. Now, if there’s a leak where you’re working, never fear,
you’ll smell it at nose level long before it’s even remotely
dangerous. And in most rooms of a house, especially if there is air
conditioning or forced air heating, air circulation is enough to
prevent “pooling”. the dangerous situations come when propane manages
to leak into, usually, basement or crawl spaces. These often are not
ventilated as well, so the gas isn’t as easily dispersed or disturbed
by air currents. And what else do we have in basements? Right.
Furnaces, and water heaters. And if gas fired, these have pilot
lights. Where? At floor level. If propane levels can build up to an
ignitable concentration at the floor level, then these pilot lights
can set it off. Now, for most basements, it should be noted that this
is not a small amount of propane from a slow leak. It’s gonna take a
fairly substantial leak, for quite a while. Like leaving your torch
valves wide open, but forgetting to light it, then leaving the
workroom for an hour or two while you go tend the yard… Or maybe an
outright broken regulator or tank valve. But if that happens, then
your house becomes quite unlivable really dramatically. And the leaky
tank does not always even have to be in the basement itself. Many
houses, especially older ones, have cold air return vents in various
rooms, where cold air sinks back down to the basement, to be again
heated by the furnace. Such a floor level opening to the basement
can allow propane leaking in an upstairs room, to gain adequate access
to the basement space to cause a problem.

The bottom line here is that propane fueled exploding houses are
rare, and getting to that point takes a relatively major problem in
the tank setup before you go boom. But nevertheless, it CAN happen,
somewhat more easily than similar sorts of accidents with other fuel
gases. It’s about the same as having a gas fired oven in the kitchen,
the old types without safety valves, such that if you close the doors
and windows, turn on the gas with the oven door open, light the stove
pilot but not the oven, and then leave the room sealed, eventually
your kitchen will go boom too. Now lots of folks have accidentally
left an oven or stove burner on without blowing up the kitchen. but
every now and then… Propane accidents are rare. But they can
happen. the level of risk depends quite a bit on your exact setup,
the layout of your house, the condition of your equipment, and how
careful/paranoid you are about how you use your equipment.

I, for one, have a barbecue type propane tank in my basement
workshop. It’s a reasonably well ventilated workshop, the water
heater is electric, not gas, and I’m quite careful with my tanks.
Plus, it’s just me. No children to fool with things. I don’t feel
there is a problem there. But for some people, propane will not be an
intelligent choice. heck, for some folks, any sort of torch in the
house may be unwise (grin…).

With acetylene, there are a couple major differences. Like propane,
acetylene is contained in the bottle as a liquid. (Propane is
actually liquified, while acetylene is in solution in acetone). The
tank pressures are relatively low, and thus safe (as compared to
oxygen tanks, which require quite careful handling). But the tanks
themselves are tall and narrow, like oxygen. So though the tanks are
reasonably safe, they still must be secured, either to a cart, or
chained in place, so they cannot tip, etc. Propane tanks are more
stable, just based on their low squat shape, so need less restraint
or bother in the setup. The main difference safety wise between the
two is that acetylene gas has a quite small molecule, and the gas is
light, and dissipates quite rapidly in air. Plus, like propane, it is
manufactured with an added odor, so that it’s quite noticeable when
there is acetylene in the air from a leak. Because it dissipates
quickly, leaks are noticed quickly. And because it dissipates, rather
than sinking to the floor, it is much harder to get enough of a
concentration from a leak to be explosive. In a small closed room,
it can be done. But you need much more gas to leak, and the room must
be more tightly sealed. All in all, it’s very unlikely that this
would happen.

As a fuel gas for jewelry work, acetylene is also quite different
from propane. Acetylene is, to put it simply a really dirty gas.
Burned without enough oxygen, it sends little bits of soot flying all
over the room. makes a mess. Burned with enough oxygen, it’s a very
very hot flame, sometimes too hot for some types of work. You get
around that by using smaller torch tips, and for many tasks, this is
just fine. But you cannot, for example, get as good results with
platinum work using acetylene, since the excess carbon in even a
slightly oxidizing flame can cause problems with the platinum. Small
torches with acetylene work fine for general small work in gold, but
working silver with acetylene and oxygen can be a bit more difficult
than with gasses like propane or natural gas, which burn cleaner, let
you use a gentler larger flame if you like, and generally are more
suited to working cleanly.

If ALL you want to work with is silver, especially general
fabrication work, the acetylene may well be a very good choice, since
the air/acetylene torches like the Smith handi heat or the prestolite
type torches, produce a very nice flame that’s well suited to silver
work. Quite different than the flames from oxy/acetylene equipment.

