water torch question/s

Hi,

regarding the ongoign saga of trying to get my torch working, it was
suggested that I try O2 in the torch instead of compressed air.
Given I don't have an oxygen setup (bottles and reg) and the recurring
bottle ental is a bit pricey, I was curious about making my own O2 by an
electrolysis method.

Knowing that some people here have had experience with water torches, I was
curious about the pressures (if any) that you set the water torches to.....
I've tried reading up on it, and infer that most systems create the gases
(captured seperately) and deliver them to the torch at low pressures. but
then I read about oxygen concentrators delivering pressures in the region of
15 psig.

I have the tools to construct a fairly basic system based on seperate gas
collection, and running off a 48VDC battery bank, but if I am required to
deliver at a specified pressure, I may have problems depending upon the
required pressure.

Thoughts? pressures?

Thanks,
Des bromilow
Brisbane
OZ

On Mon, 27 Sep 2004 18:53:21 -0700, in ”õ "Des Bromilow"
wrote:

Hi,

regarding the ongoign saga of trying to get my torch working, it was
suggested that I try O2 in the torch instead of compressed air.
Given I don't have an oxygen setup (bottles and reg) and the recurring
bottle ental is a bit pricey, I was curious about making my own O2 by an
electrolysis method.


it can be done, but is not all that simple. However, if you do it with a home
built setup, remember that you're also generating hydrogen, and the little torch
works quite well using hydrogen and oxygen as fuel and oxidizer. Most industry
standard "water torch" designs do not seperate the oxygen and hydrogen streams,
but leave the gases mixed, as the automatic mixture is perfect for complete
combustion. However, oxy hydrogen is enormously hot. Too much so for many uses,
as well as too hot for many torch designs, in part because the combination burns
so rapidly that unmodified, the flame tends to travel back up into the torch,
instead of staying at the tip. "water torches" solve this by passing the gas mix
through a vapor fluxing unit, and the absorbed solvent vapors lower the speed an
temp of combustion to something manageable, as well as giving the flame a
reducing nature, which is useful for soldering.

A limit to making your own oxygen generator is that you'll have little control
over the oxygen pressure you generate. Normal water torches are not adjustable
in this regard. They operate at quite low pressures, with a swicth that simply
turns current on and off to keep the pressure where the system wants it. It's
not so simple to build a system to give you varialbe pressures such as the little
torch is designed to use.

Knowing that some people here have had experience with water torches, I was
curious about the pressures (if any) that you set the water torches to.....
I've tried reading up on it, and infer that most systems create the gases
(captured seperately) and deliver them to the torch at low pressures. but
then I read about oxygen concentrators delivering pressures in the region of
15 psig.

That was my next suggestion. Oxygen concentrators extract oxygen from the air, I
think, rather than electrolysys. Their output is not as pure oxygen as bottled,,
but it's fine for a torch setup. I seem to recall the deliverd mix is something
like 85 to 90 percent oxygen, which should be fine. I've seen the things for
sale on ebay, and you might find used ones for sale from local medical supply
firms, perhaps units that ar not longer able to be certified for medical use, or
are out of warranty, etc. Prices vary. You don't need anything more than the
smallest such unit for a little torch.

But from what i've seen, frankly, you'll still be spending more money than to set
up an oxygen tank. I'm not sure of prices where you are, but here, a small oxy
tank and cheap regulator would cost me a bit over a hundred dollars, with refils
for the tank perhaps twice a year if I used the torch frequently, and those
refills cost around 10 to 15 dollars. Not that excessive, really. (prices I
gave are in U.S. dollars. )

Peter