I recently pulled out my portable Victor O/A torch after several years
and went to the welding supply store for some new bottles. When I got
home, I couldn't hook up the new acetylene bottle because it had
damaged threads. I took just the bottle back to the store and
exchanged it, but on the way home it tipped over. Before hooking it
up, I cracked the valve to blow out any dust and attached the
regulator. I opened the tank valve and then when I tried to open the
regulator valve, the regulator made these weird puff-puff-puff noises
and the low pressure needle jumped up and down. I then shut everything
down and purged the system. I asked around and it was suggested to me
that it was probably the acetone. Is this a problem that will sort
itself out as the acetone settles back down, or do I now need to have
the regulator serviced?
Also, I am a little rusty, so I would like to ask if I have the proper
start-up/shut-down procedure. Step one, make sure that the regulator
valves are closed. Step two, open the O2 all the way and open the C2H2
about 1/4 turn. Step three, open the acetylene valve on the torch
about 1/2 turn and open the regulator valve until the low pressure
needle reads 3-5 psi (I want to cut 1/8" and 1/4" mild steel) and then
close the acetylene valve on the torch. Step 4, open the O2 valve on
the torch body all the way and open the O2 valve on the cutting
attachment about 1/2 turn. Step 5, open the O2 valve on the regulator
until the pressure is about 20 psi with the O2 lever depressed and
close the valve on the cutting torch. Step 6, open the C2H2 valve
about 1/4 turn and light the torch. Step 7, open the O2 valve on the
cutting torch until the flame is neutral.
Step one, close the O2 valve, followed by the C2H2 valve. Step 2,
close both tank valves. Step 3, open the C2H2 valve about 1/2 and
release the gas until the low pressure needle drops to 0 psi. Step 4,
close the C2H2 regulator valve followed by the C2H2 torch valve. Step
5, open the O2 valve on the cutting attachment about 1/2 turn until the
O2 pressure drops to 0 psi. Step 6, close the regulator valve,
followed by the valve on the torch body and then the valve on the
Is that correct?
Thanks for your help,
Here are the written notes that go with Ernie's gas welding class. Enjoy - GWE
Oxy-fuel welding/heating/cutting/soldering/brazing class
cylinder is low pressure, light wall construction, filled with plaster
saturated with acetone, acetylene is dissolved into the acetone.
Analogous to soda water, when bottle cap is removed, gas bubbles out
steadily for a long time until finally exhausted. Dissolved acetylene is
stable, safe, gaseous acetylene is very unstable and explosive and
DANGEROUS. There is a maximum rate of acetylene withdrawal which must not
be exceeded, often cited at 1/7 the tank capacity. For example, a tank
holding 330 cubic feet has a maximum withdrawal rate of 47 cubic feet per
minute. Attempting to withdraw acetylene in excess of this rate will draw
acetone along with the acetylene, with nasty effects like large pops. An
acetylene tank approaching empty can be detected by little green flashes
in the flame; this indicates tiny amounts of acetone being drawn out and
the tank should be taken out of service and refilled.
MC originally used to fuel motorcycle headlamps
B originally used to fuel bus headlamps (acetylene headlamps)
cylinder is high pressure, just gas, very heavy wall construction.
two kinds of cylinders, industrial or medical
same gas, medical cylinders cleaned to much higher standards
cylinders are never mixed; mixing cylinders can lead to huge fines
other LP gases
LP means liquid petroleum, and includes propane, chemtane, MAPP, flameall
and also propylene and propadiene; all basically sexed up propane. All LP
gases come in low pressure cylinders like propane, and in fact you can
swap propane 25 gallon (aka "100 pound") propane cylinders for Chemtane
cylinders at Central Welding. Chemtane is a little more expensive than
propane, much cheaper than acetylene.
"Rental" cylinders and "Ownership" cylinders are 2 completely separate
entities. Rental cylinders will have a welding supplier's name imprinted or
embossed on the "Head-Stamp Ring" on top of the cylinder. These cylinders
can NEVER be owned, ever ever ever. If you buy one used and try to have it
filled, it will be seized by the supplier and returned to the supplier on
the head-stamp. Many of the less expensive cylinders seen on craigslist are
actually rental cylinders, although the seller often denies this. A useful
strategy is to program the number of a local welding supply into your
cellphone before you go look at a set of cylinders. If there is any writing
on the neck ring, call the welding supply while you are standing in front
of the cylinders. Many sellers have a remarkable change in attitude when
you look up at them and inform them that the welding supply wants to know
where they live so they can call the sheriff. When you do get owner
cylinders and swap them for full ones, save the receipt from the welding
supply. When it comes time to sell the cylinders such receipts end all
discussion about owner/rental.