You should also be aware that you have other quite viable options as
well. Although natural gas is more familiar to us coming from the gas
company, and residential gas lines are usually not high enough gas
pressure to run a torch well, you can also get natural gas in
compressed tanks, looking quite like the oxygen tanks. Natural gas is
a very fine fuel gas for jewelry work, much like propane, but it’s a
lighter gas, and does not present the specific risks that propane
does. MAPP gas is a mixture of gasses, presenting some of the best
of both acetylene and propane, in a form that also is much safer than
propane alone, and without either the overly high temps or the mess of
acetylene. It can be burned either with air, much like acetylene in a
prestolite torch, or with oxygen. Both MAPP and bottled natural gas
will cost more to run than propane, and maybe even acetylene. But
both work quite well, and some folks like one or another quite well.
If I could not feel OK with the propane tank in my basement, I’d be
using bottled natural gas, rather than acetylene and oxygen, though I
do have an acetylene B tank running a Smith handi heat, in addition
to my more frequently used torches. Like I said, it’s one of the best
torches for silver fabrication.

By the way, on the subject of tank safety. one often overlooked topic
is the oxygen tank. In my view, the oxygen tank represents a greater
risk than a propane tank ever would. With the gas tanks, you must
leak enough gas to form a flammable mix before anything can happen.
With oxygen, any leak increases oxygen levels, and if this occurs to
more than a minor degree, then any combustion in the room will be
accelerated. More important is the fact that a newly filled oxygen
tank is filled to a pressure of about one ton per square inch. think
about what happens if you accidentally drop such a tank in a way that
breaks off the neck/valve of the tank. If you open a gap in the top
of the tank of a square inch in area, then you’ve created a rocket
motor with a ton of thrust in the other direction. The risk is if you
tip over a full oxy tank, and hit the valve, cracking it
significantly. The pressure completes the job, blowing the valve off,
and the tank then accelerates VERY quickly, with a very great amount
of force. Tanks in that condition can knock down walls and fly
surprisingly large distances, and generally cause a great deal of
damage. And since there is usually a human involved in dropping or
knocking the tank over, if that hapless soul happens to be on the
wrong side of the tank when it takes off, it can easily kill. Even
normal use of the tank when it’s properly chained in place so it
cannot fall over, can be dangerous. The regulator, on it’s high
pressure side, where the adjustment knob is, is holding back a very
high pressure gas. If the regulator is faulty, then it’s possible for
it to burst from the pressure. Flying parts can be moving fast enough
to cause injury. The adjustment knob or T bar itself can be shot out
fast enough to take out an eye or worse. And if some idiot is dumb
enough to try and oil an oxygen regulator that seems sticky, the oil,
exposed to high pressure oxygen, can spontaneously combust or explode,
again destroying the regulator, and potentially causing a great deal
of damage to anyone close by. And for what it’s worth, I know of more
accidents cause by oxygen tanks than propane tanks. Think about it.
That oxy tank, when full, represents an enormous amount of pressure
and energy that can be instantly lethal if the wrong things happen at
the wrong moment.

Now that I’ve scared you about the oxy tank, sit back and relax.
Because the truth of the matter is that properly used oxygen tanks are
generally safe enough, and accidents with them are quite rare.
nevertheless, they DO happen, now and then, just as propane accidents
happen now and then. In most cases, the accidents are the result of
negligence, ignorance or carelessness, and are preventable by proper
maintenance, proper procedures in the use of the equipment, and
reasonably prudent attitudes. If you want to use a propane tank, you
need to be aware of the possible dangers, and make the decision
intelligently. And if you set one up and use it, you need to do so
with the care and respect required of any potentially dangerous piece
of equipment. I know many jewelers who’ve set up propane tanks. I
have never heard of any actual jeweler who’s had a problem/accident
with it, though we’ve all heard generic horror stories about what
MIGHT happen, or may have happened once to someone who we’ve heard
about, but somehow nobody actually knows who this victim really is…
While a due respect for propane is needed, don’t automatically go with
the knee jerk reaction of “OH my ghod, this is much too dangerous”.
It doesn’t have to be.

Peter Rowe

Peter, Thank you for such a comprehensive writing on pros and cons
and safety of various gasses! Would you consider writing something
on the subject of regulators? I understand the basics but would
appreciate a better understanding of adjusting them as well as any
caveats. I use acetylene but I’m sure there would be interest on
regulators for other gasses as well. Thank you for your valuable input to the forum!
Susan Ronan

    never be brought into the house. Geo. 

