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Oxygen fuel mixture or just acetelyne?


#1

Basically right now I am doing some tool shopping and I am facing
the issue of “what torch to buy?” I am not sure whether to choose
oxygen fuel mixture or just acetelyne? I am really looking for a good
all-around torch that I can anneal, solder, fuse and maybe do light
scale casting. Right now I’ve been looking at the Smith “Little
torch” and the Smith “Silversmith” Anyway, do you have any
suggestions? Can the “little torch” anneal larger sheet metal?
heavier gauge wire?


#2

Jakob,

If you get a propane/oxygen torch, get one with the capacity to do
large soldering jobs, like melting platinum or 5 oz. of sterling.
You can also get a tiny tip and do the finest of soldering jobs.

I’d highly recommend a Meco Midget, as the interior “plumbing” is
sufficiently robust to be able to push out serious qualtities of gas
if you need a mighty flame under lots of pressure (think platinum).

The “Little Torch” has very small tubing inside, and will limit you
for larger soldering or melting applications. The Little Torch is
great for small jobs, but not for the big jobs.

Jay Whaley


#3

Hello Jakob,

Acetelyne is a dirty gas! Ignite it without oxygene and you get
nasty carbon clouds all over the place(due to the two atoms of C).
It’s a perfect gas to lubricate the inside of your ingot very quickly
which is an advantagee if you poor a lot. Acetelyne (with oxygene)
can reach high temperature (3300 C, 6000 F) compared with butane and
oxygene (1,970 C; 3,578 F) or propane and oxygene (2820 C/5110 F).
Acetelyne however is more expensive here in Europe. The use of
acetelyne needs a different approach of equipment and torche. You do
not need acetelyne for jewellery making, other gas will do the job
aswell and if you realy need high temps, then go for an hydrogen
torch which is very clean and with a different price tack…

Enjoy and have fun
Pedro


#4

Dear Jakob,

The Smith little torch is an excellent all around soldering torch.
With the #7 tip and an oxygen/propane mix I have been able to anneal
a 16-gauge sterling silver sheet as large as 3x3 inches on compressed
charcoal. Also, with this same set-up i have been able to anneal
12-gauge 18-karat round and square gold wire for drawing down.

But, I would not try to cast anything more than 2-3 pennyweights with
it, it just does not have the heat. An oxygen/fuel mix will give you
more versatility than an atmosphere/acetylene torch. Also, Propane
and Natural gas are much, much, much cleaner/safer. Think of your
lungs and your eyes - you will want to be using them for a long,
long time.

Best regards,
Nanz Aalund
www.nanzaalund.com


#5
Think of yourlungs and your eyes - you will want to be using them
for a long, long time. 

You know, I keep seeing this claim when acetylene is mentioned, and
I just can’t stay quiet about it any longer.

I regularly use a Little Torch with a nice portable Oxy-Acetylene
tank set up. I have use Propane, Oxy-Propane and (Ugh) Oxy-MAAP gas
in the past.

Oxy-Acetylene is NOT brighter than propane.

In fact, I’ve found the opposite to be true. Not only do I have a
LOT more problems with “spots” in my vision from the same size of
propane flame, I generally need only a TINY (6 to 8mm long at the
core) flame when I work with Oxy-Acetylene to do the job for
everything but annealing, while a much larger propane flame is
needed, takes longer to do the same work, and generally leaves a lot
more oxides on my work.

That said, I DON’T recommend Acetylene on it’s own. It’s a mess, and
VERY bright.

I can’t suggest the Smith Little Torch enough. It’s a wonderful
little piece of equipment that no one who is soldering more than
casually should do without. No affiliation, just a VERY satisfied
customer.

Lindsay Legler
Dreaming Dragon Designs


#6

I have used my little torch on oxy propane to melt up to maybe 40
grams of silver in an open crucible using the optional rosebud tip. I
also use this tip for annealing, torch enamelling and soldering large
(over 25mm) bezel mounts - even where necessary silver brazing copper
plumbing fittings.

I now use a crucible furnace but the Smith torch can pour out a
reasonably serious amount of heat.

Jen


#7

Forgot to include this in my post to the list, but I have easily
annealed larger (6X6in) sheets of silver with my Oxy-Acetylene
Little Torch.