Ownership cylinders can have a blank Head-stamp ring, a military head-stamp
(USN, USAF), a school head-stamp (Univ. Wash., South Seattle Comm, Coll.)
or a private company head-stamp (Boeing, Caterpillar). With ownership
cylinders, you don't necessarily own THAT CYLINDER, but rather A cylinder
OF THAT SIZE. You simply swap your empty cylinder for a full one, the same
size, at the supplier, and pay for the gas.
All cylinders must be hydro-tested every 7 years. If you buy used ownership
tanks that are out of date, you will have to pay for a hydro-test before a
supplier will accept them. The supplier will send them out and charge you
for the test. If the cylinder passes they simply give you credit for a tank
of the same size, and you pay for the gas. You can request the same tank,
but you will have to wait for it to be sent out, filled and returned.
Usually 2-3 weeks. Tanks have not changed for over 70 years. You will
occasionally find high pressure cylinders in the US with German Swastikas
on them. These were seized military tanks from WWII, and will be around for
a long time since they were built more heavily than most cylinders.
All fuel gas cylinders have left-hand threads except A, B and MC acetylene
tanks. A, B and MC cylinders are a holdover from the old days when they
were used to power Automobile, Bus and MotorCycle headlights.
MC tanks are the smallest acetylene tanks used, and are popular with
jewelers and plumbers. B tanks are one step up and are popular with
jewelers and hobbiests. A tanks are very rare, and are in-between B and MC
Welding Cylinder Data (cap. in cubic feet)
Tank Designator Capacity Height Dia.
K 251 51" 9"
S 156 46" 7 3/8"
M 125 47" 7"
Q 92 30" 7 1/8"
Tank Designator Capacity Height Dia.
#5 350 45" 12"
#4 150 38" 8"
#3 75 29" 7"
made from dripping water on calcium carbide, acetylene used to be user-
generated for everything from toy "carbide cannons" to household gas
installations which had an acetylene generator in an outbuilding,
generally a blockhouse about 100 feet from the main home with 3 walls
made of concrete blocks and the 4th wall (the one that faced away from
the house) made of wood so that if the acetylene exploded, the wood wall
would fail and the blast energy would be directed away from the home.
Acetylene generators were also used in industry and are still around as
quaint period pieces, but insurance practices now dictate that acetylene
production all be done in large plants. The welding gas industry would
love to see acetylene go away entirely because of the astronomical
insurance costs associated with handling it, but it is necessary for
welding as no other gas has its attributes of heat without excessive
amounts of elemental hydrogen being introduced into the weld metal.
very expensive fuel
only fuel gas appropriate for welding steel
Propane/Chemtane/MAPP/Propylene/Flameall: (LP gasses)
not suitable for welding, best choice for heating or cutting
use same regulator as acetylene
propane is a much cheaper gas than acetylene
some tips on looking for quality
inspect end of key
inexpensive regulators have flat tip
good regulators have cone tip
next step up is the best general quality found - a ball bearing swaged
into end of key.
some high end regulators have tip shaped to fit between 3 ball bearings
large diameter diaphragm -> more precision control
Victor, Airco, Smith regulators are good brands
old Union Carbide regulators are "Rolls Royce", but very heavy
It often makes sense to buy high quality older 2-stage regulators and pay
to have them rebuilt (Seattle has an excellent torch repair vendor; Hansen
& Miller in Ballard) as this can be about as expensive as buying medium-
quality regulators new and can give much better quality.
Single Stage regulators slowly decrease their output pressure as the tank
Double Stage regulators adjust for the dropping tank pressure to maintain a
constant output pressure.
Single stage regulators cost less to buy and repair.
On high pressure cylinders always crack the valve slowly, doing it fast
breaks down regulator seats. If a regulator is leaking out the overpressure
valve it usually means the seats have been damaged.
