Hi All, A recent post in the “torch work” thread got me thinking that
I should upgrade from acetylene to oxy propane. Then the “propane
safety” post made me think I should redesign my line around rivets.
I work in a two-car garage that has a water heater in it.
My questions are these: Is acetylene any safer here than propane? Does
adding oxygen make it less safe? What provides the best combination
of safety and control? Would switching from acetylene to fuel+gas
really be like switching from dial-up to broadband?
I think the oxy/acet set up is superior to propane or natural gas
because it has a much hotter flame. I use a little torch setup with a
two stage oxy regulator and can control the torch flame without ever
changing the tip for all work. I do change it for melting though. I
was taught to master the flame…I believe that was the most useful
advise I rec’d…watch the color of your pieces not the solder. I
have also read that acetylene is not recommended for platinum work
because of the carbon base…On the contrary I have had nothing but
success welding platinum with the acetylene and prefer the heat
control over the propane.
The advantage propane has is a cleaner and softer flame. I suspect
is much more prevalent with jewelers because of this. The major
downfall to propane is that the gas “lays” when it is leaked. It
will seek the lowest level and does not dissipate easily. It is very
dangerous to have a propane tank inside a building.
A recent post in the "torch work" thread got me thinking that I
should upgrade from acetylene to oxy propane. Then the "propane
safety" post made me think I should redesign my line around
rivets. I work in a two-car garage that has a water heater in it.
Not to be contrary, but I have used 2 propane tanks in a
commercial building for 12 years, indoors, and if you use soap and
water mixture to check all your connections every time you connect
the tank you should not have paranoia or problems. The fire dept
comes around 2 times a year, and does make an issue of the tanks. If
your connection does not leak when you test it, it will not
spontaniously loosen.
Use your best judgement to decide whether you are committed to
thouroghly check you connections everytime, or choose to do it in a
way that makes it safe for your level of commitment. If you locate
atank outside and don’t connect without leaks, you will still have
problems, empty tank or some source of ignition. Less likely, but not
impossible.
Hi Karen, If you’re concerned about the propane, consider using the
small disposable propane tanks that contain only about one pound of
propane. I use them and replace them much more often than if I had a
larger tank, but it only takes a minute and I feel safer. I have a
regular 60lb oxygen tank, however; I’d use up the disposable oxygen
tanks in an afternoon.
Hello Karen, It sounds like you may have natural gas (NG) to your
water heater. If so, consider a NG and Oxy torch. I’ve used
acetylene and propane, and much prefer NG. A plumber can easily
install the appropriate valve and hard piping to your bench. You
still have to have the Oxygen bottle (properly secured upright)
refilled occasionally, but you don’t run out of NG. No pressurized
flammable gas. Convenient, cheap, and clean-burning.
In my post a word was left out changing the entire meaning. In my
commercial building, the fire dept comes around 2 times a year and
they do not make any mention of the 2 propane tanks I use, one for
soldering near my bench, and one that is used to heat a large
pressure cooker that I use to dewax flasks. The rest of what I said
was accurate. If you do use propane tanks, check every connection
every time you refill, and don’t break the law.
The advantage propane has is a cleaner and softer flame. I
suspect is much more prevalent with jewelers because of this. The
major downfall to propane is that the gas "lays" when it is leaked.
It will seek the lowest level and does not dissipate easily. It
is very dangerous to have a propane tank inside a building.
The difference in specific gravity (ie how heavy the gas is )
between propane and acetylene is not enough to make a huge
difference in the real world. If you have a leaky tank, hose, valve
etc. either one will blow the building sky high period end of story.
It is downright dangerous to think that just because you have
acetylene you are safer than propane. I have had both gases in my
shop and over the years. I have had many leaky acetylene tanks
delivered by the gas supplier and my propane tanks have never had a
leak. This is because the small acetylene tanks that jewelers
normally use are also used by plumbers and construction workers who
drag them all over the place in and around job sites. They get
damaged and the gas suppliers don’t bother to check the integrity of
the valves before filling and so you end up with one that has a
valve stem leak or a damaged seat for the regulator and either way
you have a leak. With the propane tank I own the tank and have that
same tank refilled and take that same tank back to the studio with
me so it is well taken care of and I have never had a leak.
No matter which fuel gas you use any time you change out tanks or
adjust fittings you must do a leak check with a leak detector fluid
(this also applies to oxygen tanks and fittings)and inspect your
hoses. If you follow this rule you will be very unlikely to have any
problems with your torch setup.