Guys, there has to be some exercise of reason here about this topic.
I have been using acetylene (oxy-acet, actually) for 30 years. I have
had multiple tanks of acetylene in: my bedroom in my parent’s house,
all four apartments I lived in and both houses I have owned. I have
also had them in a garage-like workshop for five years and in my
retail store for almost 20 years. There is no difference between
having it in your house or a workspace. If you exercise a little bit
of common sense about it you won’t have any problems. If you check
your connections thoroughly each time you set up a new tank and try
not to be too drunk when you are soldering so that you don’t burn up
your hoses you will not have a problem. Once again, let’s pose a
question heRe: How many of you on Orchid have actually had an
acetylene tank explode? No second hand info here–just your own
experience. Daniel R. Spirer, GG Spirer Somes Jewelers 1794
Massachusetts Ave. Cambridge, MA 02140 @spirersomes

I have an acetylene B tank down in my basement that I use for my
silver. I had decided to purchase the whole set up because that is
what I first leaned on in my class. In another school that used oxy
propane, but had a hard time with the flame – constantly burned all
my fine bezel wires. I went to a welding supply company and asked
tons of safety questions about acetylene and was told that acetylene
is a light gas and would seek the highest point in your house (the
attic) and get out. I had a major concern with the oxy propane
because I knew propane seeks the lowest point ( years ago a couple
in my old neighborhood were blown to smithereens because they had
stored several of their propane bbq tanks in their basement for the
winter and when their furnace went on…you get the picture)! I
was also told by one of my instructors that it certain towns do not
allow you to have that combo in your house – she uses it and doesn’t
tell them. Anyway, last week I was mentioning this thread to some
friends at my gem and mineral club. Several friends, one a welder by
trade, almost died when I told him the welding store told me the gas
was light. They told me it was the heaviest gas, was dangerous, and
if I did not have a fan blowing around while I soldered, I could get
killed with the gas! Seems this gas is pretty unforgiving, you lose
conscious and…the end! They also said that the reason I was having
such terrible problems with firescale was because of the acetyling (I
make Pripps Flux by the gallon!). They all said to get rid of it and
hook up to my natural gas line. I do not know who to believe any
more. All I know is that ALL gas has the potential of being
dangerous if not handled properly, and for the time being, with big
safety precautions, I am still using acetylene. ~Elle

HI. peter of what size of propane tanks are you considering could
represent real danger do you include the small portable tanks to
the list.? Marco.

While I did send a personal response to Mr. Spirer I wanted to clear
my image with Orchid…I was not drunk and don’t drink and resent the
suggestion that I would work around dangerous tools in this
condition. I was however overworked and possibly too tired. I think
an apology would be in order. Lisa

I have to jump in here. It is currently illegal to transport any
high pressure compressed gas cylinder without a proper DOT approved
valve cover. Keep this in mind. All these tanks can be dramatically
dangerous. The only safe way to handle them is to keep them secured
at all times. And when they are transported, remove the hose
connection and install the cover.


For the commercial jeweler the preferred fuel gasses are, Natural
gas, Propane and Hydrogen. I am not aware of any large Manufacturing
jewelers who would even consider using acetylene as a fuel gas. The
traditional acetylene torch is a holdover from an earlier time. I
happen to prefer Propane to natural gas, but have little difficulty
switching from one to the other, and am able to work Platinum with
ether. If safety or zoning requirements are a big concern I would
suggest having a natural gas line brought in by a plumber, IF you are
familiar with piping and local building codes this is something that
you could undertake yourself. Propane can also be piped in from an
outside storage tank, which reduces the risk of using this gas.

Wayne M Schenk

Elle: If you have “city gas” available to you, I think there is none
better for jewelry use. My bias is based on 34 years of many sorts of
metalwork in many different environments, with many different gas
sources. In bygone days city gas was often generated in each city, at
a gasworks, where they heated bituminous coal in an airless space:
the result was “coal gas” and coke. Nowadays, natural gas pipelines
go everywhere there are concentrations of people. I’ve used
air-propane, air-acetylene, oxy-butane, oxy-propane, oxy-acetylene,
and air-natural gas. I’ve seen oxy-natural gas in use, and it seemed
even better than air-natural gas. I haven’t had the option of using
natural gas in over 20 years, but would switch back were they to run
a pipeline near me. It’s also one of the most cost-effective home
heating fuels, if not the most cost effective.

Jim Small
Small Wonders

   So can an acetolene bottle - it (they) will become just like a
torpedo. Or so I was instructed. 

No, not really, so long as the acetylene does not ignite. The
acetylene tanks are filled with acetone liquid, in which the acetylene
gas is dissolved, under some pressure, but not all that much
(somewhat analagous to the carbond dioxide in a soda). Only about 200
pounds or so (read the regulator. It tells you) While a neck breaking
off an acetylene tank does release that pressure all in one place,
this only supplies at most, that 200 psi thrust. Very different than
the pressures in an oxy bottle, which are easily ten times that.
Plus, because the pressurized gas is in solution, with only a small
gas space in the tank, the actual amount of free gas to rush suddenly
from a broken tank is minimal. Not enough to really propel the tank
anywhere. The gas in solution does come out quickly, but not quickly
enough to turn the tank into a rocket. Of course, acetylene is highly
flammable. The release of a large amount of it, even if the tank
doesn’t go anywhere, is anything but safe. Ignition of a large tank
leakage like that could easily be lethally disasterous. And even
without ignition, you’d also then get liquid acetone all over the
place too. Not a good thing either.