Some inexpensive (Harbor Freight) regulators, the diaphragms aren't
finished cleanly so they stick. This leads to pulsing of the pressure so
you will see instability in the flame cone. It can make these difficult to
Both acetylene and propane cylinders use a CGA 510 connector (aka a POL
fitting) so you can generally use an acetylene regulator on a propane tanks
but most acetylene regulators are set up for the range 2-15 psi so if you
plan to use more propane than that you should either get your acetylene
regulator modified to use a stronger spring and different gauge or you
should use a regulator set up for propane. In addition, once you use a
regulator for propane (which leaves tarry residue inside) you should not go
back to acetylene with that regulator, as the acetylene gas can react with
the tars and this is dangerous. (This last according to Victor customer
Nickel plated, excellent welding torches, straight cutting torches have a
strange feel to them. Fuel is mixed in cutting tip. High quality gear,
very expensive. Tips are expensive because they are made such that they
have no exposed seats and as such are much less likely to be damaged.
Ernie feels their valves are somewhat less robust than others.
Once king of the industry, Airco (the company) got broken up, part went
to Concoa and part went to Koike. Both now make torches and Koike is said
to make very good Airco tips. Fuel mixed in tip. Ernie feels their valves
are also slightly less desirable. Airco tips are expensive and have
exposed seats. Airco combo torches are available in the smaller 700
series, and the larger 800 series. The 800 series has stainless steel
threads where the tips and cutting attachment connect, making them much
more durable than most other torches that have brass threads. The 800
series also have bigger stronger valves than the 700 series.
very common, parts everywhere, cutting tips least expensive. Fuel mixed
in torch body. Best valves available. In their combo torches, the 315 is
larger, heavier, has much better valves. The 100 is small, light, and
thus easier to store. The 100 has variants: the thread on top can be
smaller (indicated by the prefix J i.e. J100) or larger for the plain 100
series. The J100 handle takes a 1250 or 1260 cutting attachment and the
100 handle takes the 1350 attachment. Modern Victor torches (indicated by
FC suffix) have flash arrestor/check valves built in, which can be more
compact than separate flash arrestor modules but these can clog and
sometimes they can't be cleaned so this can lead to an expensive repair.
The smallest generally available torches are called 'aircraft torches'
since they were once used to weld aluminum aircraft skins. They make
excellent jewelry torches. The smallest torch available is the Smith Little
Torch, which has synthetic sapphire orifices in the smallest tips.
Torches are generally made of brass, a soft metal, except the larger
industrial cutting torches which can have manganese bronze, monel or even
stainless steel heads. Any threads which are exposed are subject to being
damaged by careless handling such as being banged around in a toolbox.
Therefore such threads should never be exposed; something should always be
threaded onto them. DIT stores their cutting torches attached to torch
leads. You can cut the connecting nuts off old torch lead before discarding
it, and use the nuts to protect exposed threads on both torches and
On combination torches, do not tighten the nut which secures the welding
tip or cutting torch attachment more than finger tight, even if it has
wrench flats. The wrench flats are intended for disassembly if
the nut doesn't come off easily. Tightening the nut with a wrench can be
tough on the O-rings.
O-rings are generally Viton material (Victor uses Hypalon -
chlorosulfonated polyethylene - according to an older "Welding, Cutting &
Heating Guide"), but may be in proprietary sizes. O-rings should be
inspected periodically for cracks or to see if they have lost their
roundness in cross-section.
If a cutting torch pops the first place to look is at the tip. The tip seat
may be damaged, or the tip may be out of round, or the seat may be dinged.
If the tip is damaged, replace it. If the tip seat is damaged, take the
torch in for repair, it can generally be reamed true, except for Smith
cutting torches, which can't be reamed if the sealing edge is damaged.
Hoses & Connectors
Twin-lead welding hose comes in 2 grades
Grade R is for use with acetylene only
Grade T is for use with any fuel gas including acetylene
3/16" ID hose OK for welding & maybe light cutting
short length of 3/16" hose compacts for storage in a toolbox
not suitable for rosebud heating or heavy cutting
1/4" ID hose is common in many shops, OK for welding and most cutting
3/8" is the largest size used with most torches, for very heavy cutting,
i.e. over 4"
1/2" or larger hose may be needed for extremely heavy cutting or heating
Any scored connector (the flat faces where the wrench fits have a line
scored across all of them, like it's "wearing a belt") has left hand
threads. Torch leads come in A and B sizes (and larger). B size is
9/16-18 and A size is 3/8-24. B size fittings can be used for 3/16", 1/4"
or 3/8" hose. A size fittings are used on 1/8" or 3/16" hose for very
Generally, fuel gasses use LH threads except for A, B and MC bottles
which do not. Quickchange connectors are available at a price, and these
are a great convenience and Ernie uses them, but cautions, "IF you have
to break down your setup or swap torches often, quickchange connectors
are great. If your setup never gets taken apart then skip them.