As for the warning label on propane tanks about having them indoors
that was mentioned in the first post. The reason it is there is
because the tanks are sold to consumers and it is to limit the
liability of the tank manufacturer. As professionals we are supposed
to know of the safety precautions required for our equipment. If
you have an acetylene tank in your home studio and the place blows
up you can bet the insurance company will have a similar reaction
about your liability for the damage to your house. If you are going
to have a torch setup in your house be sure to let your insurance
agent know so that you can get the proper coverage. If you are in a
commercial building then your business insurance agent should know
about all your equipment. If you are running a studio without proper
insurance then don’t be surprised if you are required to pay for the
damages in an accident.
It sounds like you may have natural gas (NG) to your water
heater. If so, consider a NG and Oxy torch.
The other nice part about Natural Gas is that it is lighter, not
heavier, than air. With propane, you end up with a cloud of propane
that accumulates near the floor. Natural Gas accumulates near the
ceiling and goes down. This is why houses tend to be piped for
natural gas instead of propane – overall it’s safer.
The problem is that NG is not always available in the kind of
pressure that you want for torches. I’m not sure if this is a
problem for jewelery usage – this usually is a problem for
scientific glassworkers and neon benders, where they’ve got burners
that are pretty huge – for example, a ribbon of flame 24 inches long
and 2 inches wide.
My questions are these: Is acetylene any safer here than propane?
Does adding oxygen make it less safe?
Acetylene when ignited explodes; propane deflagarates, or burns
rapidly (flashover). In short, propane in “large quantities” can be
impressive, too, but acetylene will do a lot more damage if a tank
leaks. If your oxygen tank were also leaking, it’ll make either gas
burn more rapidly and violently. If properly maintained, the odds
of both a fuel tank and oxygen tank leaking simultaneously are
remote. If you can make propane work, ( I do. In fact, I’ve never
used acetylene for my gold and silver), I say use it instead.
In my post a word was left out changing the entire
meaning. In my commercial building, the fire dept comes around 2
times a year and they do not make any mention of the 2 propane
tanks I use, one for soldering near my bench, and one that is used
to heat a large pressure cooker that I use to dewax flasks.
This is a “your mileage will vary” by locality type thing. I live
in an area where apartment dwellers get cited regularly for having
20lb propane tanks on balcony decks (because to get them there you
have to take them through the interior of the building). Some fire
marshals have more stringent standards than others. There is a
distinct difference between the city and county inspectors locally,
for example.
Ron Charlotte -- Gainesville, FL
@Ron_Charlotte1 OR afn03234@afn.org
Natural gas and oxygen WILL work for most jewelry repairs and
manufacturing … the problem is with the street pressure. It is
generally less than 7 lbs. This is sufficient – but it can be hard
to get the heat you need for larger sterling pieces. (Larger than
say 1 1/2" square) It is also difficult to melt for pouring ingots
and castings. Mind you, I said difficult – not impossible. My
partner for 30 years used natural gas and oxygen exclusively for
EVERYTHING! Including casting and ingots, and welding platinum –
but he would spend 10 minutes waiting for the larger stuff to get up
to heat.
I started with propane/oxygen and prefer it – having tried every
combination available. We have 4 different fuel setups, with 5
different brands of torches for students to try.
As to getting a plumber to install a line for you, I don’t know
anyone I could recommend that travels over in your area. Shouldn’t
be a big problem though. Most any licensed plumber can give you a
bid on installing an extra service line. They generally take care of
the permits and arrange the inspection, just make sure it gets done.
If you are not making large sterling pieces this is the safest,
easiest to insure method.
Frei- Borel has always been great with me, I think that perhaps
there might have been an assumption on their part that you knew a
bit more about what you were trying to accomplish than you might’ve.
Talk to 'em some more. You’ll find someone there that will help you
with your problems. The Meco Midget has been my favorite all around
torch for over 30 years. Once you get everything right you’ll love
it too…
Leaks and explosions are really not common. My point was simply that
there are ways to cut down on the already infinitesimal odds, and
make reasonably sure that your insurance will be there if/when you
need it…
Brian
P.S. There are devices available that will increase the street
pressure, but the prices are still prohibitive for the average small
studio. Look into 'em just so you understand what is available. If
you need to know where to look, I think that Blaine Lewis at New
Approach School is using one of these units … maybe he’ll post the
site address again?
I am compelled to make a comment about the use of disposable propane
cylinders. In addition to be a costly form of flammable gas, the
spent cylinders are becoming a waste management nightmare. (Reasons
too lengthy to go into here.)