Hope this helps.
Peter Rowe

I’ve had an acetylene B tank in my home (basement) studio for more
than twenty years with no problem. When I asked the owner of the
welding and gas supply shop about it, he asked if I planed to throw it
into the fire or out the window.


Mr. Spirer and all,

I saw the effects of an uncontrolled acetylene fire about twenty-five
years ago in my former life, working for General Motors. A metal
finisher had what he called a “hose fire”, where the flame starts to
burn upward along the inside of the hose towards the tank. The
torches were designed to be left burning, almost like a pilot light,
and a flip of the switch on the handle fed oxygen and increased the
acetylene flow to a preset level, giving instant use without the need
to ignite and adjust the controls.

The flame reached the regulator, resulted in a minor explosion, but
flames reached the ceiling in this huge automotive plant, hundreds of
feet in the air. The plant fire department blew out the flame using
compressed nitrogen extinguishers, and they slowly moved the
oxy-acetylene set out of doors. The gas would self-ignite every fifty
feet or so, requiring them to put out the flames over and over. No
injuries, thank goodness, but several areas of the overhead iron
supports needed replacement.

I understood afterward that reverse flow valves were defective, and
yes, I have had acetylene in my business for twenty-one years, but I
also have a compressed nitrogen extinguisher located on the wall next
to where the tanks are chained. I am not afraid of the gas, just very
respectful of it.


   No, not really, so long as the acetylene does not ignite.  The
acetylene tanks are filled with acetone liquid, in which the
acetylene  gas is dissolved, under some pressure, but not all that
much  (somewhat analagous to the carbon dioxide in a soda)...Plus,
because the pressurized gas is in solution, with only a small gas
space in the tank, the actual amount of free gas to rush suddenly
from a broken tank is minimal.  Not enough to really propel the tank

i’m going crazy! i keep changing my mind about what kind of torch to
buy. i read one message in the thread and decide (for me, a
beginner) “propane only.” then i read another message and think:
“no, acetylene only.” the only thing i haven’t changed my mind about
is not using oxy until i get more experience.

i see that an old kingsley north catalog has both the prest-o-lite
acetylene torch for a “b” tank and a propane torch for disposable
tanks. both have several size tips.

i had been leaning toward propane because i had read that propane
burned cleaner and was more stable than acetylene. but i wonder why
my jewelry instructor had suggested the prest-o-lite for beginners (he
has moved out of state, so i can’t ask him. are you out there on
orchid, don campbell?). do you think he suggested the acetylene
because acetylene gets hotter and without oxygen i might need the
extra heat? because i’ll use up the propane in the disposable tank
too quickly compared to the “b” tank? because he didn’t know there
was a propane only torch with tips a jeweler could use? something

i hope i’m not beating a dead horse, but the safety issues make me

green jean

I have worked in the Skilled Trades for most all of my adult life ( 30
Years ) and I have seen only 1 incident of a Acetylene tank burning.
( I did not cause this accident )

FLAMES SHOOTING 20 + FEET IN THE AIR will cause you to find
something else to do. I put 2 shiploads of heavy machinery between
myself and the burning tank - Some one else, with more to
prove than I did, put out the flames with a BIG BIG Carbon Dioxide
fire extinguisher - I have 2 fire Extenguishers in my house and
intend to get a larger one still.

The accident was caused by hot pieces of metal burning open the hose
and regulator of the acetylene half of a Oxy - Acetylene rig. This
caused the tank to over heat and the rupture disk to open up. These
were the large size tanks used in industral settings. Big BIG

This accident was caused by careless and negalance. I was more
frightned by the prospect of the Oxygen tank bursting and exploding
due to over pressure

I have had small leaks caused by dropping sharp hot metal on to Oxy
Acetelene hoses. These caused small flames and were easly
controlled. I keep my hoses in good repair and replace them when old

Just make sure you can quickly and completely turn off the
regulators. My Prestolite torch and regulator turns off with a small
wrench. This wrench is attached by a chain to the regulator , never to
part company…


Use Your head or have Your friends read Your name in the papers !!!

ROBB - Yes - I am a Believer !!!


well, i didn’t think of myself as a timid person before the issue of
fuel gasses, but i think i will go back to drawing and painting! no,
i have toxic solvents in painting, i’ll go back to drawing… with
charcoal… with a respirator.

Jean Adkins