Obviously oxygen and fuel gasses should not be allowed to ever mix in the
hose; a mixture of oxygen and acetylene can be very explosively unstable
indeed for example. To this end, there are two types of safety devices
commonly used. The first is a set of check valves. Check valves allow gas
flow in only one direction. Installed at the torch, check valves can
prevent unsafe situations. For example, suppose a user draws enough
oxygen out of a depleted cylinder so that the oxygen pressure drops below
the fuel gas pressure. In that case the fuel gas could back-flow into the
oxygen line, which can be extremely dangerous. Flash arrestors are
designed to extinguish a flame internal to the torch, preventing the
flame front from reaching back into the hose. Flash arrestors are much
more expensive than plain check valves, but they often include check
Many currently made Oxy/fuel-gas torch models have built in check valves.
These use synthetic flint and steel to generate a spark. These strikers
are very inexpensive and can last for many years. The steel generally
doesn't wear out, and the flints are renewable inexpensively. What goes
wrong with conventional strikers is that they get bent or rusty.
Ernie loves these. He says they never wear out, ever. If they stop
sparking, a sharp rap on the welding table will always make them spark
Neither striker technology works very well if wet, but the conventional
striker at least works somewhat while the piezoelectric type basically
doesn't work at all if wet. Keep them dry.
It is strongly discouraged to light a torch with a disposable lighter,
although it is done a lot, perhaps foolishly.
Gas welding and cutting requires a #5 lens.
Brazing and silver soldering requires a #3.
Aluminum gas welding requires either a Gold coated didyminum or gold coated
cobalt lens. Old fashioned plain cobalt or didymium lenses are very
dangerous since they do not block UV. There is also a special aluminum
welding lens made by
called the TM2000.
Gas welding rod
Don't mix up gas welding rod and TIG filler rod. TIG filler rod is
designated ER70S-2, and gas welding rod is designated R45.
How to connect, ignite, extinguish & shut down an O/A torch; best practice
Connect the regulators and hoses
Ensure the regulator key is completely released (unscrewed until slack)
Briefly crack each cylinder in turn before attaching the regulator to
remove any debris in the valve head
Attach the regulators to the tanks, attach the hoses and then again crack
each cylinder valve and turn in the regulator key to allow gas to flow for
a short time to blow any debris from the hoses, then back the regulator key
back out and shut off the cylinder
Attach the torch
Slowly crack each cylinder in turn until tank pressure shows. Open the gas
cylinder about one full turn; open the oxygen cylinder all the way until
hand-tight against the top. (This stops oxygen from leaking.)
Slightly open each valve on the torch in turn, adjusting the regulator to
the desired flowing pressure, then shutting off the torch.
With a solution of dishwashing soap in water, leak-test the connections.
The torch is now ready for lighting.
Slightly open the torch fuel valve and light the torch.
Continue opening the torch fuel valve until the soot just disappears from
the flame. Then slowly adjust the oxygen valve until the desired flame
(carburizing, neutral, oxidizing) occurs.
The torch is now ready for welding.
Shut off the torch by first shutting off the fuel. However, if a cutting
torch pops out and a loud "singing" sound is heard from the torch it means
the flame is burning inside the torch body and in this case the oxygen
should immediately be shut off first.
To shut down the torch and regulators, first extinguish the torch (as
above) and then shut off each cylinder in turn. After shutting down each
cylinder, open the respective valve on the torch to bleed the pressure out
of the regulator and then spin out the regulator key until all the spring
pressure is released and the regulator key spins freely, then shut the
The system is now properly shut down and ready for disassembly or storage.
How to ignite an O/LP torch
All of the above procedure is correct but it is often easier to light an
oxygen/LP torch if a small amount of oxygen is allowed to mix with the LP
fuel gas before lighting. Harold (from Hansen & Miller) asserts that the
best way to light an O/LP torch is to slightly open the fuel valve, light
the flame, then add a little oxygen, then open the fuel valve some more,
then again add more oxygen, then open the fuel valve to the final setting
and then finally adjust the oxygen valve for the correct flame.
Torch setup, connection & lighting on several fuels & torch types
Torch welding basic techniques on 16 ga. sheet steel
don't wear gloves, bend the welding rod about 75°, hold torch in your
right hand and the welding rod in your left (assuming you're right-
handed), weld right to left (forehand), using the torch to make a puddle,
then dipping the rod directly into the puddle briefly then pulling the
rod back out, then immediately engaging the puddle with the torch again.