This is a plea to use refillable tanks and reduce the number of
disposables. Thanks for your consideration,
Judy in Kansas, who serves on the county solid waste management
committee and has a passion for recycling.
the problem is with the street pressure. It is generally less than 7
lbs.
To be specific. Natural Gas is delivered to homes at less than 1/2
psi after the regulator at the meter. Commercial Accounts can run a 2
psi line inside the building or even 5 psi in some cases.
A lot of what is available will depend on the pipeline that is
supplying your area. I have seen a house that they tapped on to the
TEPPCO (Texas Eastern Panhandle Pipeline) in the ground out front,
and used a regulator to drop the 60 psi down to 1/2 psi, but that is
unusual. I even saw them arc weld a saddle to the working pipeline
and drill into it to make the tap! It can be done if proper
procedures are followed.
What you need all depends on the torch and the amount of heat
required by your work. Most smaller work should be doable with
household pressures.
I service and repair gas lines and equipment to several million
btu’s and once silver soldered copper lines used for Hydrogen Heat
Treat Furnaces for engine blocks.
It is downright dangerous to think that just because
you have acetylene you are safer than propane. I have had both
gases in my shop and over the years. I have had many leaky
acetylene tanks delivered by the gas supplier and my propane tanks
have never had a leak. This is because the small acetylene tanks
that jewelers normally use are also used by plumbers and
construction workers who drag them all over the place in and around
job sites. They get damaged and the gas suppliers don't bother to
check the integrity of the valves before filling and so you end up
with one that has a valve stem leak or a damaged seat for the
regulator and either way you have a leak.
JIm, this is great in formation. Suddenly, I find my self in
situation where I suspect one of the acetylene tanks has a leaky
valve. Unfortunately, I am using a studio that is part of City Rec &
Parks, and I am not an employee nor do I have any authority over the
studio. I was working late (alone in the studio) and suspected the
new tank was leaking. This was confirmed by applying leak test
solution. I was unable to reach the supplier so I called the Fire
Dept for advice. They sent a crew and tightened down one of the
connections and said the tank was no longer leaking. The next week
the instruction said the tank was not leaking. A few day later I
hauled the tanks out and discovered the same problem the line would
not bleed on the new tank. It appears that excessive force is
needed to close the valve. I retested the tank when open and found
no apparent leak. What is the problem? Is this tank safe to use?
I feel that the tank should be replaced.
The valve stems and seats as well as the coupling threads and mating
surfaces on the small acetylene tanks take a lot of abuse. If you
have a leaking one call the gas supplier and have them swap it out.
They should do this at no charge as it is their responsibility to
provide a tank in good working condition…
Have you checked the hoses? It is a good idea to replace the hoses
on your tanks about every three years, depending on use. I thought
I had a leaky tank in the basement of my house. I was using
aceytelene. I checked, and re-checked, no problem with the tanks.
Most puzzling. Then I realized that my cat had chomped through the
hose. There were these nice little punctures where the gas was
leaking through.
Hoses crack and get leaky as well. Schools for Adult Ed and Parks
and Rec places are notorius for bad hoses.
I have a question about torches: I was taught at school (using an
oxy/propane mix) that the rule for safety is Propane, then light,
then add oxygen. For turning off the torch, the reverse - oxygen then
propane - is true.
Recently, I started a welding course at Central Tech, and the
teacher was adamant the Rule used by all gas welders is “A before O,
or up you go” (A=Acetylene, O=Oxygen). He further said the same rule
applies when using Propane, and that the reason is that the oxygen
’blows out’ any chance of the lit propane travelling back down the
pipe.
Can anyone please explain to me why jewellers use the reverse
process from welders? I’ve searched the internet, and all I can find
are disparate answers on the procedure, but nowhere can i find the
reason why jewellers would use the reverse procedure for the same
gas/oxygen mix when turning off the torch? IS there a reason? The
closest I’ve come to is “otherwise you get a nasty ‘pop’ sound”.
You should do it the way your welding teacher said. The chances of
gas burning back up the hose is remote with little jewelry torches
but you still don’t want gas burning as the torch goes out. Oxygen
doesn’t burn but it aids in combustion so if you turn your gas off
first the oxygen pushes out any flame and is a clean method. Burning
gas alone is dirty. I was taught you want that pop. That pop is
atmospheric pressure returning to the tip. When I light my big
casting torch I actually turn on a little oxygen then also so it
starts with a blue flame and you don’t get the blackbirds floating
around your shop from dirty had burning. Hope that helps.