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Convert, Acetylene to Propane


#1
 Propane (small camping bottles) you buy by the six pack from
Wal-mart along with a regulator you can get from Stuller will be the
most economical fuel you can use.  It's much cleaner than acetylene
and cheaper that piped natural gas' monthly service fee.  

I currently have a Little Torch and acetylene/oxygen. I have natural
gas piped into the house, so I could switch to that, but I understand
the pressure is low. Can I use a 20 LB canister of propane with the
regulator and tips I currently have for the acetylene? Or what would
I need to do to convert to propane/oxygen?

TIA,
Roy


#2

I have gone through this fairly recently, so let me share what I have
found. In effect, you need do nothing to “convert” to either propane
or natural gas. Just hook it up. You won’t be able to use the
smallest (#1) tip with propane, but that usually is no problem. I
could not get a straight answer from Smith, the makers of the Little
Torch, about the use of natural gas at low pressures until after I
had already installed my propane setup. Since, they have said that
the torch will work fine at 3 or 4 ounces of pressure typical in
residential gas installations. Just reduce the pressure of the
oxygen. I have not tried it, however. Because of insurance reasons,
I located my 20# propane canister outside, in an approved location,
and ran pipe to my bench location. I had a plumber do this, with a
building permit to satisfy the insurance company. I have a friend, a
full-time jeweler, who keeps his 20# cylinder under his bench. He
has had no problems doing this, but I like mine outside!

Your acetylene regulator should work just fine, but will require some
conversion or adapters to allow it to attach to the propane canister.
I found that it was cheaper to buy an inexpensive single-stage
regulator with a pressure guage and variable pressure setting. Many
recommendations are for a more expensive 2-stage regulator, however.
Either way-converting the old regulator or buying a new, inexpensive
regulator-would have cost me about $20, so I bought the new
regulator.

Now I am glad I decided to use propane, because I am installing a
second torch which will not use “house gas” at such low pressure.
At some point in the future, I might try the natural gas option, just
to see how well it works.

Good luck!


#3
 I currently have a Little Torch and acetylene/oxygen.  I have
natural gas piped into the house, so I could switch to that, but I
understand the pressure is low.  Can I use a 20 LB canister of
propane with the regulator and tips I currently have for the
acetylene?  Or what would I need to do to convert to propane/oxygen? 

Hi Roy, I’m using the same setup with the 20 LB propane tank. Yes you
can use the same regulator as you do for acetylene. You will not be
able to use your #1 and #2 tips, they will not even light. If you have
a rosebud melting tip you will need to change that to one for propane.
I find that I use the #7 tip most, but that is just because of the
type of work that I do.

Timothy A. Hansen


#4

Oops, to answer your question completely, to switch to propane you
only need to get a propane tank ( your acetelyne regulator will hold
propane pressures. You may need an adaptor (available at a welding
supplier) and adjust tip sizes to compensate for temperature changes. Cary


#5

There is no problem using the gas that comes into your house. In
most cases it comes into your home at the right pressure. The thing
you want to do is get a “check valve” to make sure the flame doesn’t
go back down the line and blow things up. You can get them at home
centers or jewelers supply. It is a safety must.

Steve Ramsdell


#6

I just went through this with helping a friend get set up. We went to
our local welding supplier where I had bougth my Little Torch for use
with propane and oxygen. There we learned that one may use propane or
acetelyene interchangeably with oxygen and the Little Torch. The key
is the regulator for the gas side. If you have an acetelyene regulator
it will stand the pressure inherent in either acetelyene or propane
and may be used with either. A propane regulator may not be used with
acetelyene. The oxygen side is the same with either set up. I now have
two Little Torches, one propane and one acetelyne ( I bought out a
jeweler and a part of the shop was the acetelyne unit). I thought I
might use it if I need more heat but haven’t used it yet. In the past
I was started on natural gas and feel that propane is closer to that.
Anyone that is introduced on acetelyne may be uncomfortable switching
over to another gas. I think we all want things “to stay the same” and
are reluctant to embrace change. Choosing torches and fuels stretch
this idea to the ultimate limit. Availability,cost and past experience
pose so many variables that we must ultimately serve our own needs. I
have also used mapp gas and found it cleaner than acetelyne. In our
area it is more expensive and didn’t provide a benefit as I was using
it- however I would not tell someone not to use it! The varibles will
not go away! Cary


#7

If you use an actelyne torch with LP (propane) be sure to check that
the hoses are rated for LP. It takes a more expensive set of hoses to
be rated for Lp and Acet. than Acet. alone. I think it is a "T"
rating vs “R”