The torch and wire should more or less line up, with your hands out of
line. In that way, the welding gas will reflect and act as preheat. Pic:
tack both ends first, otherwise similar, but the edges will melt a lot
faster than a flat bead
need more heat than a butt joint, tack both ends first, also here you're
joining an edge to a flat, so the edge will want to melt first, so keep
the heat more on the flat and make sure to add the filler rod to the back
of the puddle. The torch flame moves rapidly back and forth along the
joint to keep the weld puddle fluid.
Outside corner joint
uses a smaller flame than a butt joint; tack both ends first, arrange so
joint is horizontal and at top of vee, don't need any filler rod, just
wash the puddle along with the torch
worst case for edge/flat difference, here flame is aimed 1/8" from edge
of top piece, while filler rod is added between the flame and the edge.
Be very aggressive in feeding the filler rod or the top edge will melt
TORCH CUTTING LECTURE:
Cutting tips are often fouled right at the tip with slag. It may be
possible to hold the lit tip against a piece of pine until sufficient heat
builds up in the tip to cause it to pop out, which often forces the fouling
slag out. Often a tip is slightly dirty and can be cleaned with a set of
tip reamers. Tip cleaners should be used very gently and carefully as they
perturb the precision tip geometry.
These are one-piece tips, generally made of copper.
These are two-piece tips, which are not always made of copper. The inner
piece is generally recessed slightly from the outer part. Although there
are many types of tips made for different LP gasses, they are often
similar and may work acceptably if interchanged between different LP
gasses. In other words, a MAPP tip may well work well with propane or
chemtane or propylene.
Never ever use any LP tip with acetylene, it will melt the end off.
Some safety issues
Hot fragments can still be red-hot on the floor, and they will melt right
into and maybe even through your boots. Watch carefully where you step, and
it doesn't hurt to have a blacksmith-type slack tub around full of water,
so if you do get a "hot foot" just dunk in your whole foot, boot and all,
Falling cut-off steel can be heavy, sharp and red-hot, a wicked
Hot slag (sparks) hold a lot more heat than welding spatter - a built-up
ball of slag dropping on you can make a 3rd degree burn.
Loose threads on jeans can ignite, it's a real good idea to have a fire
extinguisher in the area, test it regularly, and know how to get to it and
OXYFUEL TIP CHARTS
Victor Acetylene Cutting Tip Chart
- Cutting Tip Series 1-101, 3-101, 5-101
METAL TIP OXYGEN FUEL SPEED KERF
THICK. SIZE PSIG PSIG I.P.M. WIDTH
1/8 000 20-25 3-5 28-30 .04"
1/4 00 20-25 3-5 27-30 .05"
3/8 0 25-30 3-5 24-28 .06"
1/2 0 30-35 3-5 20-24 .06"
3/4 1 30-35 3-5 17-21 .07"
1 2 35-40 3-6 15-19 .09"
2 3 40-45 4-8 12-15 .11"
3 4 40-50 5-10 9-12 .12"
4 5 45-55 5-10 8-11 .15"
CAUTION: AT no time should the withdrawal rate of an individual acetylene
cylinder exceed 1/7 of the cylinder contents. If additional flow is required,
use an acetylene manifold system of sufficient size.
Airco Acetylene Cutting Tip Chart
Metal Cutting Oxy(psig) Acet.(psig) Hand(ipm) Machine(ipm)
Thickness Size #
¼ 0 30 3 16.0 - 18.0 20
3/8 1 30 3 14.5 - 16.5 19
½ 1 40 3 12.0 - 14.5 17
¾ 2 40 3 12.0 - 14.5 15
1 2 50 3 8.5 - 11.5 14
1½ 3 45 3 6.0 - 7.5 12
2 4 50 3 5.5 - 7.0 10
3 5 45 4 5.0 - 6.5 8
4 5 60 4 4.0 - 5.0 7
5 6 50 5 3.5 - 4.5 6
6 6 55 5 3.0 - 4.0 5
Gas pressures are for hose lengths up to 25?. Increase pressure for longer
lengths of hose.
(snip lots more good stuff)
Grant, it isn't quite this clear cut. My cylinders (Mnpls area) have
various supplier's marks on the headstamps. I swap MT's for fulls, but
the supplier(s) and I agree that I own a certain number of various
sized cylinders. If I want to get them filled at a different supplier
then I merely need to transfer ownership records to that supplier --
which is just a matter of a phone call from supplier to supplier. They
do that routinly, no hassle at all. I do not pay any lease charges.
