An experiment oxy/acetylene vs air/acetylene

hi all

i just did an experiment on the 2 torches I have. the oxy acetylene
is a Meco Midget, and the air acetylene is a smith. I used
comparable size tips for the equivalent flame size. at work we had
been having trouble with our annealed metal which we use Brass360,
this is one of my jobs for museum mount making, after we fabricated
the mounts to specs for the objects then we have to form and fit them
to exact curves and forms to hold the objects hovering above the
decks.it is delicate and precise work, and can not be done easily
when the metal is too hard. so the experiment was of 2 bars at 1/2
inch by 1/8 thick by 6 inches long. on a solderite pad, took the air
acet. torch to the metal evenly to a cherry red kept it for about 5
seconds and let it cool before quenching, same with the oxy
acet.torch, brought it to a cherry red evenly, let it cool and
quench. the test was to hold the bar by it’s 2 ends and bend it in
the middle a gentle curve, the one with the Air acetylene bent very
easily, the one with the Oxygen and acetylene was hard to bend,it did
bend but was painful on the hands, and the curve achieved was
shallower.So do any of you out there have any ideas as to why this
would be the case, any metallurgical explanation is welcome. my
thought was that once you get the metal to a cherry red, evenly it
does not matter what the heat source is, as long as the metal temp.
came up to annealing point. both pieces were heated to cherry red
with a large flame to cover as much of the metal as possible at once.
I never had trouble like this with silver or gold or copper, but this
brass seems a little different? Any ideas? anyone?

Atelier Hratch Babikian
contemporary Jewelery and sculpture

I have no idea what I am talking about, I do use a air acetylene
torch a pipe fitter gave me, and the only thing I can think of is
that the oxy/ace torch heated the outside of the metal faster than
the air torch. So the oxy metal was annealed on the outside layer,
and not in the inner core.

Roxy

I heard from one person and was wondering if there were more people
with opinions on this, sent a Msg to David Huang, and have come to
theconclusion that there is a fairly large difference between copper
and bronze VS Brass, I am talking about working the material in
practice, forming and forging set aside. my ezxperiment and question
is with the annealing and soldering point.

i just did an experiment on the 2 torches I have. the oxy
acetylene is a Meco Midget, and the air acetylene is a smith. I
used comparable size tips for the equivalent flame size. at work we
had been having trouble with our annealed metal which we use
Brass360, this is one of my jobs for museum mount making, after we
fabricated the mounts to specs for the objects then we have to form
and fit them to exact curves and forms to hold the objects hovering
above the decks.it is delicate and precise work, and can not be
done easily when the metal is too hard. so the experiment was of 2
bars at 1/2 inch by 1/8 thick by 6 inches long. on a solderite pad,
took the air acet. torch to the metal evenly to a cherry red kept
it for about 5 seconds and let it cool before quenching, same with
the oxy acet.torch, brought it to a cherry red evenly, let it cool
and quench. the test was to hold the bar by it's 2 ends and bend it
in the middle a gentle curve, the one with the Air acetylene bent
very easily, the one with the Oxygen and acetylene was hard to
bend,it did bend but was painful on the hands, and the curve
achieved was shallower.So do any of you out there have any ideas as
to why this would be the case, any metallurgical explanation is
welcome. my thought was that once you get the metal to a cherry
red, evenly it does not matter what the heat source is, as long as
the metal temp. came up to annealing point. both pieces were heated
to cherry red with a large flame to cover as much of the metal as
possible at once. I never had trouble like this with silver or gold
or copper, but this brass seems a little different? Any ideas?
anyone? 

Atelier Hratch Babikian
contemporary Jewelery and sculpture