Dan Wellman


#8

In addition to my jeweler’s torches I also have a large shop torch
(aceteleyne) that I’ve had for thirty years. Shortly after I got it I
had to have the handpiece rebuilt. The repairman told me that I had
been the cause of the damage. He showed me the scorched components
and asked me if I turned off the gas first. Then he told me that if
you turn off the oxygen first the flame will suck back into the tip
and do damage inside the handpiece and even cause an explosion. When
one turns off the gas first the flame is pushed away from the tip by
the oxygen still coming out and extuinguishes itself-there is no flame
to draw back in. I am not saying not to get the check valve, but
turning off the gas first at the very least prevents carbon build up
inside the handpiece and may prevent more serious
problems. Cary


#9
    There is no problem using the gas that comes into your house. 
In most cases it comes into your home at the right pressure. 

I disagree with this statement, I tired it. There was less than 1/2
lb. line presure from the street and my torches “Lil Torch” and
another unknown brand, would barely produce a flame and no heat to
speak of. I am able to use the large LP gas tank “in my yard” but had
to install another slightly different regulator for the shop use at a
Y before the regulator to the house.

The thing you want to do is get a "check valve" to make sure the
flame doesn't go back down the line and blow things up.  You can get
them at home centers or jewelers supply.  It is a safety must. 

I do agree with this - every system should have the ‘check valves’.

Lorri Ferguson


#10

A word in praise of Welding Supply Companies. I’ve found them to be
helpful in the extreme.

I must be their worst customer, maybe four tanks of acetylene and
oxygen a year. They probably make about $20 per annum from me. Yet
they’ll spend ages changing my regulators over, telling me to be safe
(and delighting in telling me the most horrific accident stories) When
they got me a little torch I think the whole workshop was involved in
trying it out and making sure I knew how to do the safety checks and
the shut off procedures.

Mind you - this is Key West and wd e do rather like to look after each
other here.

Tony Konrath
Gold and Stone
tony@goldandstone.com
www.goldandstone.com


#11

With the Little Torch, which is where this tread started, the hoses
are rated for LP. If some other torch is being used, you are
absolutely right! However, (and this I do NOT recommend!) a friend
of mine accidentally rolled his bench chair over his hoses, and
severly mangled them. In a pinch, he hooked them up with clear
aquarium tubing. These are definately not rated at all, but they
have worked for him for the past several years, even though he
KNOWS he should replace them!


#12
        There is no problem using the gas that comes into your
house. In most cases it comes into your home at the right pressure. I
disagree with this statement, I tired it.  There was less than 1/2
lb. line pressure from the street and my torches  "Lil Torch" and 

I’ll wade in on this one, too! :wink: I just had a natural gas line
connected for my studio. The guy from the gas company was a bit
skeptical about whether there would be enough pressure. The regulator
at the house steps the pressure down to two pounds from “ten inches”.
I tried to get him to explain the pounds to inches, but he just said
those are the two standard measures. He said if the pressure was
indeed insufficient, they could rebuild the contraption at the house
and run full pressure to the studio. Evidently something they’ll do
upon request!

Haven’t adapted the torch fitting yet, so I haven’t tried it.

For what it’s worth,

Dave
Dave Sebaste
Sebaste Studio and
Carolina Artisans’ Gallery
Charlotte, NC (USA)
dave@sebaste.com mailto:dave@sebaste.com
http://www.CarolinaArtisans.com


#13

I may be very wrong about this. I have always used natural gas and
oxygen. I was taught and trained many people on lighting and
extinguishing a torch. We always light the gas first then apply the
oxy. When putting the torch out we turn the oxy off first then the
gas. If not you get a little bang that could indicate a kick back
down the line. The books I have read agree with this too. I would
like to hear more about this basic step and it’s safety. The term we
used was gas on first and off last. Thanks

Steve Ramsdell


#14

Hello Dave, I should have clarified my comments. I used to teach
jewelry making and lapidary. In Chicago Illinois there was plenty of
pressure.We ran a Bunsen burner, 2 Hoke torches and a larger casting
torch. Sometimes all were working at the same time. In central
Illinois, I run a soldering torch, casting torch, and burner in my
shop. I also use a hot plate and heat the shop with natural gas. The
only thing, I think, could cause trouble is the little torch has such
small diameter hoses. I am not telling anyone to do this (the
disclaimer of responsibility part), I am just stating what I have
done. All my lines were installed by professionals.