The smaller ones (40 cu ft and under) don't have that requirement;
about anyone will fill them and there is no record of ownership.
You're right, Don, but the text is what Ernie teaches and it's a real good place
to start. He teaches people to be leery buying used welding cylinders. It is
possible that a used cylinder with raised lettering on the neck ring is an owner
cylinder, but generally it isn't.
>> "Rental" cylinders and "Ownership" cylinders are 2 completely separate
>> entities. Rental cylinders will have a welding supplier's name imprinted or
>> embossed on the "Head-Stamp Ring" on top of the cylinder. These cylinders
>> can NEVER be owned, ever ever ever. If you buy one used and try to have it
>> filled, it will be seized by the supplier and returned to the supplier on
>> the head-stamp.
> (snip lots more good stuff)
> Grant, it isn't quite this clear cut. My cylinders (Mnpls area) have
> various supplier's marks on the headstamps. I swap MT's for fulls, but
> the supplier(s) and I agree that I own a certain number of various
> sized cylinders. If I want to get them filled at a different supplier
> then I merely need to transfer ownership records to that supplier --
> which is just a matter of a phone call from supplier to supplier. They
> do that routinly, no hassle at all. I do not pay any lease charges. >
> The smaller ones (40 cu ft and under) don't have that requirement;
> about anyone will fill them and there is no record of ownership.
Yup. Certainly a good practice would be (as you alluded) to ask the
seller where he gets them filled and then call that place (before
buying them) to inquire about what must be done so you can get them
filled later. If the seller balks at that, walk away from it.
>>> "Rental" cylinders and "Ownership" cylinders are 2 completely separate
>>> entities. Rental cylinders will have a welding supplier's name imprinted or
>>> embossed on the "Head-Stamp Ring" on top of the cylinder. These cylinders
>>> can NEVER be owned, ever ever ever. If you buy one used and try to have it
>>> filled, it will be seized by the supplier and returned to the supplier on
>>> the head-stamp.
>> (snip lots more good stuff)
>> Grant, it isn't quite this clear cut. My cylinders (Mnpls area) have
>> various supplier's marks on the headstamps. I swap MT's for fulls, but
>> the supplier(s) and I agree that I own a certain number of various
>> sized cylinders. If I want to get them filled at a different supplier
>> then I merely need to transfer ownership records to that supplier --
>> which is just a matter of a phone call from supplier to supplier. They
>> do that routinly, no hassle at all. I do not pay any lease charges. >>
>> The smaller ones (40 cu ft and under) don't have that requirement;
>> about anyone will fill them and there is no record of ownership.
If you lay an acetylene bottle on its side you are not supposed to use it
until it has been sitting upright for up to 24 hours.
The time varies from different sources. Some say for as little as four
I took just the bottle back to the store and
exchanged it, but on the way home it tipped over
Thanks for your help,
You should be OK. The torch will probably sputter a little until it gets
the acetone out of it's system... I loaded mine up once trying to run a big
rosebud on tanks that were too small (actually, it works OK when the tank is
nearly full, but, when it gets much below a half, it starts drawing
acetone...) and seem to have suffered no ill effects. And a buddy of mine
had an employee try to use up the last bit of acetelyne and had put a
significant amount of the acetone through the torch before he caught him.
It didn't seem to hurt the torch any, but the gas vendor was none too
Well, I finally got the opportunity to fire it up, but the flame pulsed
stronger and softer. Is this just a case of acetone needing to burn
BTW, I was looking at wikipedia's page on oxyacetylene welding and
cutting and it recommended shutting off the acetylene valve first. I
couldn't remember which one I was taught, so I followed those
instructions, which caused a nasty pop. I thought that one should
probably shut off the O2 first, but again, this might be an acetylene
problem. Is it?
Thanks for your help,
It sounds like a regulator problem to me. Can you borrow a known-good acetylene
regulator to try?
Shutting off the acetylene first is the recommended procedure UNLESS you are
using a real big heating tip, in which case it might pop loudly. In that case,
what I do is to step from one valve to the other until both are low, then shut
off the oxygen first.
Cost to repair a given regulator would depend on
what brand it is because of availability of parts. Some can't be
repaired. In my area, rebuilt name-brand regulators can often be
found at the welding store for under $40 with no tradein.