Do stay FAR away from plain Acetylene.
Lindsay Legler,
Dreaming Dragon Designs


#8
Acetelyne is a dirty gas! Ignite it without oxygene and you get
nasty carbon clouds all over the place 

I don’t understand this – I have used an air-acetylene torch for
years, and I never get that black floating stuff. When I use oxygen &
acetylene together, then that messy black stuff shows up when I
light the torch (which is one of several reasons I don’t use
oxy-acetylene).

Judy Bjorkman


#9

I use a rosebud tip on my oxy-propane mini-torch handpiece and melt
up to 35 dwt in a Wesgo crucible for casting.

Little Torch Multi Flame Tip For Propane, Butane Or Natural Gas
http://www.ganoksin.com/gnkurl/114031

Thought this might interest you.

Linda


#10

I have two torches. One is Oxy-Acet and the other is a straight Acet.
that mixes with room air. I use the straight Acet. about 95 to 98
percent of the time. I also have a little smith and have used it
exactly twice. Just never got the hang of it. When I’ve tried it for
things like jumprings I wind up with a ball of melt. I know it is me
but that is my experience. jacl from sunny and cool Chattaroy Wa.

John (Jack) Sexton


#11

The black soot you sometimes see with the oxy-acetylene combination
is due to a fuel-rich mixture, meaning that the ratio of fuel to
oxygen is too high. Since you have to adjust the oxygen after the
torch is lit, you can get the soot unless you crack open the oxygen
valve on the handset just a hair before lighting. When shutting off,
quickly shut off the flow of fuel after you have shut off the oxygen
to minimize soot.

With acetylene/air combo, the ratio is already set by the orifices
on the handpiece that automatically pull in the right amount of air
for the flow rate of acetylene; thus, no soot because you don’t have
a fuel-rich mixture.

With proper use, the oxy-acetylene mixture will not create soot, but
it does burn about 1000 degrees hotter than air-acetylene, because of
the oxygen.

Also, remember to occasionally clean your torch tips to remove sooty
buildup on them.

Emie Stewart


#12

Dear Lindsay,

Oxy-Acetylene is NOT brighter than propane. 

It is not what you can see with the naked eye that will damage your
eyesight over the long run! My husband is an optician and you are
exposing your retinas to lasting radiation burns by looking at an
Oxy-Acetylene flame without welding goggles. Especially with the
small intense flame created with a smith little torch.

Plus an Acetylene flame off-gasses carcinogenic material which
without excellent ventilation you are breathing into your lungs
daily. I am glad you could not keep silent, but please take action to
protect yourself! –

Nanz Aalund
www.nanzaalund.com


#13
Plus an Acetylene flame off-gasses carcinogenic material which
without excellent ventilation you are breathing into your lungs
daily. 

Sorry, I misspoke in a 2005 MSDS from the state of California, it is
the minor chemical contaminates from gas tanks used in gas compression
that when burned present the carcinogenic risk.(ie. soot?)

Nanz Aalund
www.nanzaalund.com


#14

I have used oxyacetylene for many years. The “icky” black carbon
strands sometimes happen when the fuel is lit but usually this is
because the acetylene valve is open too far. Try lighting a small
acetylene flame, add oxygen to taste and then slowly increase both
gases in stages until you get the flame you wish. This will, at
least, minimize the problem. I will watch to see if I generate soot
when I light my torch. I don’t think I do unless I am careless.
Certainly I don’t produce enough to cause a problem. Perhaps I am
just insensitive to soot.

Gerald Vaughan


#15

Nanz

Plus an Acetylene flame off-gasses carcinogenic material which
without excellent ventilation you are breathing into your lungs
daily. 

The products of combustion of acetylene are Carbon Dioxide and
Water. These are not carcinogens.

You are making a very serious statement here. Where did this
come from?

Regards
Milt


#16

I usually turn on both and light the torch. It takes some practice to
turn them on just enough to be the flame you desire and not get all
that exciting popping.


#17

Acetelyne Toxicological Overview (PDF file)
http://www.ganoksin.com/gnkurl/hpapdf

Acetelyne… Apparently not a real problem, unless you are a
huffer…

Val