#15

Most residential and light commercial gas service is at 1/2 psi or
less. Anything over that can damage the gas valves for your furnace
etc. A loose standard is 2 psi or 5 psi in bigger commercial
services. The inches he referred to are inches of water column. (in
w.c. or "wc) and it is a physical measure of how far the pressure
pushes a column of water in a U Tube manometer. To get a higher
pressure inside the house it would require tapping off before the main
regulator or changing it and adding another to control the rest of the
house or building. If anyone has more specific questions about this
e-mail me at @Dan_Wellman and I will share what I know.


#16

oops! i guess i have a question. cary said, “The repairman told me
…that if you turn off the oxygen first the flame will suck back
into the tip and do damage inside the handpiece and even cause an
explosion. When one turns off the gas first the flame is pushed away
from the tip by the oxygen still coming out and extinguishes itself –
there is no flame to draw back in.” i was taught “goog:” gas on,
oxygen on, oxygen off, gas off. well, actually i was taught "poop."
propane on, oxygen on, oxygen off, propane off. (i was first shown a
propane-oxy torch.) i guess i generalized that it would be the same
for acetylene. is it different for acetylene? what do the rest of
you do?

thanks,
jean adkins


#17
    ...The guy from the gas company was a bit skeptical about
whether there would be enough pressure. The regulator at the house
steps the pressure down to two pounds from "ten inches". I tried to
get him to explain the pounds to inches, but he just said those are
the two standard measures. 

G’day; I had to jump in on this one too! The pressure measurement
"two pounds" means that the gas exerts a pressure of two pounds per
square inch. The pressure given as ‘ten inches’ means the pressure in
the gas line will hold up ten inches of water.

Thus; if you took a long glass tube and bent it into a U then half
filled it with water, the water height would be equal on both limbs.
Then if you were to attach the gas line to one of the limbs, the
height of water in that limb would fall and the water in the other
would rise. If you took a ruler and measured the distance between the
two heights, and it happened to be ten inches or twenty five
centimetres then the pressure in that gas line could be recorded as
ten inches of water gauge pressure. So low gas pressures are
generally measured in terms of water gauge pressure, which is more
accurate than pounds per square inch in that case…

‘The guy from the gas company’ obviously didn’t know his terms or his
job. The gas piped to domestic premises is always at a low
pressure; the greater the pressure the greater is the potential for
loss due to leaks, and most gas appliances need only a few inches of
water gauge pressure to work properly Cheers, –

John Burgess; @John_Burgess2 of Mapua Nelson NZ


#18

I get that little pop almost everytime I turn off my torches…this
is on both my torch that is only acetylene and the one that is hooked
up to both oxygen and acetylene. Nothing adverse has happened, so I
assumed (perhaps incorrectly) that this pop was normal. Is it? Is
this dangerous in any way?


#19

In response to questions on torches using Smith Equipment.

Smith has a web site…www.smithequipment.com. On the web site
they have an area where you can post questions, and have a smith
expert answer them.

I have a Smith “Silver Smith Torch” and had numerous questions. I
called Smith and they were able to answer questions as well as
sending me a technical packet.

I won’t go into numerous details, but the instruction manual for the
little torch indicates the sequence of how the gases should be turned
on and turned off. I also found it interesting that certain tips
work better with certain gases.

There was also a post on Natural Gas and pressure required. A quote
from the instruction manual is… “CAUTION: When using natural
gas, a minimum of 1 pound of pressure is required. Higher pressures
are necessary for use with melting tips.”

Wishing colorful days:
Carol M.


#20

Metalgirl,

   I get that little pop almost everytime I turn off my
torches.....this is on both my torch that is only acetylene and the
one that is hooked up to both oxygen and acetylene.  Nothing adverse
has happened, so I assumed (perhaps incorrectly) that this pop was
normal.  Is it?  Is this dangerous in any way? 

Somewhat dangerous, yes. The problem is that there is an explosion
occurring in the end of your torch, due to the fuel/air mixture
burning back into it. Most torches don’t have a whole lot of space
inside them where both gasses are present, by design, but it is
unlikely to improve the mechanism to have even small explosions inside
it.

The sequence is important because if oxygen is allowed to flow into
the torch first, then fuel is added, the mixture is highly flammable.
A small explosion could easily turn into a large one. This is why the
fuel is always turned on first, and left on til last, so that there is
insufficient oxygen present to react with all of it at once.

Loren
http://www.golden-knots.com/
lorenzo@intnet.net @Loren_S_Damewood1