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Black sap cloud coming out of the torch

New question:

After moving my store and studio to a different town I found out
that its not allowed there to use Propane. I switched to Acetylene
but I’m very unhappywith the black sap cloud coming out of the torch
every time I switch it on. Is there any trick to avoid this?

Edith Schneider

I switched to Acetylene but I'm very unhappywith the black sap
cloud coming out of the torch every time I switch it on. Is there
any trick to avoid this? 

Turn on gas & oxygen at the same time before lighting your torch.

After a few dozen pops you’ll figure out how much/how little to turn
the valves.

Paf Dvorak

Crank a little oxygen open with it when you light it to see if that

  1. be sure to let the tank settle after moving and BE SURE the tank
    is upright for this and for use.

  2. If you are talking about the good deal of soot from the lit
    burning acetylene, this is the nature of the gas. Start the torch
    with a minimum of flame and get the O2 to it fast, or lite it by an
    exhaust vent. Acetylene is hot but dirty…

Only way to stop the back stuff is:

  1. don’t lite it or
  2. don’t put it out.

john dach

I would be curious as to why they don’t permit propane. Perhaps, it’s
because propane is heavier than air and they are afraid that leaking
gas would settle in a low area (basement, etc.) where it might get
occidentally ignited.

I prevent the black soot from the acetylene by turning on the oxygen
first. but, very low. So low that I have to hold the torch tip close
to my face or ear in order to tell that there is any oxy coming out
of it. Then, turn on the acetylene a little bit and light the torch
and then adjust for the flame that I need for the job at hand. If I’m
doing a fair amount of torch work I keep an alcohol burner going on
my bench to use to light the oxy/acetylene torch (rather than using a
flint striker.)

– alonzo

No propane in a town? How do folks operate their grills? I wonder if
someone was telling you a truth. Beyond that you have, obviously, a
propane torch- NOT designed for acetylene. I don’t know what "sap"
is as used in the sentence, but you may need a different regulator
and perhaps new hosing and you will need to clean out the orifices in
the burner. Perhaps replacing any “o” rings as well. It would help to
know which torch brand and model you have. But you should disconnect
the Acetylene and drain the line at least, until you figure out where
the black soot is coming from. I find it hard to believe that it was
any build up in the hose, but rather may be in the actual torch tip
and burning the hotter acetylene has pushed it out of the hose and at
the contact with room air combusted. (though a remote possibility).

Many people not that familiar with torches and all the potential
combinations of fuel gas, air and oxygen don’t realise torches are
not designed to be used with gasses other than that which came with
the intended original set up. as marked on the box, regulators, etc.
You should get out your operator/owners manual first and troubleshoot
using their recommendations before trying anything other than a good
cleaning, to the orifices on the burner tip(s) and the inlet (the
point it connects to the handpiece) changing the hosing and
regulators for the appropriate gas, and disconnect the acetylene
right away. Don’t use it if there is a cloud of anything coming out
of the torch! Also don’t use any “tricks” to remedy the situation
have a professional install or set up the system for you as something
is clearly wrong. Consider hard line natural gas as a source for your
fuel gas if it is true that propane isn’t allowed. (I can’t imagine
that myself, as acetylene is perhaps more dangerous!)… you wouldn’t
have to refill anything but an O2 tank with natural gas- if its
available in your area. Check your insurer while you are at it to
make sure this place you live in allows anything like a small studio,
and get a rider added if not (there are articles in the Orchid
archives on Insurance for studios). If regulations where you live are
that strict you may be limited to a butane torch. I would double
check the info you got on propane- go to a home store in the plumbing
section and see if they sell torches and gasses- if propane is there
I’d switch back to it after having changed the hose and having the
regulators checked by the seller or manufacturer, however if you used
a propane regulator with actylene it may have voided that
warranty!..good luck. rer…

Hello Edith.

Please STOP using the torch!!!

Are you using acetylene only?
Or is this an oxy-acetylene setup?

Are you using your propane torch with acetylene? The orifice is much
too big for this and this might be why you are getting the “black sap

Just the opposite will happen if you try using an acetylene torch
with propane, the torch will not light! Or it will but the flame will
constantly go out!!!

If however you are using an acetylene torch with the gas then
perhaps you have a clogged filter.

Some torches have little filters over the orifice that get clogged
quite easily.

If, after a soaking in your ultrasonic, the torch still does this, I
would either return the torch where you got it, or if it is an older
torch, invest in a new one.

Please don’t take this as being rude, but, where do you live that
they “will” allow acetylene but not propane, usually its the other
way around.

Concerning the laws in your area, Is it a matter of the size of the
tank? I once lived in an area that would only allow two 1lb
disposable propane canisters indoors.

Anything larger was prohibited, Acetylene was completely off limits!

I wish you the best.

Generally the building code regulations about propane restrict having
propane tanks inside or too close to a building. We heat with propane
and our tank had to be a specific minimum distance from our house.
Propane is a bomb waiting to go off, so it’s better to have its
storage tank located where it can do the least amount of harm. Gas
grill tanks. it’s always recommended that they be sited away from
overhanging roofs, like porches. It’s one of the reasons that decks
became popular.

Hope this is useful info,
Linda Kaye-Moses

You may have been misinformed about not being able to use propane in
you town/state.

In many areas it is illegal to store propane indoors so a tank is
installed outdoors and a line is run into the house, shop, etc.

Check with your local government so you will have first hand info on

Tom Kuzia

I am surprised that acetylene would be allowed. I have always
thought that acetylene is much more hazardous than propane.

Janet Kofoed

A problem with propane is that it is heaver (denser) than air
(acetylene is lighter than air.) Leaking propane gas will settle in
low places (like basements) where it could be inadvertently ignited
by something like a spark from an electric motor (sump pump, etc.) or
a water heater, etc…

Propane is used for cooking and heating on boats where there is a
’low place’ (the hull) for the gas to collect. There are many
precautions taken here to prevent unexpected explosions (special
ventilation, tanks located in special lockers with overboard vents,

but still, there are many explosions/fires caused by propane leaks
on boats every year.