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Acetyline gas flame color

I am using an Acetyline Smith torch.All of the fittings are correct
for the B tank.Only Acetyline, no oxygen. Even though the flame
should be blue, I am getting an orangy( the cone is bluish) colored
flame. I tried changing the fittings with another Jewelers(teacher)
torch to try and Isolate the problem.I thought it was solved because
the flame was blue,now its orangy again.What makes the flame blue as
opposed to orange?



Is your tank almost empty ? Trying to get the last bit of gas tends
to suck up some of the acetone the acetylene is dissolved in.

Another possibility is a dirty torch tip. There are some very fine
filters and orifices in there. Try a different tip. It is possible to
disassemble and clean/replace these parts but it might be time for a
new tip.

Demand Designs
Analog/Digital Modelling & Goldsmithing

The flame is blue because of the abundance of oxygen. the burners for
oxyacetylene are different to those when using gas/air. When you burn
acetylene without excess oxygen it tends to soot very badly and this
is what makes your flame very orange. The nozzle will become blocked
and may overheat. yopu really need to change your set up to use
oxygen with acetylene or use propane or natural gas with a suitable
air torch. Oxyacet can easily burn holes in whatever you are doing as
the oxygen scavenges at high temperatures…


I am only familiar with oxy-acetylene, but you say that when you
changed fittings (tips?) with another torch you got a blue flame,
which went orange over time. The blue flame is the result of a good
mix of oxygen with the acetylene before the mixture is ignited at the
end of the torch tip. You say you got the blue flame when you first
used the new fittings, so your fuel/air mixture is probably good.

Another characteristic of acetylene is that when incompletely burned,
it produces lots of soot. I suspect that the hot tip is accumulating
soot just inside. Particles of soot will blow out with the gas/air
mixture and cool your flame, making it orangey. Other than adding an
oxygen tank or cleaning your tip before each use, I don’t know what
you can do to stop this.