Neutral flame with hydrogen?
 

I just set up a new oxy-hydrogen torch set. The first time I ignited the
torch and turned on the oxygen there was no definitive blue cone. How do I
tell when I have a neutral flame?

Thanks very much!

Chris

Chris Fossan wrote:
I just set up a new oxy-hydrogen torch set. The first time I ignited the
torch and turned on the oxygen there was no definitive blue cone. How do I
tell when I have a neutral flame?

Thanks very much!

Chris

Think!!it through
Just get a bit of scrap copper strip say 1mm thick by 25mm wide, place
on your brazing block, light your torch and apply to copper. vary the
oxy/hyd mix on the taps from little oxygen to a lot and watch the metal.
?youll soon see when the flame os oxidising the copper and when its not.

Havnt you done much brazing? if you have you should have run this sort
of trial to set up what ever torch and gases youve used before to suit
the product your joining. if you havnt done any brazing before then why
have you chosen hydrogen as a fuel gas?
Propane with oxygen will be a lot more economical and youll also have
the blue cone you dont have at the moment.

Ted Frater wrote in message
. ..
Chris Fossan wrote:
I just set up a new oxy-hydrogen torch set. The first time I ignited the
torch and turned on the oxygen there was no definitive blue cone. How do I
tell when I have a neutral flame?

Thanks very much!

Chris

Think!!it through
Just get a bit of scrap copper strip say 1mm thick by 25mm wide, place
on your brazing block, light your torch and apply to copper. vary the
oxy/hyd mix on the taps from little oxygen to a lot and watch the metal.
?youll soon see when the flame os oxidising the copper and when its not.

Havnt you done much brazing? if you have you should have run this sort
of trial to set up what ever torch and gases youve used before to suit
the product your joining. if you havnt done any brazing before then why
have you chosen hydrogen as a fuel gas?
Propane with oxygen will be a lot more economical and youll also have
the blue cone you dont have at the moment

************************************************** ****************
Hi Chris,

I used hydrogen for many years to melt platinum, which is very
susceptible to carbon contamination, and also with great success with
all gold and silver alloys. It's not so good for soldering.

There's really no problem to using it, and because it's lighter than
air it won't tend to 'puddle' if there's a leak and is therefore
safer, in MY opinion.

The drawbacks are

1) as you mention, the flames are virtually invisible: if you smoke
cigarettes, gently blow a little smoke at the flame and you can see
it. Other than that, improvise.

2) the burning characteristics of oxy-hydrogen are very different from
oxy/carbon-based gas: the flames do not spread unless they're very
soft, and then of not much use except for annealing. Neutral or
oxydizing flames are almost as thin as a pencil, all the way to the
end.

3) the possibility of hydrogen embrittlement if you're heating up
more-active metals: copper, nickel, etc.

BTW, most people think that Hydrogen burns hotter than other gases. It
doesn't.

Lane